Re: TDS3032 Will not Finish Bootup
¡°Well, I would not know. Hope it works. Just a warning, some of these distributors that sell military surplus will make you swear you won't resell or ship them to enemies of the free world! I had to fill in a form, sign it and send it back before they shipped¡± Hello Mark, are you talking that Nac store? I just selected one of the chips for $36 ( I think I said $38 in an earlier response ), and have them a PayPal payment. Web site said it will ship tomorrow. Do, I guess we¡¯ll see. I did not know it was military surplus. At least if it works, I won¡¯t be as afraid to dremmal in to the old chip to try and find the battery to wire to. Dave On Mon, Nov 19, 2018 at 9:35 PM Mark Goldberg <marklgoldberg@...> wrote: Well, I would not know. Hope it works. Just a warning, some of these
distributors that sell military surplus will make you swear you won't
resell or ship them to enemies of the free world! I had to fill in a form,
sign it and send it back before they shipped. Pricing is a crapshoot with
these places too. Negotiate as best you can.
Regards,
Mark
On Mon, Nov 19, 2018 at 7:15 PM David Kuhn <Daveyk021@...> wrote:
¡°part says Green Tree Electronics has them:¡°
Those Maxim parts and not Dallas. I¡¯m sure it¡¯s not high speed and should
work in place of the Dallas.
Dave
On Mon, Nov 19, 2018 at 9:08 PM Daveyk021 <daveyk021@...> wrote:
¡°don't know though if it will boot with blank or corrupted RAM chip but it
could be
worth a try.¡°
Thank you for the suggestion Haken. I did try that with the ¡°new¡± battram
with no response.
Dave
On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@... wrote:
On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
Nac in Florida had 28 of them left. I bought two marked dallas semi
from
them a few weeks ago. Counterfeit or not they worked for me
On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier
on
EBAY,
Octopart says Green Tree Electronics has them:
Green Tree claims to check obsolete parts for counterfeits. I have not
bought from them but have bought from other similar distributors.
Lately,
any "new" parts from eBay or Amazon or from non distributors have been
fakes, so I stopped getting parts from those sources.
Regards,
Mark
|
Re: TDS3032 Will not Finish Bootup
¡°
Don¡¯t faint when you see the price. I use a tl866-II plus to read and write
these if it were the ds1230 series I have a few subs for them one is a smd
on a card with ext. battery connects¡±
I ordered one from their web site, about $39/$4 fedex ground shipping.
I think, I¡¯ll solder lead carriers in when I pull the old chip again. I
doubt I would have a proper sized socket. I used to love those gold lead
carriers; although it may be hard to keep them all straight.
Dave
toggle quoted message
Show quoted text
On Mon, Nov 19, 2018 at 9:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
Don¡¯t faint when you see the price. I use a tl866-II plus to read and
write these if it were the ds1230 series I have a few subs for them one is
a smd on a card with ext. battery connects
Sent from Mail for Windows 10
From: David Kuhn
Sent: Monday, November 19, 2018 9:15 PM
To: [email protected]
Subject: Re: [TekScopes] TDS3032 Will not Finish Bootup
¡°part says Green Tree Electronics has them:¡°
Those Maxim parts and not Dallas. I¡¯m sure it¡¯s not high speed and should
work in place of the Dallas.
Dave
On Mon, Nov 19, 2018 at 9:08 PM Daveyk021 <daveyk021@...> wrote:
¡°don't know though if it will boot with blank or corrupted RAM chip but it
could be
worth a try.¡°
Thank you for the suggestion Haken. I did try that with the ¡°new¡± battram
with no response.
Dave
On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@...>
wrote:
On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
Nac in Florida had 28 of them left. I bought two marked dallas semi
from
them a few weeks ago. Counterfeit or not they worked for me
On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
Octopart says Green Tree Electronics has them:
Green Tree claims to check obsolete parts for counterfeits. I have not
bought from them but have bought from other similar distributors.
Lately,
any "new" parts from eBay or Amazon or from non distributors have been
fakes, so I stopped getting parts from those sources.
