TDS 500 and TDS700 - Series A B C or D - What subsystem are common - Page 1
Forum section: electronics / repair

author: Tantratron
author_rank: Frequent Contributor
timestamp: December 16, 2019, 04:38:59 am
content: Hello,I've recently purchased a working TDS540C (2 GS/s) then trying now to repair a TDS540C Option 1G (I suppose 1G stands for 1GS/s) with Processor FAIL.Is there a document or roadmap which details what are the key differences between serie A versus serie B... up to serie D where the idea is to know if most internal boards are inter-changeable ?For exemple, does the PSU board can be plug and play into any serie A or serie B... Serie D ?Same question about the Acquisition board and what should be done practically (software, hardware) to move from option 1M to 2M ?More generally are these TDS500x and TDS700x wether monochrome or color are reliable, worth investing for repair and resell on second hand market ?Thank you, Albert

author: madao
author_rank: Frequent Contributor
timestamp: December 16, 2019, 09:31:06 am
content: 500 is just a 700 without colour. A TDS540C is TDS754C without colour.TDS500B is same as TDS700A, last serie with 68020 CPU.C Serie is frist serie with 68040 asCPU.TDS700B don't exist.But a importance notice by TDS500/700D Serie.Old and new acquisition Board requires specifed firmware (old -> v6.xx, new-> v7.xx)CPU Board of C Serie may using in D Serie (with correct firmware) . Opposite with new CPU on C -serie is also possible, but firmware must be old(v5.xx).But acquisition board interchangeability is more limited, it requiered correct firmware. Firmware from 68020 instruments doesn't run on 68040 board.PSUs interchangeability is much better, but old PSU fit only in non-Letter and 500A Serie.Since 500B/700A Serie is it same.1M/2M Option, only D Serie has 2M memory as standard, but it must be enabled manually. It is easy.RegardsMatt

author: Tantratron
author_rank: Frequent Contributor
timestamp: December 16, 2019, 10:45:08 am
content: Thank you Matt for the detailed info where I guess investment is better if only focusing on C series and D series who do run only with 68040 uC versus 68020 only on non-letter or A serie or B serie.I've never tested or seen a D series, it seems they mention DPO versus C series InstaVu: what is better or the pros and cons between C serie and D serie ?You wrote easy to enable manually the 2M memory option on the C series or D series, do you have a tutorial or easy step to follow in order to enable this modification ?As for the 2F option, is it easy as well to enable manually and if yes, any tutorial or straight forward instructions ?Not sure to understand your answer regarding the PSU sub-system: is it interchangeable between C serie and D serie ?Amicalement, Albert

author: madao
author_rank: Frequent Contributor
timestamp: December 16, 2019, 11:42:32 am
content: InstaVU is other (old, Marketing) name for DPO.Not big difference.2M Option. I say :many roads leads to rome.1.)Read of NVSRAM over GPIB(tekfwtool) and setting of bits in dump and write it back.2.) floppy NVSRAM dumper /write tools ( i'll searching topic and repost here)3.) desoldering of NVSRAM (DS1486) and setting of few bit (you got also link later)4.) enabled of option over GPIB with PASSWORD PITBULL & WORDCONSTANTsomeone.PSU is by 700A/C/D-serie same.(I write here with smartphonr, this is why, i 'll giving you link later)

author: madao
author_rank: Frequent Contributor
timestamp: December 16, 2019, 03:43:15 pm
content: to 2.) ->https://www.eevblog.com/forum/testgear/tektronix-tds500600700-nvram-floppy-dump-tool/(But writer doesn't works fine with TDS754C and TDS754D, only corrupt NVSRAM is result)to 4.) ->http://www.ko4bb.com/getsimple/index.php?id=enable-tds754d-optionsWhich adress for option? (see below links) 0x400 0000 is NVSRAM-Adress, it means: you should set bit in adress-range of 0x810 to 0x830 in dump. Important, value is word, not byte (16bit) It means 0x830: 00 , 0x831: 01https://www.eevblog.com/forum/testgear/hackingupgrading-old-scope-(tds754d)/msg753327/#msg753327regardsmatt

author: Tantratron
author_rank: Frequent Contributor
timestamp: December 17, 2019, 05:22:46 am
content: Quote from: madao on December 16, 2019, 03:43:15 pmMany thanks Matt for this link which is very detailed.So unless I'm wrong, it seems only D-series have all the memory hardware at full size potential (2M) except it requires to enable via software (i.e. GPIB). The C-series if 1M option can never be software enabled to 2M option, is this correct ?By the way, how about the Color screen, do these C or D series running black and white can be software color enabled by software ?I'll need to start another thread about how to use my MacBook Air connected to National Instruments GPIB-USB-HS interface which I've lately purchased. The interface is correctly self-tested and found if using the NI MAX software (Mac version) but for some reason it does respond with my actual TDS540C.Albert

