Your instructive Videos and Your explanations encouraged me to continue the repair of my TD744A. Also Your advice to use the forum at eevblog and Tektronix was very helpful. After many changes and data-switching from one to the other NV-Rams with my MiniPro was successful and allowed booting reproduceable. A deep examination of the aquisition board with my microscope showed several broken solderpoints on the ADC for CH 2. Resoldering was difficult but successful. Now the scope works and I am happy. Not at least the contributions from FeedbackLoop were a great help and incentive for me. Many thanks and go on creating those wonderful videos.
I like to watch your repair-videos and I enjoy the way you explain it. I am new in this group and I will start with a problem concerning my TDS744A-scope. Since about half a year my Tektronix TDS744A does not start. When pressing the ON/Start-Button, several Segments on the 7-Segment display inside the scope on the Controller-board light up until the changing of the segments stops and the scope is frozen. This procedure has to be started several times and after 3 or 4 Trials, the scope boots up. The calibration and date is lost and I have to run a calibration routine (SPC) and set the date. After this procedure the scope works fine. When I switch the scope OFF, I can start it within a certain time (1 or 2 hours) without problems. Calibration and date are correct. Starting after a longer period of time, the procedure is as described before. I have desoldered the NVRAM (DS1650) and WD-Timekeeper (DS1486) and I have added sockets on the corresponding places for comfortable changing the IC`s. I have bought several 1650 and 1486 by ebay for replacement, but I was not successful. I tested the storability of the data of several IC`s with a MiniProTL866A and I found them keeping the data over several days. In different blogs I found that there has to be loaded special data on the NVRAM as on the WD-Timer. But I didn`t find any programs to be loaded. Is there anyone who had experience in this problem and can give help. I would be happy, when my scope would work again and hope for good advices. Regards Guenter
You really need a gpib to dig into these scopes. Tek didn't use the partitions with the DS1650Y so you could use the 1250 part, I do recall someone having issues with a 1250 programmer at the Tektronix user forum but I think others had success. With a gpip, reading the full error message (which is otherwise clipped on screen), erasing it, adding FFT or 1M (if your acquisition board has the memory) is trivial. The next generation of your scope with the fast acquisition system vastly improved that line of scope, more reliable too. With capacitor repairs you never know how long it will remain fixed due to the nature of the board contamination.
Hi.. are you concerned about other factory calibration data in the nvram getting overwritten with values from the other scope? Diffing the two images might point to a single byte field or value where these options are encoded, which would let you add the option without overwriting factory calibration too
From the datasheet you should be able to make a backup from the DS1650Y by using it as DS1250Y in the programmer. However programming the DS1650 could be impossible. You would first need to unprotect all the partitions in the RAM. The software for the TL866CS programmer can't really do this. You would need some manual mode to access the RAM in that specific pattern stated in the DS1650Y datasheet. I'm sure this is the reason why nothing changed when you copied the contents using the TL866CS programmer. The target RAM partitions was write protected.
Mine GQ works for 1650. The other 1486 dog broke a pin unsoldering it - it's like have a tree legged dog now. No bueno. BTW Canada says DS1486-150 could be added in the definitions if it's not in the list...
I'm about to do a swap of the dallas chips in my tds520/tds540. what is the best data copier to use and could you give me any advice on how to get the chips off the PCB without damage. I do have a solder remover gun. Also I noticed you copied the data from one scope to another to get more features? How did this effect the calibration costants? To clarify, I'm putitng in NEW chips.
I showed the GQ-4X programmer, which worked for me to copy DS1650Y. Any decent desoldering iron plus some skill should do the business. Regarding the calibration, as I said in the video, I just tried with a copy of the chip from another scope with the right set of options. Of course, the DC offsets and such were wrong right after booting up, but the signal path compensation procedure fixed that. I found nothing wrong after doing that. Good luck!
thank you comrade. I have the tds540/tds520 scopes. I believe you have the A version. The non-'A' versions use the 1245Y chips I think. FYI I have the full schematics for both scopes if you want them.
Very nice video I have a fully working 540c with 13 1f and 1m I also have a national semi gpib card and a cable. Is there any way to enable FFT via gpib that you know of. Really like your vids
Try this forum topic: www.eevblog.com/forum/testgear/hackingupgrading-old-scope-%28tds754d%29/ It seems that they give some recipe there, but I have not tried that way.
