Tek TDS754c error - Page 1
Forum section: electronics / repair

author: jheatac
author_rank: Regular Contributor
timestamp: June 26, 2024, 12:28:54 am
content: Hello.Standard Disclaimer: Novice Hobby TinkererI have had this scope for 7 or 8 years. It came from eBay and not that I use 10% of the features, it has not given me any problem.I was playing with settings and probably poking at buttons I shouldn't have. When the scope wasn't acting right to me, I shut it off to start over. It now returns a failed self-test on every boot.slewrateTriDiag, **MTOUT expdata = 0x1 actual = 0x0Is there a setting I could have changed to cause this or is it just a coincidence?Is there an easy repair for this if it is internal? If it is very involved at all, I'll probably just keep my eyes open for a new scope.Thanks

author: jheatac
author_rank: Regular Contributor
timestamp: June 26, 2024, 02:23:32 am
content: I might add, that I believe it is a setting error in my poking around, but it could be a symptom as well.The scope will now hold a trace on the screen after the signal is removed. Autoset doesn't pick up a new signal. Trigger is at Ready, but it takes a press of the manual trigger button to clear out the trace and freeze a new one.The scope didn't act like that before.

author: 44kgk1lkf6u
author_rank: Regular Contributor
timestamp: June 26, 2024, 03:04:22 am
content: You should power it on, wait for a while, and then run signal path compensation. It will likely give some error. That means something is wrong. If you don't want to go through the effort of repairing it, you may still be able to use other channels for triggering. This forum also has a section for selling things.

author: jheatac
author_rank: Regular Contributor
timestamp: June 26, 2024, 05:50:35 pm
content: Quote from: 44kgk1lkf6u on June 26, 2024, 03:04:22 amThanks for the advice. I ran SPC.It returns 4 errors - duplicated for all 4 channels."ERROR: Characterized values out o""Ch1 trigger gain"I don't know what the truncated line is, but I assume out of range.It sounds to my simplistic mind that I changed a setting and wherever it is stored in memory is not accepting the new change or it is not getting updated.It also says:"Warning: Varigain setting beyon""CH1: 1.073>1.049"This message only appears for Ch1 and only appeared one time - the others repeat every time.

author: Rafiki
author_rank: Contributor
timestamp: June 27, 2024, 10:45:38 am
content: Maybe unrelated but did you reset all offsets (bias?) of all channels to zero (and maybe other settings in the same menu) before calibration? I may be completely wrong but Iseemto remember seeing this message once after playing with different probes (including active ones) and using big offsets and (no clue what else I played with)...Sorry don't want to confuse you with this. But there ring some bells in my head but can't remember why related information got erased out of my head :-(.

author: 44kgk1lkf6u
author_rank: Regular Contributor
timestamp: June 27, 2024, 01:16:36 pm
content: There is an erase setup and ref memory option in the utility menu.

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 27, 2024, 03:23:59 pm
content: First, you need to do a factory reset. Also check time and date is set correctly (It doesn't need to be set to right now, but must be a valid value. I've seen errors pop up when the time/date was corrupted).Shift > Display/Utility > Tek Secure Erase Memory soft button > Ok(You will see how to set the time here too)Then 'Save/Recall' Setup button > Recall Factory Setup soft button > OkThen reboot and once warmed up perform the SPC.If that passes ok, then run the extended self test in the Diag/Err menu, just under the Cal menu selection for the SPC.Do you have a way to connect the scope via GPIB to your PC?

author: jheatac
author_rank: Regular Contributor
timestamp: June 27, 2024, 04:58:27 pm
content: Thanks,I had already did the erase procedure a few times, however I don't remember seeing an option for restoring. I'll check that shortly and try again.

author: jheatac
author_rank: Regular Contributor
timestamp: June 29, 2024, 02:23:20 am
content: I do not believe I have a button to save/recall setup at least that I can find.I do not currently have any way to interface the GPIB. What would I need? a USB to GPIB adapter?

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 29, 2024, 06:07:54 am
content: The save/recall setup button is located second from left, on the second row down from top (not counting the buttons around the screen).