Regards,
Mark
---
This email has been checked for viruses by AVG.
|
Re: 475 Comment/Question & Minor Reference To 465B
Hi,
I looked up the Tek part number 151-0271-00 in the Common Design Parts catalog from Tek, and found a number of cross references. The first JEDEC was the A5T4261, and the 2N4261. Unfortunately, NONE are stocked at Digikey, Avnet, or any other distributor, including Jameco. However, I did find the datasheet for the A5T4261 at . If interested, the crossreferences can be found at has a list of catalogs, and the one where I found the majority of info is at . It is titled Integrated Circuits, but contains LOTS of other semiconductors as well. contains a list of part numbers, and all equipment and locations they are found. This one indicates a JEDEC of SPS8236. If all else fails, you might find a transistor in another piece of equipment from that list, and use it.
Good luck!
|
Re: TDS3032 Will not Finish Bootup
Well, I would not know. Hope it works. Just a warning, some of these
distributors that sell military surplus will make you swear you won't
resell or ship them to enemies of the free world! I had to fill in a form,
sign it and send it back before they shipped. Pricing is a crapshoot with
these places too. Negotiate as best you can.
Regards,
Mark
toggle quoted message
Show quoted text
On Mon, Nov 19, 2018 at 7:15 PM David Kuhn <Daveyk021@...> wrote: ¡°part says Green Tree Electronics has them:¡°
Those Maxim parts and not Dallas. I¡¯m sure it¡¯s not high speed and should
work in place of the Dallas.
Dave
On Mon, Nov 19, 2018 at 9:08 PM Daveyk021 <daveyk021@...> wrote:
¡°don't know though if it will boot with blank or corrupted RAM chip but it
could be
worth a try.¡°
Thank you for the suggestion Haken. I did try that with the ¡°new¡± battram
with no response.
Dave
On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@...>
wrote:
On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
Nac in Florida had 28 of them left. I bought two marked dallas semi
from
them a few weeks ago. Counterfeit or not they worked for me
On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
Octopart says Green Tree Electronics has them:
Green Tree claims to check obsolete parts for counterfeits. I have not
bought from them but have bought from other similar distributors.
Lately,
any "new" parts from eBay or Amazon or from non distributors have been
fakes, so I stopped getting parts from those sources.
Regards,
Mark
|
Re: TDS3032 Will not Finish Bootup
Don¡¯t faint when you see the price. I use a tl866-II plus to read and write these if it were the ds1230 series I have a few subs for them one is a smd on a card with ext. battery connects Sent from Mail for Windows 10 From: David Kuhn Sent: Monday, November 19, 2018 9:15 PM To: [email protected]Subject: Re: [TekScopes] TDS3032 Will not Finish Bootup ¡°part says Green Tree Electronics has them:¡° Those Maxim parts and not Dallas. I¡¯m sure it¡¯s not high speed and should work in place of the Dallas. Dave On Mon, Nov 19, 2018 at 9:08 PM Daveyk021 <daveyk021@...> wrote: ¡°don't know though if it will boot with blank or corrupted RAM chip but it
could be
worth a try.¡°
Thank you for the suggestion Haken. I did try that with the ¡°new¡± battram
with no response.
Dave
On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@...>
wrote:
On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
Nac in Florida had 28 of them left. I bought two marked dallas semi from
them a few weeks ago. Counterfeit or not they worked for me
On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
Octopart says Green Tree Electronics has them:
Green Tree claims to check obsolete parts for counterfeits. I have not
bought from them but have bought from other similar distributors. Lately,
any "new" parts from eBay or Amazon or from non distributors have been
fakes, so I stopped getting parts from those sources.
Regards,
Mark
--- This email has been checked for viruses by AVG.
|
Re: TDS3032 Will not Finish Bootup
Well, Maxim bought Dallas Semiconductor some years ago, IIRC.Jim FSent from my Verizon, Samsung Galaxy smartphone
toggle quoted message
Show quoted text
-------- Original message --------From: David Kuhn <Daveyk021@...> Date: 11/19/18 6:14 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] TDS3032 Will not Finish Bootup ¡°part says Green Tree Electronics has them:¡°Those Maxim parts and not Dallas. I¡¯m sure it¡¯s not high speed and shouldwork in place of the Dallas.DaveOn Mon, Nov 19, 2018 at 9:08 PM Daveyk021 <daveyk021@...> wrote:> ¡°don't know though if it will boot with blank or corrupted RAM chip but it> could be> worth a try.¡°>> Thank you for the suggestion Haken. I did try that with the ¡°new¡± battram> with no response.>> Dave>> On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@...>> wrote:>>> On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:>>>> > Nac in Florida had 28 of them left. I bought two marked dallas semi from>> > them a few weeks ago. Counterfeit or not they worked for me>> > > On 11/19/18 5:09 PM, David Kuhn wrote:>> > > > Is the new Chinese DS1742W-150 bad?? There is only one supplier on>> > EBAY,>> >>> >>> Octopart says Green Tree Electronics has them:>>>> >>>> >>>> Green Tree claims to check obsolete parts for counterfeits. I have not>> bought from them but have bought from other similar distributors. Lately,>> any "new" parts from eBay or Amazon or from non distributors have been>> fakes, so I stopped getting parts from those sources.>>>> Regards,>>>> Mark>>>> >>>>
|
Re: TDS3032 Will not Finish Bootup
¡°part says Green Tree Electronics has them:¡°
Those Maxim parts and not Dallas. I¡¯m sure it¡¯s not high speed and should
work in place of the Dallas.
