Dead Tek TDS580D repair chances? - Page 1
Forum section: electronics / repair

author: dzseki
author_rank: Frequent Contributor
timestamp: September 06, 2020, 12:15:12 pm
content: There is a dead Tek TDS580D on a local site for 450EUR. I know that the price is on the high side for a dead scope, but here in hungary these are not that common, so buying anything off ebay (+ shipping + import taxes) wouldn't make those much better deal either.Anyway seller says it was working a month ago, and now only "clicks" one with powering up but nothing else happens.Assuming the seller is honest what are the chances with the repair? Also, what can you tell me about this scope generally? I can look up the specs sheets of course, I'm more interested in the general reliability (compared to its age) weak points, or how hackable is (is there any good options to be enabled for ever) etc.

author: madao
author_rank: Frequent Contributor
timestamp: September 06, 2020, 01:05:09 pm
content: If you can turn it on and it make nothing live sign except front LED, correct?450€ is high risk. Can you visit seller and pull him out of cabinet and look, what does show the 7 seg-Display?possible fail: Firmware corrupt(i didn't thought) or dead cpu board (very possible). It is with patient fixable. Important tool: tektool (and GPIB-card) and service console port -adapter. I have fixing serveral this family, also with CPU board fail.No problem with bad SMD eletrolytics. (only early modell has this notorius failure)Relaibity: yes , only one weak point: NVSRAM by monochrome modell. (Color CRT on colour-Modell aka TDS700 series is short living)Hacking: easy.greetingsmatt

author: andy2000
author_rank: Frequent Contributor
timestamp: September 06, 2020, 02:35:31 pm
content: My first thought would be either a power supply problem, or something loading down the power supply. I've seen leaking caps in the power supply, and monitor cause this in the older models, but not in the D series. I'd take a dead scope over one with cryptic errors since it's more likely to be something basic like the power supply. On the other hand, there's no telling what other problems you might find after you get it to power up.

author: madao
author_rank: Frequent Contributor
timestamp: September 06, 2020, 03:34:25 pm
content: Dead PSU is possible, but it is rarely by newer TDS500 series. But check of their capacitor is good way, i saw one with leaking THT eletrolytics.This is why, i ask him: Power up and only front LED light up, correct? I would be glad, if theard starter write a answer, then can i tell more, how to.Greetingsmatt

author: dzseki
author_rank: Frequent Contributor
timestamp: September 07, 2020, 09:30:33 am
content: Thanks for the input gentlemen.Unfortunately I do not know more than what I wrote in the starter. I've just contacted the seller, will see if he gets back to me. The scope is located a hour of drive from me, so if I make a visit I should be prepared for anything.

author: madao
author_rank: Frequent Contributor
timestamp: September 07, 2020, 04:02:59 pm
content: Good, here little check list.If unit is going power on and all LED on frontplate light up.No -> talk about price and buy it. Of coruse a bit risk.. ( i have running PSU from TDS540A )Yes -> next step: Pull TDS580D out of cabinet and look on 7 Seg-display. Here must some live. If display show some life and (8. is bad !)Then look on nvsram protection switch. If it show excatly as pictures -> buy it instant and take it at home, then you can switch it to protected and unit runs again. I got one TDS640 with "no life", it was only protection switch.By other case: if switch is on protected and unit show no life except 7-seg display, you can make think about it and talk with other price.Greetingsmatt

author: dzseki
author_rank: Frequent Contributor
timestamp: September 07, 2020, 09:52:18 pm
content: Thanks Matt!The seller says that the LEDs are dead, and the fan does not start either, it is only the "standby relay" that is switching by pushing the power button. I guess then this can be either in the power supply itself, or a short somewhere...He says that it has got +memory option (didn't tell which) and the FFT is not enabled. I asked about the SPC and I was told that when the scope functioned the SPC ran well on all channels, the scope was officially calibrated in 2013.The price is negotiable and upon personal inspection we can even remove the lid.