Tek TDS420 help?
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From: Nico Coesel on 1 Feb 2010 11:57 DaveC <invalid(a)invalid.net> wrote: >This scope has the famous "FAIL ++ Acq" error which points to the infamous >failed (and leaking) SMD caps on the acquisition PCB. > >I'm moving on to troubleshoot another (unrelated, I think -- and hope) issue. Tektronix has an excellent user forum covering these sort of repairs. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico(a)nctdevpuntnl (punt=.) --------------------------------------------------------------
From: DaveC on 1 Feb 2010 11:59 > On Sun, 31 Jan 2010 12:49:09 -0800 DaveC <invalid(a)invalid.net> wrote in > Message id: <0001HW.C78B2CC50195EC48B0B2D9AF(a)news.eternal-september.org>: > >>> All my experience is with the 540, but I think you're wasting your time >>> trying to troubleshoot ANYTHING >> >> OK, I suspected that, but non-functional buttons seemed a symptom not >> related >> to caps issue. But I'll take your advice to heart and do *all* the caps. >> >>> until you replace ALL, AND I DO MEAN >>> EVERY SINGLE ONE on every board, the caps and CLEAN >>> CLEAN CLEAN and CLEAN again the circuit boards. >> >> Yeah, I plan to do that. Making a complete list right now. >> >> What techniques and chemicals did you use? > > I use Simple Green with a good non-metallic brush, then follow up with 90% > isopropyl alcohol. For the rubber membrane contacts VERY gently clean with > alcohol and pat dry. Thanks JW for your reply. Serious cleaning ahead! Dave
From: DaveC on 1 Feb 2010 12:02 > The method I use for cleaning those conductive pads on button switches > (keyboards, IR remote controls, etc) is very lightly scuffing them with a > pen-type tool that has strands of glass fibers in it. > [...] > WB Thanks for that input Bill. I'll see if scrubbing lightly helps. The flex pcb switch contacts are more what I suspect than the button. And those are seriously fragile. It looks like a tiny bead of carbon-filled rubber cement. I dented a trace (actually chipped off a *tiny* piece) with a DMM test probe. Yikes! Thanks again, Dave
From: DaveC on 1 Feb 2010 12:03 > Tektronix has an excellent user forum covering these sort of repairs. Thanks Nico. I'll check it out. Dave
From: DaveC on 1 Feb 2010 13:11
> Tektronix has an excellent user forum covering these sort of repairs. Nothing I could find regarding the button switches. Can you point me to a Tek forum topic about button contact repairs? Thanks, Dave |