Dave
toggle quoted message
Show quoted text
On Mon, Nov 19, 2018 at 9:08 PM Daveyk021 <daveyk021@...> wrote: ¡°don't know though if it will boot with blank or corrupted RAM chip but it
could be
worth a try.¡°
Thank you for the suggestion Haken. I did try that with the ¡°new¡± battram
with no response.
Dave
On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@...>
wrote:
On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
Nac in Florida had 28 of them left. I bought two marked dallas semi from
them a few weeks ago. Counterfeit or not they worked for me
On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
Octopart says Green Tree Electronics has them:
Green Tree claims to check obsolete parts for counterfeits. I have not
bought from them but have bought from other similar distributors. Lately,
any "new" parts from eBay or Amazon or from non distributors have been
fakes, so I stopped getting parts from those sources.
Regards,
Mark
|
Re: TDS3032 Will not Finish Bootup
¡° Green Tree claims to check obsolete parts for counterfeits. I have not bought from them but have¡° Thank you Mark. I just put in an RFQ with them. Dave On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@...> wrote: On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
Nac in Florida had 28 of them left. I bought two marked dallas semi from
them a few weeks ago. Counterfeit or not they worked for me
On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
Octopart says Green Tree Electronics has them:
Green Tree claims to check obsolete parts for counterfeits. I have not
bought from them but have bought from other similar distributors. Lately,
any "new" parts from eBay or Amazon or from non distributors have been
fakes, so I stopped getting parts from those sources.
Regards,
Mark
|
Re: TDS3032 Will not Finish Bootup
¡°don't know though if it will boot with blank or corrupted RAM chip but it could be worth a try.¡° Thank you for the suggestion Haken. I did try that with the ¡°new¡± battram with no response. Dave On Mon, Nov 19, 2018 at 8:42 PM Mark Goldberg <marklgoldberg@...> wrote: On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote:
Nac in Florida had 28 of them left. I bought two marked dallas semi from
them a few weeks ago. Counterfeit or not they worked for me
On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
Octopart says Green Tree Electronics has them:
Green Tree claims to check obsolete parts for counterfeits. I have not
bought from them but have bought from other similar distributors. Lately,
any "new" parts from eBay or Amazon or from non distributors have been
fakes, so I stopped getting parts from those sources.
Regards,
Mark
|
Re: TDS3032 Will not Finish Bootup
On Mon, Nov 19, 2018 at 6:31 PM Dewey Wyatt <kn4wddewey@...> wrote: Nac in Florida had 28 of them left. I bought two marked dallas semi from
them a few weeks ago. Counterfeit or not they worked for me
On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
Octopart says Green Tree Electronics has them: Green Tree claims to check obsolete parts for counterfeits. I have not bought from them but have bought from other similar distributors. Lately, any "new" parts from eBay or Amazon or from non distributors have been fakes, so I stopped getting parts from those sources. Regards, Mark
|
Re: TDS3032 Will not Finish Bootup
Nac in Florida had 28 of them left. I bought two marked dallas semi from them a few weeks ago. Counterfeit or not they worked for me Sent from Mail for Windows 10 From: David Kuhn Sent: Monday, November 19, 2018 8:15 PM To: [email protected]Subject: Re: [TekScopes] TDS3032 Will not Finish Bootup ¡° Arrow.com does free shipping lately...no need to pay digikey by check and wait, Arrow loses money delivering parts to you. Not many counterfeits come from them.¡° Thank you John. Unfortunately, they done have that chip. Dave On Mon, Nov 19, 2018 at 7:22 PM John Griessen <john@...> wrote: On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
There are several suppliers of the DS1742W-120 version. Arrow.com does free shipping lately...no need to pay digikey by check and
wait, Arrow loses money delivering parts to you. Not
many counterfeits come from them.
