Re: Tek 2230 - Storage does not work.
Hi,
This is getting weirder, but I am sure it means something to someone....
Store is active.
I set up to put a 3.5 V 1kHz signal into CH1, and turned the CH1 sensitivity down to 5mV. *Ch2 is set to ground*
Then Chn 1 displayed a clamped to a square wave version of the input.
movable by Chn 2' position to only show the half the signal (positive) peeks on the CRT.
Now setting Vert Mode to both gives me 2 versions of the clamped. Chan 2 is 2X the amplitude of chan 1.
Chn 1's Position does nothing. But cha 2's position moves both wave forms.
Setting it to Chn 2 gives me one waveform that is 2X.
As I decrease the Chan 1 Sensitivity the waveform begins to round to a sine wave.
Does this and the +5 V on pin 6 and 11 indicate a bad U2101?
Next Q does someone have a TEK 234-0408B-20, they would like to sell?
David
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Show quoted text
--- In TekScopes@..., "chipbee40" <chipbee40@...> wrote:
--- In TekScopes@..., "david_s5y" <david_s5@> wrote:
Thank you for you help!
Is that in store mode?
No, In store mode Pin 6/11 are -2V
Ahh, the settings need to be the same.
Settings 1 Khz 1 Volt sinewave, CH1 0.5V Timebase 0.1mS
Vert mode: Ch1, XY out, BW in ALT
All the storage out exdept for Menue, Select Wave form and Store.
What did you mean by "(Dependent on T/B and flickering unless you toggle the onscreen display)." and "unless CH1 input is overdriven"
OK, I had the scope in 2 CH, so that is the channel switching signal.
With just CH1 on, pins 2/15 are 2Vdc, 4mV replica of input signal using your differential setup on monitor scope.
Pins 12/13 5.8V DC, no visible signal using differential setup unless you turn CH1 down to 5mV to overdrive the signal, then you can see it. If you suspect U2101, put a large signal into CH1, turn the CH1 sensitivity down to 5mV and probe pin 15 and then pin13, you should see the signal in and out. No signal out, I would guess U2101 is shot, not uncommon.
You could also check Pin21 on U2204, using your settings again, you should see replica 500mV input signal, DC shifted -1V, using the CH1 Y shift you can move the signal up to just above 0V
Am I correct to assume you are looking diferentialy at the 2 signal pairs (Pin 2/15 and 12/13) with another scope on add invert.
David
--- In TekScopes@..., "chipbee40" <chipbee40@> wrote:
Have you checked the position of all the jumpers on the storage board?, a lot of Ebay scopes come with them in diagnostic position.
My U2101 is pt no 234-0408-20 (Later version)
Pin 6/11 of U2101 -1.6V
Settings 1 Khz 1 Volt sinewave, CH1 0.5V Timebase 0.1mS
Pin 2/15 2v DC shifted 2V p/p square wave 4mS period (Dependent on T/B and flickering unless you toggle the onscreen display).
Pin 12/13 5.8VDC, no visible superimposed signal even at 2mV/cm on monitor scope unless CH1 input is overdriven.
I just happen to be working on a 2230, it will be back together shortly so if you need more info make it quick.
JC
--- In TekScopes@..., "david_s5y" <david_s5@> wrote:
I am trying to trouble shoot the missing storage traces. Does anyone have the DC voltage levels for Pin 6 and 11 of a working U2101 (MO36E). I am seeing +5.6 Volts which seems intuitively wrong give the 511 Ohm to -5 Volts.
For that matter with a 1Khz 1V sin wave applied to chan 1 set to .5 V per. What should I see on 2 and 15 and 12 and 13?
Thanks for your help!
David
|
Re: S-30 delta standard and P93C pictures for 130
pictures from inside and out.
He is ready. Fresh calibrated. Only a defect tube and a terrible asymmetric smithtrigger signal, but all is perfect now. A very accurate meter.
Made a P93c, acomponent holder, and the S30 also, was just a gamble but after I understood the principle it was just a lot of educated guessing/calvulating while desinging and by measuring while building and it needed only minor adjustments.
Fred
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--- In TekScopes@..., "Egge Siert" <eggeja@...> wrote:
Hi Fred,
Just found the Data Sheet of the P93C Probe. It is just a piece of 93R Coax with a length of 30 1/2" and a connector. I shall send a scan.
Still searching for the S-30 Delta Standard Manual.
Egge Siert
|
Hi ?David , I think you simply click on the attachments button and show the browser where the picture is stored. ?Regarding the + 50 V supply, The supply should be able to start with the ?current gain stages of Q874,Q869, and Q872. The voltage error amplifier should be cut - off as the base of Q860 is much more negative than the base of Q869, which comprises the differential voltage error amplifier . When the power supply is ?+ 50 V, The base of Q860 should be near 0 volts , as the other end of the
differential amp pair , the base of Q869.. At the moment , the current in the diff pair should be all in the Q869 side . The voltage available from the +130 V supply , even though it is substantially less than 130 V, should be enough to cause the output voltage (+50 ) to rise . The + 130 V supply is "lifted" by the + 50 V supply,and th e+ 130 V supply should provide more current to the base of Q872 ?as the supplies increase in voltage? ?I am leaning on one of the transistors in the ?current gain ?stages has no current gain. I suspect the driver transistor , Q869. Perhaps you could unplug it and replace it with a 2N3440 ? it needs to be a transistor capable of a +60 V ?VCE and 1 watt of dissipation . ?The
other likely cause is Q874 , which you can replaced with a 2n 3773 or other high power high voltage T0-3 ?NPN transistor . It looks like some folks are suggesting that it could be replaced with a 2n3055, but the VCE on that transistor is too low in my opinion. ?I have repaired my own 7633 with?similar?problems ?in the past , although it was a long time ago . Mike?
