Great work so far, Tony. I hope you can get the firmware re-loaded. Many of the Dallas chips are still available - new ones are sold under the "Analog Devices Inc./Maxim Integrated" brand name with similar part numbers and compatible pin-outs (I believe Maxim Semiconductor bought Dallas and then Analog Devices bought Maxim). I solved the dead RTC problem in my Tektronics TLA-704 logic analyzer using a Maxim DS12885 to replace the Dallas DS1285. The Maxim chip allowed me to easily add an external battery too. Regards, David
Well Tony. You are braver than me. I would be more than happy to have replaced the IC's but on camera would be a big no for me. In fact you done that job so neatly I am wondering if you had Paul Carlson doing the soldering work for you off camera. (lol) One of the really nice things about using the IC sockets is that it removes any concerns about soldering iron heat transfer into the device. That said I do dislike pushing any IC into a socket for fear that one of a pin will bend over. That was a really interesting video and nice to see you making use of those soldering skills. I am sure you will get there in the end. Ian
You can speed up the boot process a bit by switching all the switches on the red DIP switch on the processor board to the 'open' position (switched towards the numbers). Tek did this on the later units to skip some of the extended boot tests. I also have NVSRAM images for firmware version 1.1e and 4.0e if you need them.
The life of these BB chips is extended by leaving the instrument on. As long as it is running the batteries don't have to provide power. But you still have the chemical degradation that occurs with time.
Tony thank you for the time you spend working with this unit. the place you got the new chips, they can send you the chips already programmed with the firmware, are the new chips pre-programmed with the oscilloscope firmware?
What firmware version was on the scope originally when working before the NVRAM battery when flat? I might have the backup file for it as have for most of the versions. I do remember below a certain firmware cause a error at startup and won’t boot if flash boot rom don’t match NVRAM? I do remember the early A versions do store cal constants on NVRAM area as well, some didn’t? The later B and all C D it on the acquisition board on two EEPROM. I can get the old board working again but would need the acquisition board to do a full calibration as requires a data precision 8200 voltage source and level signal generator above 1 GHz and pulse generator which I happen to have as repaired way to many of these scopes over the years. If you live in the area I just let you borrow the voltage source since you have already the gpib interface card and like other stuff needed. It better to fix it then give up they are old but good scopes when working. Honestly not a big deal if you lost the calibration data as you have to calibrate it to get 1 GHz anyways otherwise trigger will be off and you get double ghost traces at higher frequencies if you don’t calibrate. That CPU board likely fine as it booted before NVRAM corrupted data in you other video. I can also sent you the file if know the version of firmware it had when it did boot. More likely cal data be gone and defaults to initialize values. It will boot but you get fail on CPU and Cal if cal was stored on NVRAM area. I also have a super pro 610p rom programmer you can use a GQ 4x4 programmer you have to set offset when reading and writing so not in clock area as not directly supported but does work as used it as well, but if battery is gone pointless as data will be likely corrupted. First step is get the firmware going and then other issues can be resolved. It be a excuse to do the 1ghz bandwidth and other options, so calibration data being lost is not important in that case.
Thanks for the info, i think i had 1.1e , i will try again the old board and restore the firmware to 1.1e and the NVSRAM backof of that version. The new board is also not 100%, i have an prcossor error, but it still boots and starts , self calibration works but i cant read from GPIB, maybe thats the error. i have a terminal adapter too, so maybe i can do some things from there and not need to use the GPIB .. only the FAS calibartion will not work without it.
Thanks so much for all the info you have here. I have the TDS644 with the surface mount crap-electrolytic caps and low LCD screen brightness. Do you address that anywhere?
Thanks Laszlo, i just ordered a used mainboard on ebay, as i am stuck.. i think more is wrong. give me a change to compare. i still want to upgrade it. i build the pc to fun the field software in dos have an RF Amp to pump up my FR gen...as it needs high lever to calibrate. so its allmost there
@@TonyAlbus Thanks for your reply! I'm sure you will fix it at the end. I'm just waiting for my second hand 744a and if not at the first, I may try the upgrade later (of course currently I don't have the devices for it to execute). Hope the scope will arrive in working condition. If I can help you with any comparison between the devices, please let me know! Wishing the best and keep us informed with progress!
Hi, Nope, still broken, my backup was not good, the Dallas chips were allready not good. so make a backup while you still can. i downloaded an backup from someone else from the Tekwiki ... maybe that works.. still need to try.
@@TonyAlbus Wait, what do you mean, the legacy Dallas chip were not good or the ones which you bought from David in USA ? How did you upload a valid DS1486 backup, tekfwtools or programmer ?