--- This email has been checked for viruses by AVG.
|
Re: TDS3032 Will not Finish Bootup
On Mon, Nov 19, 2018 at 10:42 PM, David Kuhn wrote:
Is there a button combination to cause a RESET during power-up?
There is a small hole in the rear panel. If you insert a tooth pick or any other thin rod or screwdriver and push a little to activate the switch the scope and hold it while you power up the scope it should boot up in adjustment mode and there will also be a menu item to do a factory reset. I don't know though if it will boot with blank or corrupted RAM chip but it could be worth a try. /H?kan
|
Re: TDS3032 Will not Finish Bootup
¡°
Arrow.com does free shipping lately...no need to pay digikey by check and
wait, Arrow loses money delivering parts to you. Not
many counterfeits come from them.¡°
Thank you John. Unfortunately, they done have that chip.
Dave
toggle quoted message
Show quoted text
On Mon, Nov 19, 2018 at 7:22 PM John Griessen <john@...> wrote: On 11/19/18 5:09 PM, David Kuhn wrote:
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
There are several suppliers of the DS1742W-120 version. Arrow.com does free shipping lately...no need to pay digikey by check and
wait, Arrow loses money delivering parts to you. Not
many counterfeits come from them.
|
Re: TDS3032 Will not Finish Bootup
On 11/19/18 5:09 PM, David Kuhn wrote: Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
There are several suppliers of the DS1742W-120 version. Arrow.com does free shipping lately...no need to pay digikey by check and wait, Arrow loses money delivering parts to you. Not many counterfeits come from them.
|
Re: TDS3032 Will not Finish Bootup
¡°I suppose you could google search for a website that discuss how to wire in a battery replacement in one of those Dallas modules, I know I've seen them.¡± Hello David. I¡¯ve had good luck with China in the past, until now. The -120 suppliers are all Chinese too. I did find several you tube videos on Dremal-ling in to the chip finding the battery and wiring up an external 2032 cell. I¡¯m afraid to do that to my only working chip. As it stands now, this is an inconvenience, but the scope works. If I got a chip that worked, I would gladly cut in to the old chip I did apply with eBay for a refund. I await to hear back from the supplier. If he doesn¡¯t respond, after three days, EBAY will refund my money and print me a return label. The Chinese supplier may not really be at fault, except they don¡¯t know there stock is bad or fake. For Chinese, it wasn¡¯t cheap $33. I would rather have a working chip than the money 8-(. What I need is someone with a TDS3032 scrapped mainboard that I could get the chip off of. Assuming it works, then I would have a chip to Dremal in to. Dave On Mon, Nov 19, 2018 at 6:27 PM David Holland <david.w.holland@...> wrote: If it came from China, its almost a guaranteed fake, and you should
try to get your money back ASAP.
AFAIK, the -120 should work, if you can find a good one. Octopart
lists a few suppliers, but none I've any experience with.
Perhaps someone on the list can recommend a sub, unfortunately, I can't.
I suppose you could google search for a website that discuss how to
wire in a battery replacement in one of those Dallas modules, I know
I've seen them.
David
On Mon, Nov 19, 2018 at 6:10 PM David Kuhn <Daveyk021@...> wrote:
Follow-up: un-soldered new chip and soldered old chip back to main board.
The scope boots again.
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
There are several suppliers of the DS1742W-120 version.
As far as I can tell, the -120 is the same thing but capable of running
faster?
Thoughts? Help please?
Dave
On Mon, Nov 19, 2018 at 4:43 PM David Kuhn <Daveyk021@...> wrote:
I had a TDS3032 that would not remember its GPIB buss Address not the
time
and date,
After some advice, I did order a Dallas DS1742W-150. It took about 6
weeks
to get.
So this afternoon, I carefully tore the scope down and replaced the
chip,
observing correct direction. While I had the scope tore apart, I
replace
the back-light tubes. An instrument I work on uses the same LCD.
After re-assembly, it will not boot past the "Digital Phoshor
Oscilloscope"
splash screen. During bootup, you do hear the hear the relays click,
the
splash screen flickers a bit and the floppy drive seeks. The splash
screen
never goes away.
As expected, I can not see it on the GPIB bus either.