From: "bwex@..."
To: TekScopes@...
Sent: Wednesday, January 25, 2012 12:32 PM
Subject: [TekScopes] Re: 7603 no trace
?
Hello Jimmy and Magnus.
Before I try anything ambitious, I thought that I would attach a picture of 50v part of the low power board with my votage readings written on. Unfortunately, I cannot figure out how to upload a pdf picture of my circuit? Is it possible? Can you exp[lain how to do it?
David.
--- In TekScopes@..., "magnustoelle" wrote:
>
> Quote: Back to the +50V supply: It's a little risky, but I'd suggest to
> remove Q876, monitor the +50V output with your DVM, and power-up the
> scope. ...
>
> I agree.
>
> For the next step, I would simply pull connectors P900/P901, then bridge
> the sense feedback with the respective supply, and measure the supply
> rails again. This requires only five connections and P900/P901 are in
> close proximity, so the connections are easy. This is a linear power
> supply, not a switched mode supply, so operation with no load does not
> harm anything.
>
> I would also pull P971/P962.
>
> Doing so disconnects the power supply from its loads and allows
> isolation of the trouble to a specific circuit / board by re-connecting
> one board after one.
>
> Just keep going, David - one step at a time. We will bring this beauty
> back to life.
>
> Cheers,
>
> Magnus
>
|
Hi,
In a moment of temporary insanity I bought a display unit for an R7912. Does anyone has a manual/info for this beast?
jerry
Jerry Massengale
jmassen418a@...
|
Hello Jimmy and Magnus.
Before I try anything ambitious, I thought that I would attach a picture of 50v part of the low power board with my votage readings written on. Unfortunately, I cannot figure out how to upload a pdf picture of my circuit? Is it possible? Can you exp[lain how to do it?
David.
toggle quoted message
Show quoted text
--- In TekScopes@..., "magnustoelle" <magnustoelle@...> wrote:
Quote: Back to the +50V supply: It's a little risky, but I'd suggest to
remove Q876, monitor the +50V output with your DVM, and power-up the
scope. ...
I agree.
For the next step, I would simply pull connectors P900/P901, then bridge
the sense feedback with the respective supply, and measure the supply
rails again. This requires only five connections and P900/P901 are in
close proximity, so the connections are easy. This is a linear power
supply, not a switched mode supply, so operation with no load does not
harm anything.
I would also pull P971/P962.
Doing so disconnects the power supply from its loads and allows
isolation of the trouble to a specific circuit / board by re-connecting
one board after one.
Just keep going, David - one step at a time. We will bring this beauty
back to life.
Cheers,
Magnus
|
Re: Tek 2230 - Storage does not work.
First I got a couple of junked 2230 storage boards which was how I discovered there are two versions of the storage channel switch in the 2230 and that the 155-0022-00 will oscillate in a 234-0408-20 design. I was looking into modifying my 2230 to use the more common 155-0022-00 when a friend who I was consulting with took pity and sent me a part pull that he thought might be bad but actually worked fine. The 155-0022-00 was used in a number of earlier oscilloscopes like the 7000 series but I do not know about the 234-0408-20. The only extra 234-0408-20 I have or know of at the moment is the bad one with popcorn noise that I replaced. You can find the 155-0022-00 specifications in the Tek Made Integrated Circuits Catalog. On Wed, 25 Jan 2012 19:15:06 -0000, "david_s5y" <david_s5@...> wrote: I just looked at the pictures. Where did you get the 234-0408-20 from?
David
--- In TekScopes@..., David <davidwhess@...> wrote:
Beware that there are two versions of the 2230 storage channel switch
and while they use the same circuit board, there are some discrete
parts changes which need to be made if you replace one with the other.
When I swapped a 234-0408-20, the one with popcorn noise that I posted
about some time ago, with a 155-0022-00 I got uncontrolled
oscillation. I managed to procure a replacement 234-0408-20 instead
of making the changes.
If you measure at pin 21 of the A/D converter, the voltage should be
between about 0.25 and -2.25 volts as you adjust the vertical position
control. If it adjusts within that range and you have no displayed
trace, then the problem is not before this point. I suppose you could
remove R2293 and apply about 1.0 volts directly to the A/D converter
which should generate a vertically centered trace to verify everything
past this point.
On Wed, 25 Jan 2012 17:12:53 -0000, "david_s5y" <david_s5@...>
wrote:
I am trying to trouble shoot the missing storage traces. Does anyone have the DC voltage levels for Pin 6 and 11 of a working U2101 (MO36E). I am seeing +5.6 Volts which seems intuitively wrong give the 511 Ohm to -5 Volts. I measured -2.1 volts in store mode and -1.25 volts in non-store mode
for the 155-0022-00.
I measured -1.62 volts in store mode and -1.11 volts in non-store mode
for the 234-0408-20.
In store mode the voltage changes a bit depending on the channel
selection and alt/chop selection.