Wouldn't copying NVRAM from one device to another also copy factory calibration data which is commonly stored there and cannot be restored without using special tool chain?
+kvitekp People say that in these scopes the calibration parameters are stored in some eeprom on the acquisition board. These NVRAM chips store some settings, options, error log, probe compensation ans signal path compensation parameters.
Hi! amazing videos, amazing work! thanks. I'm currently in a battle with a 540A. Self-test shows a Fail++ processor and log shows a cpuDiagDsyAccess error. I suppose this error is related with video controller (dsy=display?). Strange because scope seems to be ok, no problems in image. Any tips? 1. totally recapped (not by me) 2. checked voltages in all caps 3. checked voltages in ICs 4. signal path compensation ok 5. checked continuity of some address lines in direction to video chip. Last note: Once (just once) the scope has passed in self-test with no errors!
Hi, i have a TDS 460 (non A), and i want to enable options (1M, vga output), but i dont know what need to do. I have a PCI-GPIB NI card, but i dont have any program and really dont know how its work. It is possible to switch on option moduls? Inside the scope there is a DIP switch but dont know what is the function of it. Can you help me enable the option moduls?
clearing the errorlog is quit simple with the TDSerrorlog tool from Hakan. it connects thruth GPIB and you can debug the errorlog and clear it.www.hakanh.com/dl/TDSErrLog.htm [you need a W98SE+NI GPIB PCII/IIA card.]
Your instructive Videos and Your explanations encouraged me to continue the repair of my TD744A.
Also Your advice to use the forum at eevblog and Tektronix was very helpful.
After many changes and data-switching from one to the other NV-Rams with my MiniPro was successful and allowed booting reproduceable.
A deep examination of the aquisition board with my microscope showed several broken solderpoints on the ADC for CH 2.
Resoldering was difficult but successful.
Now the scope works and I am happy. Not at least the contributions from FeedbackLoop were a great help and incentive for me.
Many thanks and go on creating those wonderful videos.
Great! And thanks!
Very cool. Glad you caught the discrepancy before it bit you. 😁
Yep another AWSOME video! I'll have to check out those options at work as well. Thanks again for another super post. Best Wishes n Blessings Keith
I like the way you keep the backup files handy!
I like to watch your repair-videos and I enjoy the way you explain it.
I am new in this group and I will start with a problem concerning my TDS744A-scope.
Since about half a year my Tektronix TDS744A does not start. When pressing
the ON/Start-Button, several Segments on the 7-Segment display inside the
scope on the Controller-board light up until the changing of the segments
stops and the scope is frozen. This procedure has to be started several
times and after 3 or 4 Trials, the scope boots up.
The calibration and date is lost and I have to run a calibration routine
(SPC) and set the date.
After this procedure the scope works fine.
When I switch the scope OFF, I can start it within a certain time (1 or 2
hours) without problems. Calibration and date are correct. Starting after a
longer period of time, the procedure is as described before.
I have desoldered the NVRAM (DS1650) and WD-Timekeeper (DS1486) and I have
added sockets on the corresponding places for comfortable changing the IC`s.
I have bought several 1650 and 1486 by ebay for replacement, but I was not
successful.
I tested the storability of the data of several IC`s with a MiniProTL866A
and I found them keeping the data over several days.
In different blogs I found that there has to be loaded special data on the
NVRAM as on the WD-Timer. But I didn`t find any programs to be loaded.
Is there anyone who had experience in this problem and can give help.
I would be happy, when my scope would work again and hope for good advices.
Regards
Guenter
You really need a gpib to dig into these scopes. Tek didn't use the partitions with the DS1650Y so you could use the 1250 part, I do recall someone having issues with a 1250 programmer at the Tektronix user forum but I think others had success. With a gpip, reading the full error message (which is otherwise clipped on screen), erasing it, adding FFT or 1M (if your acquisition board has the memory) is trivial.
The next generation of your scope with the fast acquisition system vastly improved that line of scope, more reliable too. With capacitor repairs you never know how long it will remain fixed due to the nature of the board contamination.