Is there a button combination to cause a RESET during power-up?
I have made up firmware floppies and tries to update the firmware but
it
never asks to do that with DISK 1 of 4 installed in the drive.
I am in a bit of a panic now. I do have another working TDS3032, but
no
backup now. I just bought a used one for $1500 back in September with
a s
month Warranty. I hope I don't have to buy another one again. 8-(
I might tear it all apart again and put the old chip back on the board.
Dave
Dave
|
Re: TDS3032 Will not Finish Bootup
If it came from China, its almost a guaranteed fake, and you should
try to get your money back ASAP.
AFAIK, the -120 should work, if you can find a good one. Octopart
lists a few suppliers, but none I've any experience with.
Perhaps someone on the list can recommend a sub, unfortunately, I can't.
I suppose you could google search for a website that discuss how to
wire in a battery replacement in one of those Dallas modules, I know
I've seen them.
David
toggle quoted message
Show quoted text
On Mon, Nov 19, 2018 at 6:10 PM David Kuhn <Daveyk021@...> wrote:
Follow-up: un-soldered new chip and soldered old chip back to main board.
The scope boots again.
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
There are several suppliers of the DS1742W-120 version.
As far as I can tell, the -120 is the same thing but capable of running
faster?
Thoughts? Help please?
Dave
On Mon, Nov 19, 2018 at 4:43 PM David Kuhn <Daveyk021@...> wrote:
I had a TDS3032 that would not remember its GPIB buss Address not the time
and date,
After some advice, I did order a Dallas DS1742W-150. It took about 6 weeks
to get.
So this afternoon, I carefully tore the scope down and replaced the chip,
observing correct direction. While I had the scope tore apart, I replace
the back-light tubes. An instrument I work on uses the same LCD.
After re-assembly, it will not boot past the "Digital Phoshor Oscilloscope"
splash screen. During bootup, you do hear the hear the relays click, the
splash screen flickers a bit and the floppy drive seeks. The splash screen
never goes away.
As expected, I can not see it on the GPIB bus either.
Is there a button combination to cause a RESET during power-up?
I have made up firmware floppies and tries to update the firmware but it
never asks to do that with DISK 1 of 4 installed in the drive.
I am in a bit of a panic now. I do have another working TDS3032, but no
backup now. I just bought a used one for $1500 back in September with a s
month Warranty. I hope I don't have to buy another one again. 8-(
I might tear it all apart again and put the old chip back on the board.
Dave
Dave
|
Re: TDS3032 Will not Finish Bootup
Follow-up: un-soldered new chip and soldered old chip back to main board.
The scope boots again.
Is the new Chinese DS1742W-150 bad? There is only one supplier on EBAY,
There are several suppliers of the DS1742W-120 version.
As far as I can tell, the -120 is the same thing but capable of running
faster?
Thoughts? Help please?
Dave
toggle quoted message
Show quoted text
On Mon, Nov 19, 2018 at 4:43 PM David Kuhn <Daveyk021@...> wrote: I had a TDS3032 that would not remember its GPIB buss Address not the time
and date,
After some advice, I did order a Dallas DS1742W-150. It took about 6 weeks
to get.
So this afternoon, I carefully tore the scope down and replaced the chip,
observing correct direction. While I had the scope tore apart, I replace
the back-light tubes. An instrument I work on uses the same LCD.
After re-assembly, it will not boot past the "Digital Phoshor Oscilloscope"
splash screen. During bootup, you do hear the hear the relays click, the
splash screen flickers a bit and the floppy drive seeks. The splash screen
never goes away.
As expected, I can not see it on the GPIB bus either.
Is there a button combination to cause a RESET during power-up?
I have made up firmware floppies and tries to update the firmware but it
never asks to do that with DISK 1 of 4 installed in the drive.
I am in a bit of a panic now. I do have another working TDS3032, but no
backup now. I just bought a used one for $1500 back in September with a s
month Warranty. I hope I don't have to buy another one again. 8-(
I might tear it all apart again and put the old chip back on the board.
Dave
Dave
|
Re: 7854 RAM card upgrade only - any interest?
Curious.. more than a year further.. did the new board ever see daylight?
Leonard (7854 owner from NL)
|
Re: Tektronix 475A intermittent / lazy sweep
OK, I am looking at all this and I got something, if you can do it, and I am not sure IT will do it. In XY mode, if you can put damnear anything in, say a sine to deflect, hitting trigger view should result in a display. Whether it be a line of whatever, if you get something that clears everything up to U520. Actually U520 is a suspect here, but let's not condemn too quickly.