+5.6 volts does sound high. Schematic 11 shows the power connections
for the chip on pins 3 and 5 which are not shows on schematic 16. They
should be about 7.4 volts and 1.8 volts although I think it depends a
little bit on which version you have.
For that matter with a 1Khz 1V sin wave applied to chan 1 set to .5 V per. What should I see on 2 and 15 and 12 and 13? I measured about 0.02 volts peak-to-peak to ground at pins 2 or 15
which may seem low but is expected since the impedance is about 50
ohms.
Pins 12 and 13 are the transconductance amplifier outputs into a
cascode so the voltage change there is too small to bother measuring.
I measured about 0.4 volts peak-to-peak at the collector of Q2101.
|
Re: Tek 2230 - Storage does not work.
--- In TekScopes@..., "david_s5y" <david_s5@...> wrote:
Thank you for you help!
Is that in store mode?
No, In store mode Pin 6/11 are -2V
Ahh, the settings need to be the same.
Settings 1 Khz 1 Volt sinewave, CH1 0.5V Timebase 0.1mS
Vert mode: Ch1, XY out, BW in ALT
All the storage out exdept for Menue, Select Wave form and Store.
What did you mean by "(Dependent on T/B and flickering unless you toggle the onscreen display)." and "unless CH1 input is overdriven"
OK, I had the scope in 2 CH, so that is the channel switching signal. With just CH1 on, pins 2/15 are 2Vdc, 4mV replica of input signal using your differential setup on monitor scope. Pins 12/13 5.8V DC, no visible signal using differential setup unless you turn CH1 down to 5mV to overdrive the signal, then you can see it. If you suspect U2101, put a large signal into CH1, turn the CH1 sensitivity down to 5mV and probe pin 15 and then pin13, you should see the signal in and out. No signal out, I would guess U2101 is shot, not uncommon. You could also check Pin21 on U2204, using your settings again, you should see replica 500mV input signal, DC shifted -1V, using the CH1 Y shift you can move the signal up to just above 0V
Am I correct to assume you are looking diferentialy at the 2 signal pairs (Pin 2/15 and 12/13) with another scope on add invert.
David
--- In TekScopes@..., "chipbee40" <chipbee40@> wrote:
Have you checked the position of all the jumpers on the storage board?, a lot of Ebay scopes come with them in diagnostic position.
My U2101 is pt no 234-0408-20 (Later version)
Pin 6/11 of U2101 -1.6V
Settings 1 Khz 1 Volt sinewave, CH1 0.5V Timebase 0.1mS
Pin 2/15 2v DC shifted 2V p/p square wave 4mS period (Dependent on T/B and flickering unless you toggle the onscreen display).
Pin 12/13 5.8VDC, no visible superimposed signal even at 2mV/cm on monitor scope unless CH1 input is overdriven.
I just happen to be working on a 2230, it will be back together shortly so if you need more info make it quick.
JC
--- In TekScopes@..., "david_s5y" <david_s5@> wrote:
I am trying to trouble shoot the missing storage traces. Does anyone have the DC voltage levels for Pin 6 and 11 of a working U2101 (MO36E). I am seeing +5.6 Volts which seems intuitively wrong give the 511 Ohm to -5 Volts.
For that matter with a 1Khz 1V sin wave applied to chan 1 set to .5 V per. What should I see on 2 and 15 and 12 and 13?
Thanks for your help!
David
|
Re: Tek 2230 - Storage does not work.
I just looked at the pictures. Where did you get the 234-0408-20 from?
David
toggle quoted message
Show quoted text
--- In TekScopes@..., David <davidwhess@...> wrote:
Beware that there are two versions of the 2230 storage channel switch
and while they use the same circuit board, there are some discrete
parts changes which need to be made if you replace one with the other.
When I swapped a 234-0408-20, the one with popcorn noise that I posted
about some time ago, with a 155-0022-00 I got uncontrolled
oscillation. I managed to procure a replacement 234-0408-20 instead
of making the changes.
If you measure at pin 21 of the A/D converter, the voltage should be
between about 0.25 and -2.25 volts as you adjust the vertical position
control. If it adjusts within that range and you have no displayed
trace, then the problem is not before this point. I suppose you could
remove R2293 and apply about 1.0 volts directly to the A/D converter
which should generate a vertically centered trace to verify everything
past this point.
On Wed, 25 Jan 2012 17:12:53 -0000, "david_s5y" <david_s5@...>
wrote:
I am trying to trouble shoot the missing storage traces. Does anyone have the DC voltage levels for Pin 6 and 11 of a working U2101 (MO36E). I am seeing +5.6 Volts which seems intuitively wrong give the 511 Ohm to -5 Volts. I measured -2.1 volts in store mode and -1.25 volts in non-store mode
for the 155-0022-00.
I measured -1.62 volts in store mode and -1.11 volts in non-store mode
for the 234-0408-20.
In store mode the voltage changes a bit depending on the channel
selection and alt/chop selection.
+5.6 volts does sound high. Schematic 11 shows the power connections
for the chip on pins 3 and 5 which are not shows on schematic 16. They
should be about 7.4 volts and 1.8 volts although I think it depends a
little bit on which version you have.
For that matter with a 1Khz 1V sin wave applied to chan 1 set to .5 V per. What should I see on 2 and 15 and 12 and 13? I measured about 0.02 volts peak-to-peak to ground at pins 2 or 15
which may seem low but is expected since the impedance is about 50
ohms.