author: madao
author_rank: Frequent Contributor
timestamp: December 17, 2019, 04:37:26 pm
content: Correct, by TDS500/700C is acquisition- board always 1M ready, 2M-Board is optional.Colour, in TDS500 is few IC missed->https://www.eevblog.com/forum/repair/conversion-tektronix-tds500-to-tds700-color-oscilloscope/msg2628540/#msg2628540Frist Problem: ADG281 is ubotanium, it is a Tek-designed IC. (but i can sell few ADG281 from dead TDS540A)Next Problem: NuColor-CRT is often dim, better replaced with TFT Panel (6.5 inch VGA is not really cheap)A notice, 540C can modding to 1 Ghz models (580C), but re-calibration with Tektronix Field adjustment software is neccesary. It is really a hateful jobs. Pleas check: Is 500Mhz enough for you ? I have tried with TDS754D, with sucess and 10 hour for full sequence of adjustment is needed (frequency response adjust eaten most time, one wrong adjust -> WASTED ! )regardsmatt

author: Tantratron
author_rank: Frequent Contributor
timestamp: December 17, 2019, 05:30:12 pm
content: Hello Matt,In my case, I'm very OK with Oscope offering 500MHz bandwidth if 2GS/s or higher. From what you describe, it is quite a pain to go after 1GHz so I guess best buy more recent oscilloscopes.When you wrote before TDS500/700C acquisition board always 1M option ready, do you mean it has the 1M option memory already soldered so it is just the firmware option which makes 50K limit or 1MRegarding the TDS500/700D acquisition board, do you confirm whatever S/N the board is 2M option ready so only again by firmware manipulation we choose 1M or 2M ?Not sure to understand, does the 500/700D series always have TFT panel (B&W or Color) whereas the 500/700C series always have CRT display (B&W or color) ?Maybe this should be another topic but if we take the complete roadmap of all tektronix starting from 2445 2455 2465, does the TDS500/700 was its successor then what was next successor ?In other words, what do you recommend as the most reliable digital scope and easy to repair or firmware update ?Is it worth to invest time, money in the TDS500/700 C or D series for use in laboratory, 2nd market to fight planned obsolescence or the lytic capacitor leaking story ?Thank you for frank guidance, Albert

author: madao
author_rank: Frequent Contributor
timestamp: December 17, 2019, 07:17:47 pm
content: Quote from: Tantratron on December 17, 2019, 05:30:12 pmYes, 1M memory is already soldered, only limit by software (NVSRAM hold this information, not Firmware in Flash)QuoteI have repaired four 700D-Series, all have 2M Memory on board and all is not enabled.QuoteIt came never with TFT from factory, it is using only retrofitting for bad CRT (a big problem with dim color-CRT (just a ordinary B/W CRT with color-shutter)) A example:http://www.simmconnlabs.com/1401/2606.htmlQuoteNext successor ? I can't answer easy. Old TDS500/700 is really high end Modell, probably is successor TDS5000 Series. TDS3000 is not successor of this serie, it is more basic, but it have many feartures of old serie.QuoteCapacitor problem (leaking SMD eletrolytics) exists only on old TDS Series into 1993/4 (TDS500/500A & TDS600/600A, very rare 700) It is not a nice repair jobs, but i have repaired someone with sucess. But i don't recommend. It is only for people, who like a sort of hardcore-repair. tekfwtool.c is good for Firmware update (flash programming works only at C /D Serie)

author: Tantratron
author_rank: Frequent Contributor
timestamp: December 19, 2019, 07:20:24 am
content: Quote from: madao on December 17, 2019, 07:17:47 pmAmazing info Matt about this TFT replacement... have you done it yourself and how expensive ?Albert

author: Tantratron
author_rank: Frequent Contributor
timestamp: July 11, 2020, 02:01:20 pm
content: Does anybody knows why the TDS714L which seems to belong to the TDS7xx-D series does not have any DPO or InstaVu button on the front panel.What is specific to the display with TDS714L front panel and display features ?Does the TDS714L could be compatible with other D series boards (main board, acquisition board) from the D series or C series ?Albert

author: Nx-1997
author_rank: Regular Contributor
timestamp: July 11, 2020, 11:30:51 pm
content: My best guess would be that the acquisition board is missing a lot of chips, similar to the 520B scope. The sample rate is only 500MS/s. The digital board is compatible with the 700D scopes with newer revision acquisition boards as far as I can see. The 7.4e 700D firmware contains 714L model, so they both use the same firmware.Link:https://www.tek.com/datasheet/tds714l

author: Tantratron
author_rank: Frequent Contributor
timestamp: July 12, 2020, 06:14:57 am
content: Has anybody tried to swap the TDS714L front panel (top has only 6+5 = 11 push buttons) so no push button below the TOOGLE switch. In other words, the TDS714L does not seem to offer the InstaVu or DPO mode as C series and D series. What i'm wondering, say we swap the TDS714L front panel with another one having the 12 push buttons (i.e. from a TDS754D or TDS754C), does the main board or acquisition board will then react and work when choosing the DPO mode ?Another way to frame my question about interchangeability of the sub-modules: what board has in charge the Software or Hardware or ASIC to offer DPO or InstaVu feature on other C series or D series (main processor board or acquisition board) ?It seems the TDS714L has as standard 1M option on its acquisition board where they have limited to 500GS/s but how do they inhibit or prevent the DPO or InstaVu ?