Now after U520 is that tunnel diode, shunting the "`A' GATE" signal. The 475 print doesn't but the poorly scanned 475A print shows a voltage of zero at that point. Also (page 6 of 14) it gives a waveform. If that is not there U520 is an even bigger suspect.
The A GATE goes to Q572, which is in a diff pair with Q574 which means that passing the signal is dependent upon Q574 being biased on so the emitters can couple. The collector of Q572 is the place to check, if a signal is not there you need the DC voltage. U600 can affect the bias on Q574, so that needs to be checked if Q572 collector does not have a pulse.
The circuit of U600 is a bit murky, it has input and output but then that diff pair. Hard to tell exactly how it works. It does seem like the outputs to those transistors are open collector or similar, but it has both Vdd and Vss so there is no way to know if it is supposed to pull up or down.
RIGHT NOW, I have a 475 on the bench, and it will stay fairly handy some for waveforms or voltages if you need. You should be able to disconnect U600 from the B of Q574 if the bias is not right. If that lets the signal pass it does not automatically mean U600 is bad. Can't condemn those things out of hand, but if it IS bad, I am planning on - even if I have to borrow the money, to go to HGR and buy up me some tekscopes. They are local and if they like cash I might just have more parts than I know what to do with. Bear with me though, I was injured and unable to work for a long time and I am just getting past that, and I might just devote myself to my own business, scopes and audio. If that works out I will be a pretty valuable resource. I would like to do that. I want to go down there and but EVERY Tek scope they have. I am sure some are junk, but just ONE unobtainium IC would make it worth it.
Moving right along, the signal goes to the base of Q902.
That 475A schematic is not that good, but good enough. You can see what happens after Q902. See where the signal stops when you think it shouldn't.
From there the circuit gets complicated. At that point we need to know where the trigger or gate signal is and is not. Pursuing all the possibilities would be counterproductive. Get to that point, and if the signal is not there go backwards.
Also remember this problem is obviously thermal. Got some Freon or even 91% alcohol ? Or solvent that is same on this thing ? you get it narrowed down and use a Qtip to apply an "evaporant" to cool the part. Shooting the stuff on 100 components tells you nothing. The trick is to catch it when it first acts up. Of course the problem has to be localized, so definitely try that once it is narrowed down.
Keep us posted. Once we now a few things we can proceed, unless you get it fixed just by that. Any component can fail from heat, and not overheat just heat. None of this is high power so you are not looking for much heat, like you might use an infrared thermometer to find. It would not work.
So basically, where does the trigger (or gate) signal stop ?
Also, I assume by what you wrote that "auto" trigger does not result in a trace. This I believe is an important piece of information but to get into it will take a bit of time. I haven't yet found out exactly where the "auto" is accomplished, but I will. Sometime tomorrow probably I will get into that and come back with more. Maybe tonight. Who knows ? I might find a dead giveaway there. (once I find the damn thing)
Fret not, I almost NEVER fail. Once I sink my teeth into something I tend to stick with it unless it is about to pull my jaw off my body. Just the way I am.
Keep us posted.
|
Re: Tektronix 2430A Questions
" There is a home version of LabView (2014 version) license available for
$49 "
Thank you!
Dave
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On Mon, Nov 19, 2018 at 1:18 PM Keith Refior <krefior@...> wrote: There is a home version of LabView (2014 version) license available for
$49.
Can be purchased through Digilent.
Here's the Digilent URL:
On Fri, Nov 16, 2018 at 11:25 PM David Kuhn <Daveyk021@...> wrote:
¡°
Thanks I am interested in that. Do you know about how much Labview would
cost to get started?¡± I just looked in to Labview tonight. $3000! Wow, I know it¡¯s a great
tool,
and probably easier, and more versatile, to program in than VBA, or VB6,
but $3000? I¡¯ll stick with manually writing my own test software VBA ( I
actually prefer it, because databasing collected data is a natural with
Access/VBA). Screw. Shots through a utility like OpenChoice Desktop and
GPIB is quite good. You grab a screen shot and paste it in to your
Calibration document in Word. OpenChoice. I do love my TDS3032s for that.
They are getting old too.
Dave
--
Keith Refior
keith@...
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zenith5106
Jeff Urban