Pins 12 and 13 are the transconductance amplifier outputs into a
cascode so the voltage change there is too small to bother measuring.
I measured about 0.4 volts peak-to-peak at the collector of Q2101.
--- In TekScopes@..., David <davidwhess@> wrote:
The "storage channel switch" is a multiplexor and amplifier IC just
before the digitizer. It is not the storage mode button on the front
of the oscilloscope. I doubt the storage channel switch is the
problem but the vertical signal chain that goes through it should be
checked if the vertical position controls are not the problem.
There are two 4 pin flat cables which carry the channel 1 and channel
2 analog signals to the storage channel switch and if one falls off it
can cause the problem you describe but that would also cause the
readout to be displaced vertically so I do not think that is the
problem.
I never found a 2230 service manual to download. I ended up buying
the Artek Media PDF on CD and it was definately worth the price.
The 2230 that I repaired is pretty much my main oscilloscope.
On Thu, 19 Jan 2012 16:01:46 -0000, "david_s5y" <david_s5@>
wrote:
The trace if off screen in a vertical direction. But it is a flat line and will disappear when moved.
I think you may be onto something with the switch. The scope sat for a long time in high humidity and dust. The traces disappear when I begin to press the switch.
Do you know where I can download the service manual?
David
--- In TekScopes@..., David <davidwhess@> wrote:
I asked about this some time ago and as far as I know, the battery
only backs up the waveform storage which is part of either optional
interface board. None of the various settings persist across power
cycles. You might expect that with the optional battery backed up
memory, the oscilloscope would store its settings there but it does
not.
Is it possible that the trace if off screen in a vertical direction?
That could be a problem with the vertical signal chain through the
storage channel switch or the analog and digital registration
calibration. The vertical position controls are a little weird in
this design since they work in both the analog and digital domains
simultaneously. The oscilloscope reads them to adjust the digital
display to match up with future samples.
If the service manual procedure "Adjust Acquisition Position Offset"
on page 5-11 checks out, then I think the problem will be in the
vertical signal chain leading up to the digitizer.
On Thu, 19 Jan 2012 03:30:04 -0000, "david_s5y" <david_s5@>
wrote:
Sorry to be unclear: By the Acc table I ment the ACQ_MODE_SETUP_TABLE/SELECT_MODE table.
So it is not supposed to persist across power cycles?
The big issues is the missing traces once I press Store. Some times I can move the V positions for the channel and see the trace, but it is a flat line, that soon disappear again.
--- In TekScopes@..., David <davidwhess@> wrote:
Acc Table?
As far as I know, none of the settings are retained when powered down.
There is no calibration data to save either.
You changed the battery on the option card, right? I believe that
only backs up the waveform storage.
On Thu, 19 Jan 2012 03:13:08 -0000, "david_s5y" <david_s5@>
wrote:
I have an Tektronix 2230 Storage scope. Everything appears to work except for the storage.
The unit passes diagnostics. I replaced the NV battery, but it does not remember the Acc Table setting and when switched to Store the traces all disappear (but the display Delta V, time base etc are all there).
Anyone had a similar problem? Any guidance would be appreciated.
David
|
Its actually an encapsulated CR1225 with a couple of 1N4148s - I'm replacing it with a small carrier board with a CR1620 (slightly higher capacity) and the diodes. The Renata 125-1 is not made any more - actually, it hasn't been made for about 20 years. However, a nice lady from Renata rang me today to give me the details of the coin cell used, so a new carrier it is!
Wiring is the same as the Renata 1000-1 -
Nick
|
Re: Tek 2230 - Storage does not work.
Good to know there are two versions. Mine is marked 234-0408B-20.
I have inected signal all the way back to the base of Q2105. From there forward seems to work.
The Pin 6 of the U2101 not being at -1.6 would indicate the part is disabled and since the resiter R1233 is good and the -5Va is correct I am suspectting the U2101.
David
toggle quoted message
Show quoted text
--- In TekScopes@..., David <davidwhess@...> wrote:
Beware that there are two versions of the 2230 storage channel switch
and while they use the same circuit board, there are some discrete
parts changes which need to be made if you replace one with the other.
When I swapped a 234-0408-20, the one with popcorn noise that I posted
about some time ago, with a 155-0022-00 I got uncontrolled
oscillation. I managed to procure a replacement 234-0408-20 instead
of making the changes.
If you measure at pin 21 of the A/D converter, the voltage should be
between about 0.25 and -2.25 volts as you adjust the vertical position
control. If it adjusts within that range and you have no displayed
trace, then the problem is not before this point. I suppose you could
remove R2293 and apply about 1.0 volts directly to the A/D converter
which should generate a vertically centered trace to verify everything
past this point.
On Wed, 25 Jan 2012 17:12:53 -0000, "david_s5y" <david_s5@...>
wrote:
I am trying to trouble shoot the missing storage traces. Does anyone have the DC voltage levels for Pin 6 and 11 of a working U2101 (MO36E). I am seeing +5.6 Volts which seems intuitively wrong give the 511 Ohm to -5 Volts. I measured -2.1 volts in store mode and -1.25 volts in non-store mode
for the 155-0022-00.
I measured -1.62 volts in store mode and -1.11 volts in non-store mode
for the 234-0408-20.
In store mode the voltage changes a bit depending on the channel
selection and alt/chop selection.
