When the EHT transformer is connected to the 25kHz HV drive, then pin 13 on the control IC hits 0V pretty much immediately after the inverter starts causing a shutdown after 10mS. Anything below +50mV on this pin indicates a fault condition (inverter current > 5A).
I tried disconnecting the HV Multiplier, but that wasn't the problem. My suspicion is shorted turns in the EHT transformer.
With the EHT transformer disconnected the supply also ticks, but not because of over-current, but because Bal-Sense (pin 2) is just over +200mV when the 10mS timer expires. From what others have said this is pretty much normal behaviour.
Ho-Hum
Who needs some 7834 spares (including a working PSU)?
Dave
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Re: Help with 465 repair - no signal on 50mv/100mv/200mv ranges
The fingers are gold plated and looked very clean before I IPA'd them. Is there anything else in the circuit that could be causing the problem? Here is the relevant page from the service manual: /g/TekScopes/album?id=86337
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Re: still trying to track down 2216 manuals
Thanks for the help, all. I have a lead on the 2216 service manual. The 2216 operators manual is at the vintage tek museum website. It will be interesting to see how much the 2212 and the 2216 have in common. Cheers, bill
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Re: Help with 465 repair - no signal on 50mv/100mv/200mv ranges
Fair enough -if the contacts are gold then there won't be corrosion and IPA
is just fine.
I've wrestled with lots of silver plated tube sockets and connectors and
there Deoxit and NevrDull are really helpful
Don
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On Wed, Mar 6, 2019 at 10:58 AM n4buq <n4buq@...> wrote: I may be wrong, but if this is in regards to the attenuator fingers, I
think they're gold plated so no corrosion should be present and only
cleaning with IPA is necessary/recommended.
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Don A" <don.asquin@...>
To: [email protected]
Sent: Wednesday, March 6, 2019 9:34:10 AM
Subject: Re: [TekScopes] Help with 465 repair - no signal on 50mv/100mv/200mv ranges
If you need to clean switches I don't find Isopropyl Alcohol (IPA)does a
great job. I use the Deoxit products from CAIG.
They have products for cleaning switches Deoxit D series and products for
cleaning potentiometers the Deoxit Fader series.
To me, the problem with IPA is that it is a solvent that cleans grease
but
won't remove tarnish. Deoxit D series will. For very tarnished surfaces (say
tube sockets or connector pins) I use a product called Nevr Dull
This a very fine polish that works great.
Yes, these product are expensive but the last a very long time for many
projects.
My thoughts
Don
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Re: Help with 465 repair - no signal on 50mv/100mv/200mv ranges
I may be wrong, but if this is in regards to the attenuator fingers, I think they're gold plated so no corrosion should be present and only cleaning with IPA is necessary/recommended.
Thanks,
Barry - N4BUQ
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Show quoted text
----- Original Message ----- From: "Don A" <don.asquin@...>
To: [email protected]
Sent: Wednesday, March 6, 2019 9:34:10 AM
Subject: Re: [TekScopes] Help with 465 repair - no signal on 50mv/100mv/200mv ranges
If you need to clean switches I don't find Isopropyl Alcohol (IPA)does a
great job. I use the Deoxit products from CAIG.
They have products for cleaning switches Deoxit D series and products for
cleaning potentiometers the Deoxit Fader series.
To me, the problem with IPA is that it is a solvent that cleans grease but
won't remove tarnish. Deoxit D series will. For very tarnished surfaces (say
tube sockets or connector pins) I use a product called Nevr Dull
This a very fine polish that works great.
Yes, these product are expensive but the last a very long time for many
projects.
My thoughts
Don
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Let us all know how that turns out
that one for $55 looked very clean at first glance
Hi, when I got the 7B15, it looked very clean and had no shorts, but no function as well.
After a "quart" of IPA, I got some life out of it, but no full size traces. I removed the hybrid and cleaned the socket, pcb, and the the hybrid pads and, bingo,
the whole thing worked.
So, I would describe the experience as positive, we can not expect to get 100% working unit for $59. I believe it worked when it was decommissioned, but corroded while being stored.
Now my 7104 is complete: 2x7A29, 7B15 and 7B10, I am very happy!!!
--
Cheers,
Fred S.
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Re: Help with 465 repair - no signal on 50mv/100mv/200mv ranges
Hi, just clean the contacs of the input attenuator with IPA. There is a video on youtube showing how to clean them on a Tek 485, but that procedure is absolutely the same.
--
Best regards,
Fred S.
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Re: Help with 465 repair - no signal on 50mv/100mv/200mv ranges
If you need to clean switches I don't find Isopropyl Alcohol (IPA)does a great job. I use the Deoxit products from CAIG.
They have products for cleaning switches Deoxit D series and products for cleaning potentiometers the Deoxit Fader series.
To me, the problem with IPA is that it is a solvent that cleans grease but won't remove tarnish. Deoxit D series will. For very tarnished surfaces (say tube sockets or connector pins) I use a product called Nevr Dull This a very fine polish that works great.