author: rvalente
author_rank: Frequent Contributor
timestamp: September 04, 2020, 07:18:30 pm
content: I own a TDS520 (No ABC), the options I could try to enable would 1F and 2F?

author: Tantratron
author_rank: Frequent Contributor
timestamp: September 05, 2020, 02:51:56 am
content: Quote from: rvalente on September 04, 2020, 07:18:30 pmThe 1F is option means there is a Floppy drive installed. If your floppy drive is there and working OK then you should have automatic 1F activation at start.The 2F (advanced math) can be set through GPIB manipulation, I did it on my TDS540C using my Macintosh through the USB.

author: madao
author_rank: Frequent Contributor
timestamp: September 05, 2020, 10:29:57 am
content: Quote from: rvalente on September 04, 2020, 07:18:30 pmearly TDS520 and TDS540 use same hack, but other location & solution.https://www.eevblog.com/forum/repair/hacking-of-old-tds640-and-tds540-fft-and-rs232-option/msg2776726/#msg2776726Using tektool for read/write of NVSRAM is possible, this is now my farvoit way of option hackingBut frist TDS500 Serie doesn't supporting floppy disc, -> no 1F option avaible.

author: Pete2
author_rank: Contributor
timestamp: September 24, 2023, 05:32:58 am
content: Hello, lots of good information here. Recently got a used TDS754A which was sold for parts but turned out there was nothing wrong with it. Retrofitted an LCD and replacement NVRAMs into it and it seems to work fine. Also recapped the PSU.Does anybody know if there is a significant difference in speed (as in UI/menu speed, waveform update rate with long memory enabled etc.) between A, B and C variants of the 700 Series for example? I have noticed that my 754A waveform update rate gets REALLY slow when enabling the maximum sample memory (1M). The C and D have a newer processor but is it really worth it to source a C or D variant to gain a little bit of speed...

author: Tantratron
author_rank: Frequent Contributor
timestamp: October 26, 2023, 06:52:42 am
content: Quote from: Pete2 on September 24, 2023, 05:32:58 amIt is not so easy to answer your question because first we do not have any schematics of any C/D serie, only the TDS520B schematics has been available.Since I've started this thread back in december 2019, I've purchased, repaired, reconditioned, hacked, upgraded, resold total of 9 tektronix TDS (510A 784C 540C 794D 520D 714L 784D and 754D). One of the most difficult repair was a fail BootROM which is synthetized in this threadhttps://www.eevblog.com/forum/repair/major-boot-failure-tds784d/msg5133990/#msg5133990.What I can tell you, some TDS A/B have a modern acquisition board (one PCB only) which seems to be roughly the same as the C/D versions so the question is how to interface with 68020 or 68040 processor boards with acquisition board HW and SW. Older A/B acquisition boards have 3 separate PCB's so I do recommend them, loose of time and very old firmware.The repair of the TDS784D has taught me one key thing, namely the DRAM sits with the Kernel with A/B serie but outside C/D serie. Tektronix kept the same Kernel circuit then same control with Acquistion board in C/D but there is a special U1 chip which translates 68040 world to 68020 world. There is 68040 bus, processor, the graphics and display are the same as 68020 except there is no ASIC translator.Attached again my hand sketched partial reverse engineering of C/D logic board then look the U1 chip and the DRAM which are outside kernel compared to A/B structure attached as well.Intuitevely I'd tend to think 68040 are faster than 68020 even though their acquisition board are really the same HW/SW architecture for latest A/B's if and only if latest acquisition board single PCB. The advantage of 68040 firmware could be an optimized code from tekronix, for sure their firmware version is changed but the real question of speed when using 1M or 2M mode, not sure because these boards really are the same.So either U1 chip introduces delay or slow down or tektronix really optimized the complete flow down thanks to 68040.Note that I've never seen TDS754A acquition board, maybe you could open the blue cabinet and share a global view picture to see if it is monolithic PCB or old 3 parts.Albert

author: Pete2
author_rank: Contributor
timestamp: October 30, 2023, 09:37:49 am
content: Quote from: Tantratron on October 26, 2023, 06:52:42 amThanks for your info. Much appreciated.Well the ACQ board is a single large PCB. I don't have a picture at the moment but I'll try to remember to take some the next time it's out of the instrument shelf.