+5.6 volts does sound high. Schematic 11 shows the power connections
for the chip on pins 3 and 5 which are not shows on schematic 16. They
should be about 7.4 volts and 1.8 volts although I think it depends a
little bit on which version you have.
For that matter with a 1Khz 1V sin wave applied to chan 1 set to .5 V per. What should I see on 2 and 15 and 12 and 13? I measured about 0.02 volts peak-to-peak to ground at pins 2 or 15
which may seem low but is expected since the impedance is about 50
ohms.
Pins 12 and 13 are the transconductance amplifier outputs into a
cascode so the voltage change there is too small to bother measuring.
I measured about 0.4 volts peak-to-peak at the collector of Q2101.
--- In TekScopes@..., David <davidwhess@> wrote:
The "storage channel switch" is a multiplexor and amplifier IC just
before the digitizer. It is not the storage mode button on the front
of the oscilloscope. I doubt the storage channel switch is the
problem but the vertical signal chain that goes through it should be
checked if the vertical position controls are not the problem.
There are two 4 pin flat cables which carry the channel 1 and channel
2 analog signals to the storage channel switch and if one falls off it
can cause the problem you describe but that would also cause the
readout to be displaced vertically so I do not think that is the
problem.
I never found a 2230 service manual to download. I ended up buying
the Artek Media PDF on CD and it was definately worth the price.
The 2230 that I repaired is pretty much my main oscilloscope.
On Thu, 19 Jan 2012 16:01:46 -0000, "david_s5y" <david_s5@>
wrote:
The trace if off screen in a vertical direction. But it is a flat line and will disappear when moved.
I think you may be onto something with the switch. The scope sat for a long time in high humidity and dust. The traces disappear when I begin to press the switch.
Do you know where I can download the service manual?
David
--- In TekScopes@..., David <davidwhess@> wrote:
I asked about this some time ago and as far as I know, the battery
only backs up the waveform storage which is part of either optional
interface board. None of the various settings persist across power
cycles. You might expect that with the optional battery backed up
memory, the oscilloscope would store its settings there but it does
not.
Is it possible that the trace if off screen in a vertical direction?
That could be a problem with the vertical signal chain through the
storage channel switch or the analog and digital registration
calibration. The vertical position controls are a little weird in
this design since they work in both the analog and digital domains
simultaneously. The oscilloscope reads them to adjust the digital
display to match up with future samples.
If the service manual procedure "Adjust Acquisition Position Offset"
on page 5-11 checks out, then I think the problem will be in the
vertical signal chain leading up to the digitizer.
On Thu, 19 Jan 2012 03:30:04 -0000, "david_s5y" <david_s5@>
wrote:
Sorry to be unclear: By the Acc table I ment the ACQ_MODE_SETUP_TABLE/SELECT_MODE table.
So it is not supposed to persist across power cycles?
The big issues is the missing traces once I press Store. Some times I can move the V positions for the channel and see the trace, but it is a flat line, that soon disappear again.
--- In TekScopes@..., David <davidwhess@> wrote:
Acc Table?
As far as I know, none of the settings are retained when powered down.
There is no calibration data to save either.
You changed the battery on the option card, right? I believe that
only backs up the waveform storage.
On Thu, 19 Jan 2012 03:13:08 -0000, "david_s5y" <david_s5@>
wrote:
I have an Tektronix 2230 Storage scope. Everything appears to work except for the storage.
The unit passes diagnostics. I replaced the NV battery, but it does not remember the Acc Table setting and when switched to Store the traces all disappear (but the display Delta V, time base etc are all there).
Anyone had a similar problem? Any guidance would be appreciated.
David
|
Re: S-30 delta standard and P93C pictures for 130
Hi Fred,
Just found the Data Sheet of the P93C Probe. It is just a piece of 93R Coax with a length of 30 1/2" and a connector. I shall send a scan.
Still searching for the S-30 Delta Standard Manual.
Egge Siert
|
Re: Tek 2230 - Storage does not work.
Beware that there are two versions of the 2230 storage channel switch and while they use the same circuit board, there are some discrete parts changes which need to be made if you replace one with the other. When I swapped a 234-0408-20, the one with popcorn noise that I posted about some time ago, with a 155-0022-00 I got uncontrolled oscillation. I managed to procure a replacement 234-0408-20 instead of making the changes. If you measure at pin 21 of the A/D converter, the voltage should be between about 0.25 and -2.25 volts as you adjust the vertical position control. If it adjusts within that range and you have no displayed trace, then the problem is not before this point. I suppose you could remove R2293 and apply about 1.0 volts directly to the A/D converter which should generate a vertically centered trace to verify everything past this point. On Wed, 25 Jan 2012 17:12:53 -0000, "david_s5y" <david_s5@...> wrote: I am trying to trouble shoot the missing storage traces. Does anyone have the DC voltage levels for Pin 6 and 11 of a working U2101 (MO36E). I am seeing +5.6 Volts which seems intuitively wrong give the 511 Ohm to -5 Volts. I measured -2.1 volts in store mode and -1.25 volts in non-store mode for the 155-0022-00. I measured -1.62 volts in store mode and -1.11 volts in non-store mode for the 234-0408-20. In store mode the voltage changes a bit depending on the channel selection and alt/chop selection. +5.6 volts does sound high. Schematic 11 shows the power connections for the chip on pins 3 and 5 which are not shows on schematic 16. They should be about 7.4 volts and 1.8 volts although I think it depends a little bit on which version you have. For that matter with a 1Khz 1V sin wave applied to chan 1 set to .5 V per. What should I see on 2 and 15 and 12 and 13? I measured about 0.02 volts peak-to-peak to ground at pins 2 or 15 which may seem low but is expected since the impedance is about 50 ohms. Pins 12 and 13 are the transconductance amplifier outputs into a cascode so the voltage change there is too small to bother measuring. I measured about 0.4 volts peak-to-peak at the collector of Q2101. --- In TekScopes@..., David <davidwhess@...> wrote:
The "storage channel switch" is a multiplexor and amplifier IC just
before the digitizer. It is not the storage mode button on the front
of the oscilloscope. I doubt the storage channel switch is the
problem but the vertical signal chain that goes through it should be
checked if the vertical position controls are not the problem.