Yes, these product are expensive but the last a very long time for many projects.
My thoughts
Don
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Re: still trying to track down 2216 manuals
Hey Bill,
you might try to ping the Vintage Tek museum folks and see whether they
have the service manual on fiche. There's a tentative index of the
instruments covered in this posting:
, which does have the 2212, but it
doesn't say whether this includes the service manual.
Siggi
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On Mon, Mar 4, 2019 at 3:02 PM bill K7WXW <K7WXW@...> wrote: I've search through the archives here and saw the 2014(?) discussion on
the 2216 service manual. I have copies of the partial manuals for the 2216
and 2212. Alas, no schematics. Yet.
I am surmising that the manuals' unavailability is related to the fact
that both the 2212 and the 2216 were designed in Heerenveen. I would guess
that they were only manufactured in Holland and repaired at the Benelux
Repair Center. Since Benelux was closed in 2000 as part of the Tek breakup,
who knows what happened to the stock of manuals? I am hoping that they all
didn't end up in the tip.
Unfortunately, I am now in "dog chasing bone" mode now wrt to finding
documentation. Does anyone know if there's a European-based Tek fan or
alumni club? I want to see if I can track down anyone that worked in
Benelux. So as not to inflict my obsession on others, I can be contacted
off list, my call sign at arrl dot net.
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Caig fader lube had a name change to deoxit fader lube a few years back. Terrific product designed specifically for this task. There also a product for cleaning switch contacts deoxit D5. Also fantastic. Yup you will pay a few bucks for a can but they last forever through countless projects. My thoughts Don On Wed., Mar. 6, 2019, 12:20 a.m. Frank DuVal via Groups.Io, <corvairduval= [email protected]> wrote: I hope you mean brake cleaner, as brake fluid comes in two types,
neither of which seem good for inside of potentiometers.... one Glycol
based and the other a synthetic base both with a viscosity greater than
water.
Yes, brake cleaner is very aggressive, just like carburetor cleaner. I
would not use it around plastic until I tried it on a sample disposable
part.
Cleaning tuners and volume controls was standard service back 30 years
ago. Many spray chemicals for the job. Using that little red straw got
the cleaner into the pot well.
But, using that spray on fader controls rendered them bad instantly! Not
a great lesson to be learned by trying.
Another vote for DeOxit (Caig) Fader cleaner.
Frank DuVal
On 3/5/2019 9:02 PM, Bob Albert via Groups.Io wrote:
I think Brake fluid is potent as well and I wouldn't use it on anything without the utmost care.
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Re: still trying to track down 2216 manuals
Jim,
My post was relating to Bill K7WXW's earlier post (see below). I don't own a 2216; I was just trying to help. I don't know if your suggestion has possibilities or not....
Colin.
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Jim Olson Sent: 05 March 2019 20:18 To: [email protected]; Colin Herbert via Groups.Io Subject: Re: [TekScopes] still trying to track down 2216 manuals Colin, have you tried the Vintage TEK Museum in Beaverton Oregon? they have a good collection of original Tek manuals. Jim O On March 5, 2019 at 10:42 AM "Colin Herbert via Groups.Io" <colingherbert@... mailto:colingherbert@... > wrote:
I don't know whether this is at all valid, but after doing a bit of searching with Bing, I found this:
It claims to be Tektronix 2216, 4 Channel digital Storage Oscilloscope Service Manual for $20 and is 332 pages. Oddly, they state that the Operator's Manual is "Not Available" which we know is untrue. Since the User Manual is 328 pages, I'm inclined to think it is that.
Is it worth a punt?
Colin.
-----Original Message-----
From: [email protected] mailto:[email protected] [mailto:[email protected] mailto:[email protected] ] On Behalf Of bill K7WXW
Sent: 04 March 2019 20:03
To: [email protected] mailto:[email protected]
Subject: [TekScopes] still trying to track down 2216 manuals
I've search through the archives here and saw the 2014(?) discussion on the 2216 service manual. I have copies of the partial manuals for the 2216 and 2212. Alas, no schematics. Yet.
I am surmising that the manuals' unavailability is related to the fact that both the 2212 and the 2216 were designed in Heerenveen. I would guess that they were only manufactured in Holland and repaired at the Benelux Repair Center. Since Benelux was closed in 2000 as part of the Tek breakup, who knows what happened to the stock of manuals? I am hoping that they all didn't end up in the tip.
Unfortunately, I am now in "dog chasing bone" mode now wrt to finding documentation. Does anyone know if there's a European-based Tek fan or alumni club? I want to see if I can track down anyone that worked in Benelux. So as not to inflict my obsession on others, I can be contacted off list, my call sign at arrl dot net.
|
Re: Tektronix TDS400/500/600/TLS216 displays and drivers
Hello Ingo,
while I do not know to 100 percent, I think they should be compatible. Afaik, the color Palette of the DPO / InstaVue actually is quite limited - Danaher accomplished the trick via Palette Stunts similar to the Palm IIIC.
