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

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

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

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

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

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

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

--- 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

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.

?

?

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