There are two 4 pin flat cables which carry the channel 1 and channel
2 analog signals to the storage channel switch and if one falls off it
can cause the problem you describe but that would also cause the
readout to be displaced vertically so I do not think that is the
problem.
I never found a 2230 service manual to download. I ended up buying
the Artek Media PDF on CD and it was definately worth the price.
The 2230 that I repaired is pretty much my main oscilloscope.
On Thu, 19 Jan 2012 16:01:46 -0000, "david_s5y" <david_s5@...>
wrote:
The trace if off screen in a vertical direction. But it is a flat line and will disappear when moved.
I think you may be onto something with the switch. The scope sat for a long time in high humidity and dust. The traces disappear when I begin to press the switch.
Do you know where I can download the service manual?
David
--- In TekScopes@..., David <davidwhess@> wrote:
I asked about this some time ago and as far as I know, the battery
only backs up the waveform storage which is part of either optional
interface board. None of the various settings persist across power
cycles. You might expect that with the optional battery backed up
memory, the oscilloscope would store its settings there but it does
not.
Is it possible that the trace if off screen in a vertical direction?
That could be a problem with the vertical signal chain through the
storage channel switch or the analog and digital registration
calibration. The vertical position controls are a little weird in
this design since they work in both the analog and digital domains
simultaneously. The oscilloscope reads them to adjust the digital
display to match up with future samples.
If the service manual procedure "Adjust Acquisition Position Offset"
on page 5-11 checks out, then I think the problem will be in the
vertical signal chain leading up to the digitizer.
On Thu, 19 Jan 2012 03:30:04 -0000, "david_s5y" <david_s5@>
wrote:
Sorry to be unclear: By the Acc table I ment the ACQ_MODE_SETUP_TABLE/SELECT_MODE table.
So it is not supposed to persist across power cycles?
The big issues is the missing traces once I press Store. Some times I can move the V positions for the channel and see the trace, but it is a flat line, that soon disappear again.
--- In TekScopes@..., David <davidwhess@> wrote:
Acc Table?
As far as I know, none of the settings are retained when powered down.
There is no calibration data to save either.
You changed the battery on the option card, right? I believe that
only backs up the waveform storage.
On Thu, 19 Jan 2012 03:13:08 -0000, "david_s5y" <david_s5@>
wrote:
I have an Tektronix 2230 Storage scope. Everything appears to work except for the storage.
The unit passes diagnostics. I replaced the NV battery, but it does not remember the Acc Table setting and when switched to Store the traces all disappear (but the display Delta V, time base etc are all there).
Anyone had a similar problem? Any guidance would be appreciated.
David
|
Re: Tek 2230 - Storage does not work.
Thank you for you help!
Is that in store mode?
Ahh, the settings need to be the same.
Settings 1 Khz 1 Volt sinewave, CH1 0.5V Timebase 0.1mS
Vert mode: Ch1, XY out, BW in ALT
All the storage out exdept for Menue, Select Wave form and Store.
What did you mean by "(Dependent on T/B and flickering unless you toggle the onscreen display)." and "unless CH1 input is overdriven"
Am I correct to assume you are looking diferentialy at the 2 signal pairs (Pin 2/15 and 12/13) with another scope on add invert.
David
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--- In TekScopes@..., "chipbee40" <chipbee40@...> wrote:
Have you checked the position of all the jumpers on the storage board?, a lot of Ebay scopes come with them in diagnostic position.
My U2101 is pt no 234-0408-20 (Later version)
Pin 6/11 of U2101 -1.6V
Settings 1 Khz 1 Volt sinewave, CH1 0.5V Timebase 0.1mS
Pin 2/15 2v DC shifted 2V p/p square wave 4mS period (Dependent on T/B and flickering unless you toggle the onscreen display).
Pin 12/13 5.8VDC, no visible superimposed signal even at 2mV/cm on monitor scope unless CH1 input is overdriven.
I just happen to be working on a 2230, it will be back together shortly so if you need more info make it quick.
JC
--- In TekScopes@..., "david_s5y" <david_s5@> wrote:
I am trying to trouble shoot the missing storage traces. Does anyone have the DC voltage levels for Pin 6 and 11 of a working U2101 (MO36E). I am seeing +5.6 Volts which seems intuitively wrong give the 511 Ohm to -5 Volts.
For that matter with a 1Khz 1V sin wave applied to chan 1 set to .5 V per. What should I see on 2 and 15 and 12 and 13?
Thanks for your help!
David
|
Re: Tek 2230 - Storage does not work.