Tam
---
With best regards
Tam HANNA (emailing on a BlackBerry PRIV)
Enjoy electronics? Join 14k other followers by visiting the Crazy Electronics Lab at
|
Help with 465 repair - no signal on 50mv/100mv/200mv ranges
Hi all, I am trying to get my 465 scope repaired. CH2 has a problem where I get a flat-line (with some noise - signal is the calibration square wave) when set to the 50mv/100mv/200mv ranges. This is obviously related to the #6/#10 volts/div rotors and related circuitry. I have taken the scope apart to clean the fingers (using the suggested paper soaked in IPA,) and I also re-soldered some suspect joints. However, putting it all back together did not fix the problem. I also swapped the 10x capacitor modules between channels, but that did not change anything either.
Suggestions? Thanks for the help!
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
I hope you mean brake cleaner, as brake fluid comes in two types, neither of which seem good for inside of potentiometers....? one Glycol based and the other a synthetic base both with a viscosity greater than water.
Yes, brake cleaner is very aggressive, just like carburetor cleaner. I would not use it around plastic until I tried it on a sample disposable part.
Cleaning tuners and volume controls was standard service back 30 years ago. Many spray chemicals for the job. Using that little red straw got the cleaner into the pot well.
But, using that spray on fader controls rendered them bad instantly! Not a great lesson to be learned by trying.
Another vote for DeOxit (Caig) Fader cleaner.
Frank DuVal
toggle quoted message
Show quoted text
On 3/5/2019 9:02 PM, Bob Albert via Groups.Io wrote: I think ? Brake fluid is potent as well and I wouldn't use it on anything without the utmost care.
|
Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
I rocked the horizontal and vertical controls until my fingers and wrist got sore while passing the time with some EEV blog videos, problem resolved and the stickiness has gone away, thanks for all the help!
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
A better cleaner for pots is Caig Faderlube. It has a little lubricant in it and will not attack the resistance strips. Also works on wire wound pots.
Another place to get dry IPA is at a computer store or department. They usually have 99+% in either bottles or spray cans. IPA absorbs moisture until it becomes 91% which is why its not usually stocked in the dry form. Dry IPA will become 91% if exposed to the air for very long. I think the spray can version probably stays dry for longer than the bottled kind.
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On 3/5/2019 5:28 PM, Bill Carns wrote: If you go to a pharmacy and talk with the Pharmacist, they can give you IPA with a higher percent IPA and less water. This is better for pots, but be careful to not saturate. Sometimes you can damage the carbon resistance layer that is laid down for the wiper to run on. I am not sure if that is true for the ones TEK uses.
Bill
--
Richard Knoppow
dickburk@...
WB6KBL
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Another vote for Deoxit products, always had good experiences with them.
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Deoxit D5 or DN5 followed by fader lube is what I do. The D5 gives it a good washout and the fader lube adds some lube hence the lube part of the name.
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On Tue, Mar 5, 2019 at 07:56 PM, Bill Carns wrote:
Well, the danger there is if it is dying from deterioration of the element,
then that will only make it worse.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of
wilson2115@...
Sent: Tuesday, March 05, 2019 7:41 PM
To: [email protected]
Subject: Re: [TekScopes] 91% Isopropyl Rubbing Alcohol to clean
potentiometers?
Thanks, I will check into that. Ideally, what would be the best solution I
should use. Perhaps maybe I could run the pots back and forth about 500 times.
|
I am in central Arkansas about 75 miles NNE of Little Rock. Pretty much the middle of nowhere. That's the good part and the bad part.
Color display is a non-issue. I care about the DAQ and repairability.
I just received a 100 pS spike generator from Leo Bodnar. it's a modified version of his 40 pS rise time square wave generator. Absolutely awesome!
It's very close to a minimum phase Gaussian pulse. I don't know what sampling head he is using on his CSA803 (I've asked), but I suspect that it is not an SD30 or SD32 from the appearance of the trailing edge in the plots that came with the unit. If it's an SD24 or SD26 he's banging up against the BW of the sampling head. This thing is *fast*! I now have both the square wave and the impulse versions. If you are trying to test and calibrate scopes, you need a pair. They are an incredible bargain relative to anything else I know of.
In oil industry seismic work, the standard way of testing the AFE and ADC is to input an impulse. Nyquist is typically 250 Hz, so it's very easy to generate a clean impulse. With that recorded on tape before you start acquiring data it's very easy to fix any issues during processing. And spot that it's too broken to use until fixed. Normal processing practice is to zero phase the data which is not physical, but it's a lot easier for the seismic interpreter to pick the time of a symmetric waveform.
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Well, the danger there is if it is dying from deterioration of the element, then that will only make it worse.
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Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of wilson2115@... Sent: Tuesday, March 05, 2019 7:41 PM To: [email protected]Subject: Re: [TekScopes] 91% Isopropyl Rubbing Alcohol to clean potentiometers? Thanks, I will check into that. Ideally, what would be the best solution I should use. Perhaps maybe I could run the pots back and forth about 500 times.
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David C. Partridge
bill K7WXW
Fred S.
Jared Cabot