Neutralizing/cleaning capacitor electrolyte from Fluke hand-held 80xx boards - Page 1
Forum section: electronics / repair

author: Excavatoree
author_rank: Frequent Contributor
timestamp: January 29, 2024, 03:14:19 am
content: I've frequently passed on the advice to check the capacitors in the hand held 80xx meters (8020, 8060, 8024 et al) both "A" and "B" versions, but, embarrassingly, I've found some that I neglected to check. (Most of my meters had capacitors that weren't leaking yet, or were so far gone I didn't bother repairing them.)I got one meter in time, but there is some electrolyte on the board that has discolored the tinned traces. Forgive me if this was mentioned before and I missed it, but what should I used to clean this electrolyte and ensure that the residue won't continue to corrode the traces? I've used ethanol on cotton swabs and the dreaded fiberglas pen. (which I understand some swear by, some swear at)I don't want to replace the capacitors and still have a problem, so if anyone has any advice, I'd appreciate it.

author: Haenk
author_rank: Super Contributor
timestamp: January 29, 2024, 08:56:25 am
content: mild vinegar, preferably warm, will do a good jobrinse with a lot of destilled waterI also did just plain hot tap water on a lot of things, would not suggest that on delicate electronics though.dry very well before powering it up*however* this leaked out electrolytics are sneaky bastards - they will follow traces in buried layers, cables etc. That's the reason you might want to clean up the mess ASAP. If there is only minor leakage, more damage might not even happen at all. If a lot of leakage happened and the board got soaked this might mean "game over" eventually, as corrosion might have killed traces inside the PCB and as well might appear everywhere on the PCB.

author: TERRA Operative
author_rank: Super Contributor
timestamp: January 29, 2024, 12:55:42 pm
content: Unless the board has particularly sensitive parts, I throw them in the dishwasher when my wife isn't looking.If that kills the board, well, it was ready to die anyway......I also lift the soldermask if the electrolyte has got underneath as Haenk mentioned. It can often be carefully scraped back with a flat-head screwdriver.Here's a repair I did from a leaking backup battery in a HP 4276A LCZ meter.Before cleaningAfter cleaning.Soldermask removed to clean out the electrolyte.

author: Excavatoree
author_rank: Frequent Contributor
timestamp: February 01, 2024, 12:17:10 am
content: I'm glad I caught the leaking capacitors before it got that bad.I was trying to avoid it, but I did unscrew the ribbon cable connecting the two boards of the 8024b and I removed a diode that was in the way to get enough access to it to clean it well.One thing I didn't know, the 8024b uses a board with more layers than 2. I'm sure the others do this as well, but I haven't checked. I was going to start a new thread, but I don't think that fact justifies a new thread, and I couldn't find one of the old meter threads.

author: Excavatoree
author_rank: Frequent Contributor
timestamp: February 01, 2024, 12:19:22 am
content: Sorry, I forgot to add: User Haenk advised me to take care of it ASAP. That's my advice to other forum members as well. I'm embarrassed that I didn't take it, myself. A few just slipped by, and I never realized I need to check them as well.

author: lowimpedance
author_rank: Super Contributor
timestamp: February 01, 2024, 02:24:09 am
content: Also with this series of push button meters you may get PCB surface contamination under the range switches which can make for some 'unusual' readings, so after repair and cleaning things are not quite right a clean under those switches might be the go.....or as TERRA mentioned ..... dishwasher.I always marvel at how shinny the dishes are from my dishwasher , haven't tried a PCB though