Have you checked the position of all the jumpers on the storage board?, a lot of Ebay scopes come with them in diagnostic position.
My U2101 is pt no 234-0408-20 (Later version)
Pin 6/11 of U2101 -1.6V
Settings 1 Khz 1 Volt sinewave, CH1 0.5V Timebase 0.1mS
Pin 2/15 2v DC shifted 2V p/p square wave 4mS period (Dependent on T/B and flickering unless you toggle the onscreen display).
Pin 12/13 5.8VDC, no visible superimposed signal even at 2mV/cm on monitor scope unless CH1 input is overdriven.
I just happen to be working on a 2230, it will be back together shortly so if you need more info make it quick.
JC
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Show quoted text
--- In TekScopes@..., "david_s5y" <david_s5@...> wrote:
I am trying to trouble shoot the missing storage traces. Does anyone have the DC voltage levels for Pin 6 and 11 of a working U2101 (MO36E). I am seeing +5.6 Volts which seems intuitively wrong give the 511 Ohm to -5 Volts.
For that matter with a 1Khz 1V sin wave applied to chan 1 set to .5 V per. What should I see on 2 and 15 and 12 and 13?
Thanks for your help!
David
|
Re: 155-0242-01: Hybrid decapsulated
Very nice work, Jose. Any idea what the chips are?
?
Keep up the great work.
?
?
Tom
?
?
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Show quoted text
----- Original Message -----
Sent: Wednesday, January 25, 2012 9:37
AM
Subject: [TekScopes] Re: 155-0242-01:
Hybrid decapsulated
?
I published two photos from the those 3 silicon chips inside. One
driver, two similar power amps. Will try to get bigger magnification, localize
the failure...
Cheers! CT1DGN
The LINK:
---
In TekScopes@...,
Jerry Massengale >
>
>
Jose,
>
> Great pics. Thank you.
>
> jerry
>
>
>
>
>
>
> Jerry Massengale
>
jmassen418a@...
>
>
>
>
> -----Original
Message-----
> From: viagioz
> To: TekScopes
<TekScopes@...>
>
Sent: Fri, Dec 16, 2011 9:08 am
> Subject: [TekScopes] 155-0242-01:
Hybrid X-Ray Photos
>
>
>
>
> HI
frinds,
>
> I share with you the inside from TEK24xx Z Axis
Hybrid:
>
>
>
> At this level investigation everything seems to be OK inside (the 3
die attach, bounding...)
>
> It is related with the subject
"2465B no trace".
>
> I try now to borrow an hybrid to be sure
it is the source of the problem.
>
> Then I will remove the
ceramic attached underneath and I will share with you microscope
pictures.
>
> Nice weekend, maybe Merry Christmas! I will not get
the new hybrid before next year, I guess!
>
> 73'
>
> Jose
> CT1DGN
>
|
Re: Tek 2230 - Storage does not work.
I am trying to trouble shoot the missing storage traces. Does anyone have the DC voltage levels for Pin 6 and 11 of a working U2101 (MO36E). I am seeing +5.6 Volts which seems intuitively wrong give the 511 Ohm to -5 Volts.
For that matter with a 1Khz 1V sin wave applied to chan 1 set to .5 V per. What should I see on 2 and 15 and 12 and 13?
Thanks for your help!
David
toggle quoted message
Show quoted text
--- In TekScopes@..., David <davidwhess@...> wrote:
The "storage channel switch" is a multiplexor and amplifier IC just
before the digitizer. It is not the storage mode button on the front
of the oscilloscope. I doubt the storage channel switch is the
problem but the vertical signal chain that goes through it should be
checked if the vertical position controls are not the problem.
There are two 4 pin flat cables which carry the channel 1 and channel
2 analog signals to the storage channel switch and if one falls off it
can cause the problem you describe but that would also cause the
readout to be displaced vertically so I do not think that is the
problem.
I never found a 2230 service manual to download. I ended up buying
the Artek Media PDF on CD and it was definately worth the price.
The 2230 that I repaired is pretty much my main oscilloscope.
On Thu, 19 Jan 2012 16:01:46 -0000, "david_s5y" <david_s5@...>
wrote:
The trace if off screen in a vertical direction. But it is a flat line and will disappear when moved.
I think you may be onto something with the switch. The scope sat for a long time in high humidity and dust. The traces disappear when I begin to press the switch.
Do you know where I can download the service manual?
David
--- In TekScopes@..., David <davidwhess@> wrote:
I asked about this some time ago and as far as I know, the battery
only backs up the waveform storage which is part of either optional
interface board. None of the various settings persist across power
cycles. You might expect that with the optional battery backed up
memory, the oscilloscope would store its settings there but it does
not.
Is it possible that the trace if off screen in a vertical direction?
That could be a problem with the vertical signal chain through the
storage channel switch or the analog and digital registration
calibration. The vertical position controls are a little weird in
this design since they work in both the analog and digital domains
simultaneously. The oscilloscope reads them to adjust the digital
display to match up with future samples.
If the service manual procedure "Adjust Acquisition Position Offset"
on page 5-11 checks out, then I think the problem will be in the
vertical signal chain leading up to the digitizer.
On Thu, 19 Jan 2012 03:30:04 -0000, "david_s5y" <david_s5@>
wrote:
Sorry to be unclear: By the Acc table I ment the ACQ_MODE_SETUP_TABLE/SELECT_MODE table.