Great job and another awesome vid.. Thanks
Hi.. are you concerned about other factory calibration data in the nvram getting overwritten with values from the other scope? Diffing the two images might point to a single byte field or value where these options are encoded, which would let you add the option without overwriting factory calibration too
Good job vladimir. Excellent
From the datasheet you should be able to make a backup from the DS1650Y by using it as DS1250Y in the programmer. However programming the DS1650 could be impossible. You would first need to unprotect all the partitions in the RAM. The software for the TL866CS programmer can't really do this. You would need some manual mode to access the RAM in that specific pattern stated in the DS1650Y datasheet. I'm sure this is the reason why nothing changed when you copied the contents using the TL866CS programmer. The target RAM partitions was write protected.
Mine GQ works for 1650. The other 1486 dog broke a pin unsoldering it - it's like have a tree legged dog now. No bueno. BTW Canada says DS1486-150 could be added in the definitions if it's not in the list...
Could you copy the link to the schematics for this scope?
Thanks and Like your videos. Very thoughtful and clearly described.
+Sandra Ledger
The link to the schematics is in the description of the repair video.
The NVRAM will not only contain error log and options settings .. but also all the calibration constants ...
is this way can applied to 520a? to enable fft?
I'm about to do a swap of the dallas chips in my tds520/tds540.
what is the best data copier to use and could you give me any advice on how to get the chips off the PCB without damage. I do have a solder remover gun.
Also I noticed you copied the data from one scope to another to get more features?
How did this effect the calibration costants?
To clarify, I'm putitng in NEW chips.
I showed the GQ-4X programmer, which worked for me to copy DS1650Y. Any decent desoldering iron plus some skill should do the business. Regarding the calibration, as I said in the video, I just tried with a copy of the chip from another scope with the right set of options. Of course, the DC offsets and such were wrong right after booting up, but the signal path compensation procedure fixed that. I found nothing wrong after doing that. Good luck!
thank you comrade.
I have the tds540/tds520 scopes. I believe you have the A version.
The non-'A' versions use the 1245Y chips I think.
FYI I have the full schematics for both scopes if you want them.
i have a tds540 i repaired.. its running an older 1.xx firmware version..
any idea how upgrade it?
sorry, no idea
Very nice video I have a fully working 540c with 13 1f and 1m I also have a national semi gpib card and a cable. Is there any way to enable FFT via gpib that you know of. Really like your vids
Try this forum topic: www.eevblog.com/forum/testgear/hackingupgrading-old-scope-%28tds754d%29/
It seems that they give some recipe there, but I have not tried that way.
Thank you will check it out and let you knoe
Wouldn't copying NVRAM from one device to another also copy factory calibration data which is commonly stored there and cannot be restored without using special tool chain?
+kvitekp
People say that in these scopes the calibration parameters are stored in some eeprom on the acquisition board. These NVRAM chips store some settings, options, error log, probe compensation ans signal path compensation parameters.
Hi! amazing videos, amazing work! thanks.
I'm currently in a battle with a 540A.
Self-test shows a Fail++ processor and log shows a cpuDiagDsyAccess error. I suppose this error is related with video controller (dsy=display?). Strange because scope seems to be ok, no problems in image.
Any tips?
1. totally recapped (not by me)
2. checked voltages in all caps
3. checked voltages in ICs
4. signal path compensation ok
5. checked continuity of some address lines in direction to video chip.
Last note: Once (just once) the scope has passed in self-test with no errors!
Hi, i have a TDS 460 (non A), and i want to enable options (1M, vga output), but i dont know what need to do. I have a PCI-GPIB NI card, but i dont have any program and really dont know how its work. It is possible to switch on option moduls?
Inside the scope there is a DIP switch but dont know what is the function of it. Can you help me enable the option moduls?
what fw version are you using?
clearing the errorlog is quit simple with the TDSerrorlog tool from Hakan. it connects thruth GPIB and you can debug the errorlog and clear it.www.hakanh.com/dl/TDSErrLog.htm [you need a W98SE+NI GPIB PCII/IIA card.]
I can help you clean error logs
Thanks. I managed to clean the log. I finally got myself one of those clones of Agilent 82357B USB adapters from China, which are sold on eBay.
I'm getting a2doutputresistorch1 error
Any ideas tds540
I will have to send you my 540A and let you repair it and back up that dallas DRAM - LOL. How much?
Говорил бы по русски, чего коверкать английский.
Друг! Эй, друг! Не шуми. Кругом - люди!
Hi, i really need the NVRAM dump of a TDS640A Could you please help me?
@MichaelKingsfordGray grow up and get some manners