@@tantratron Hi, i am sure the Dallas from David are good, i just had bad luck on my old chips. they were good enough to start the scope, but getting the backup was to much. i used the tektool. i recorded it all it must be someware on video.
@@TonyAlbus OK I see now your situation where myself have repaired hacked upgraded total of nine TDSxxxA/C/D. My kind advice is that you rather get a valid NVRAM content because probably your copy of old DALLAS is corrupted. Their battery started to fail, it corrupted the DS1486 content so wether you made a backup or not, only solution to repair your TDS7444 is rite a valid content. Not ethe DS1650Y or DS1250Y does not really matters, all these TDSxxx can run only with DS1486 but if DS1486 is corrupted then it will brick your oscilloscope. Too bad we are far away, I live near Toulouse
Hi, oh.. sort of forgot that project... i did get an other board and it did start, but i want this board to work, becouse the replacement board i found, the GP-IB did not work.. so need to re- start again.
I tried on ISA and PCI, i try not the use the USB as i trust more my pc boards. i was taking about the GPIB itself on the Tek mainboard that was broken on the replacemnet mainboard... one time i will fix it. so many other projects going on.
I was in the middle of repairing my 644a with acquisition errors when it froze. I cycled the power and now nothing but a black screen. I reckon the nvram has died whilst powered as it froze during use it didn't go off so to speak.
![ละลาย (LALALYE) - DAOU PITTAYA ต้าห์อู๋ พิทยา [OFFICIAL MV]](http://i.ytimg.com/vi/wo6r9TgausI/mqdefault.jpg)
Beauty and joy for ever! Hope it will work.
Thank you!
A step closer Tony. Nice work there.
Thank you Paul!
Great work so far, Tony. I hope you can get the firmware re-loaded. Many of the Dallas chips are still available - new ones are sold under the "Analog Devices Inc./Maxim Integrated" brand name with similar part numbers and compatible pin-outs (I believe Maxim Semiconductor bought Dallas and then Analog Devices bought Maxim). I solved the dead RTC problem in my Tektronics TLA-704 logic analyzer using a Maxim DS12885 to replace the Dallas DS1285. The Maxim chip allowed me to easily add an external battery too. Regards, David
Thanks David, good to know there are more options...
Well Tony. You are braver than me. I would be more than happy to have replaced the IC's but on camera would be a big no for me. In fact you done that job so neatly I am wondering if you had Paul Carlson doing the soldering work for you off camera. (lol) One of the really nice things about using the IC sockets is that it removes any concerns about soldering iron heat transfer into the device. That said I do dislike pushing any IC into a socket for fear that one of a pin will bend over. That was a really interesting video and nice to see you making use of those soldering skills. I am sure you will get there in the end. Ian
Thank you Ian.. all most there :)
Another great video. Thanks Tony.
Thank you Ralph!
You are great Tony, you managed to give me a scare on the #19:22, I can say that I love your work and I wanted to say Thank you! for sharing :)
Thank you!
You can speed up the boot process a bit by switching all the switches on the red DIP switch on the processor board to the 'open' position (switched towards the numbers). Tek did this on the later units to skip some of the extended boot tests.
I also have NVSRAM images for firmware version 1.1e and 4.0e if you need them.
Hi Jared, thank you so much, yes will try the dipswitches and for sure i DM you about those images, thank you for offering mate!
The life of these BB chips is extended by leaving the instrument on. As long as it is running the batteries don't have to provide power. But you still have the chemical degradation that occurs with time.
Yes that could be, but i will not leave it running...
Hi Tony, I have the same Oscilos Tek in my lab.... Very Good Machine...!!
Very nice! , yes are nice machines!
Tony thank you for the time you spend working with this unit. the place you got the new chips, they can send you the chips already programmed with the firmware, are the new chips pre-programmed with the oscilloscope firmware?
Thanks, yes i asked to load it with my firmware, but somehow it did not work. but great company indeed.
What firmware version was on the scope originally when working before the NVRAM battery when flat? I might have the backup file for it as have for most of the versions. I do remember below a certain firmware cause a error at startup and won’t boot if flash boot rom don’t match NVRAM? I do remember the early A versions do store cal constants on NVRAM area as well, some didn’t? The later B and all C D it on the acquisition board on two EEPROM. I can get the old board working again but would need the acquisition board to do a full calibration as requires a data precision 8200 voltage source and level signal generator above 1 GHz and pulse generator which I happen to have as repaired way to many of these scopes over the years. If you live in the area I just let you borrow the voltage source since you have already the gpib interface card and like other stuff needed. It better to fix it then give up they are old but good scopes when working.