So it is not supposed to persist across power cycles?
The big issues is the missing traces once I press Store. Some times I can move the V positions for the channel and see the trace, but it is a flat line, that soon disappear again.
--- In TekScopes@..., David <davidwhess@> wrote:
Acc Table?
As far as I know, none of the settings are retained when powered down.
There is no calibration data to save either.
You changed the battery on the option card, right? I believe that
only backs up the waveform storage.
On Thu, 19 Jan 2012 03:13:08 -0000, "david_s5y" <david_s5@>
wrote:
I have an Tektronix 2230 Storage scope. Everything appears to work except for the storage.
The unit passes diagnostics. I replaced the NV battery, but it does not remember the Acc Table setting and when switched to Store the traces all disappear (but the display Delta V, time base etc are all there).
Anyone had a similar problem? Any guidance would be appreciated.
David
|
Re: Aluminum panels wanted
Thanks Guys. I have panels coming on a trade deal.
Jerry Massengale
jmassen418a@...
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Show quoted text
-----Original Message-----
From: Chris Moore
To: TekScopes
Sent: Wed, Jan 25, 2012 5:34 am
Subject: Re: [TekScopes] Re: Aluminum panels wanted
?
Hi Jerry,
Why couldn't you use a blank electrical box cover from lowes hardware? Cut to size of course.
Chris
--- On Wed, 1/25/12, Jerry Massengale <jmassen418a@...> wrote:
From: Jerry Massengale <jmassen418a@...>
Subject: Re: [TekScopes] Re: Aluminum panels wanted
To: TekScopes@...
Date: Wednesday, January 25, 2012, 4:03 PM
?
Hi,
I know what you are talking about. I have a couple but want something cheaper for resale. Thanks.
jerry
-----Original Message-----
From: Heinz-Peter Deutsch < hpdeutsch@...>
To: TekScopes < TekScopes@...>
Sent: Wed, Jan 25, 2012 4:39 am
Subject: [TekScopes] Re: Aluminum panels wanted
?
Tek No 016-0155-00
----------------------------------------------
What are blind panels? Where do you get them?
Jerry Massengale
jmassen418a@...
--
Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir
belohnen Sie mit bis zu 50,- Euro!
|
|
Re: Aluminum panels wanted
Hi Jerry,
Why couldn't you use a blank electrical box cover from lowes hardware? Cut to size of course.
Chris
|
--- On Wed, 1/25/12, Jerry Massengale wrote:
From: Jerry Massengale
Subject: Re: [TekScopes] Re: Aluminum panels wanted
To: TekScopes@...
Date: Wednesday, January 25, 2012, 4:03 PM
?
Hi,
I know what you are talking about. I have a couple but want something cheaper for resale. Thanks.
jerry
Jerry Massengale
jmassen418a@...
-----Original Message-----
From: Heinz-Peter Deutsch
To: TekScopes
Sent: Wed, Jan 25, 2012 4:39 am
Subject: [TekScopes] Re: Aluminum panels wanted
?
Tek No 016-0155-00
----------------------------------------------
What are blind panels? Where do you get them?
Jerry Massengale
jmassen418a@...
--
Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir
belohnen Sie mit bis zu 50,- Euro!
|
Re: Power supply problem with Tek 2220
Tektronix 2230, identical to 2220, less a few switch options, working, voltage across R907 0.23Volts
JC
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Show quoted text
--- In TekScopes@..., "Tan Chor Ming" <jonray03@...> wrote:
Hi Tom,
Thank you for the detail of the problem which is similar to my tek 2220.
I am still unable to nail down the problem. I believe the scope is working
normally, because when it fires up it works normally.
My feeling is that it poorly designed thermally for 230V operation
Do you have voltage measurement for tek 2235 on R907?
I am getting 0.198V (with the +5V to the storage board disconnected,
effectively turning off the storage function).
This means that without the storage function connection, the current on +43V
is slightly below 1A.
I am not sure if this is a normal condition but it should be similar to the
tek 2235.
Under this condition, the scope could operate for quite a while without
problem
Once the +5V is connected to the storage board, voltage at R907 goes up to
2.3V~2.5V or about 1.15 to 1.25A on +43 and the power supply will shut down.
Following done with little effect or improvement
- Change 3 filter caps (only those that are feels hot) - C960, C962, C964
(for -5V for 2220 only)
- Change NMOS P9070. When changing P9070, I used a separate heatsink for
P9070 and still such down happens which means it is unlikely to be caused by
the thermal shutdown board.
- Shutdown is more likely cause by spurious overload in R907
- Change C907
- Change CR907 (two diode in parallel)
- Added C919 with 1000pf in parallel. Lowered switching freq but still
having a heated P9070 which shuts down. Not sure what freq but it is
definitely audible.
Rgds,
Chor Ming
_____
From: TekScopes@... [mailto:TekScopes@...] On Behalf
Of tom jobe
Sent: Monday, January 23, 2012 11:17 PM
To: TekScopes@...
Subject: Re: [TekScopes] Re: Power supply problem with Tek 2220
|
Re: Aluminum panels wanted
On 01/25/2012 10:03 AM, Jerry Massengale wrote: Tek No 016-0155-00 Hi,
I know what you are talking about. I have a couple but want something cheaper for resale. Thanks. You mentioned polycarbonate could do. What about specifying a laser cutting pattern to make them instead of buying them?
|
David Hess