Honestly not a big deal if you lost the calibration data as you have to calibrate it to get 1 GHz anyways otherwise trigger will be off and you get double ghost traces at higher frequencies if you don’t calibrate.
That CPU board likely fine as it booted before NVRAM corrupted data in you other video. I can also sent you the file if know the version of firmware it had when it did boot. More likely cal data be gone and defaults to initialize values. It will boot but you get fail on CPU and Cal if cal was stored on NVRAM area.
I also have a super pro 610p rom programmer you can use a GQ 4x4 programmer you have to set offset when reading and writing so not in clock area as not directly supported but does work as used it as well, but if battery is gone pointless as data will be likely corrupted.
First step is get the firmware going and then other issues can be resolved. It be a excuse to do the 1ghz bandwidth and other options, so calibration data being lost is not important in that case.
Thanks for the info, i think i had 1.1e , i will try again the old board and restore the firmware to 1.1e and the NVSRAM backof of that version.
The new board is also not 100%, i have an prcossor error, but it still boots and starts , self calibration works but i cant read from GPIB, maybe thats the error.
i have a terminal adapter too, so maybe i can do some things from there and not need to use the GPIB .. only the FAS calibartion will not work without it.
Great work and don't use flux 👍
Thank you!
Thanks so much for all the info you have here. I have the TDS644 with the surface mount crap-electrolytic caps and low LCD screen brightness. Do you address that anywhere?
Hi Scott, i have not that problem yes, but when i do, i will video it. there are nice videos about it in youtube by others.
Hi! Nice progress and video! Were you able to finish the fix and upgrade the scope to 1GHz finally?
Thanks Laszlo, i just ordered a used mainboard on ebay, as i am stuck.. i think more is wrong. give me a change to compare. i still want to upgrade it. i build the pc to fun the field software in dos have an RF Amp to pump up my FR gen...as it needs high lever to calibrate. so its allmost there
@@TonyAlbus Thanks for your reply! I'm sure you will fix it at the end. I'm just waiting for my second hand 744a and if not at the first, I may try the upgrade later (of course currently I don't have the devices for it to execute). Hope the scope will arrive in working condition. If I can help you with any comparison between the devices, please let me know! Wishing the best and keep us informed with progress!
Thank you, yes lets keep in touch, i hope it arrives in good condition for you!
That's all I use...PIN Sockets.
Yes good quality
I'm bit lost, did you finally fix and wrote the right content on the NVRAM's chips so the TDS744A works again ?
Hi, Nope, still broken, my backup was not good, the Dallas chips were allready not good. so make a backup while you still can. i downloaded an backup from someone else from the Tekwiki ... maybe that works.. still need to try.
@@TonyAlbus Wait, what do you mean, the legacy Dallas chip were not good or the ones which you bought from David in USA ?
How did you upload a valid DS1486 backup, tekfwtools or programmer ?
@@tantratron Hi, i am sure the Dallas from David are good, i just had bad luck on my old chips. they were good enough to start the scope, but getting the backup was to much.
i used the tektool. i recorded it all it must be someware on video.
@@TonyAlbus OK I see now your situation where myself have repaired hacked upgraded total of nine TDSxxxA/C/D. My kind advice is that you rather get a valid NVRAM content because probably your copy of old DALLAS is corrupted. Their battery started to fail, it corrupted the DS1486 content so wether you made a backup or not, only solution to repair your TDS7444 is rite a valid content. Not ethe DS1650Y or DS1250Y does not really matters, all these TDSxxx can run only with DS1486 but if DS1486 is corrupted then it will brick your oscilloscope. Too bad we are far away, I live near Toulouse
Świetna robota te Dallas są problematyczne po latach :)
Thank you, yes they are..
If one day I need the FirmWare, can you provide it to me...?? Thank you Best Regards...!!
Yes no problem!
Did you ever get your TDS744A running again ?
Hi, oh.. sort of forgot that project... i did get an other board and it did start, but i want this board to work, becouse the replacement board i found, the GP-IB did not work.. so need to re- start again.
But the fake china Agilent 82357B gpib did work on the previous board ? So many people say don't use that.@@TonyAlbus
I tried on ISA and PCI, i try not the use the USB as i trust more my pc boards. i was taking about the GPIB itself on the Tek mainboard that was broken on the replacemnet mainboard... one time i will fix it. so many other projects going on.
I was in the middle of repairing my 644a with acquisition errors when it froze. I cycled the power and now nothing but a black screen.
I reckon the nvram has died whilst powered as it froze during use it didn't go off so to speak.
Hate when that happends, hope you can fix it.
🎉
Thank you!
You screwed up the firmware. The firmware isn't in the dallas chips. It's in the flash chip
nope