Fluke 87 Corrosion - PCB Hack - Page 1
Forum section: electronics / testgear

author: dapug
author_rank: Newbie
timestamp: April 07, 2018, 10:24:50 pm
content: I bet your Fluke 87 PCB doesn't look like this near the battery connector:Here is the back side, you can see this is nothing more than a jumper to connect the positive battery lead to the positive line for main power to the meter.Reason for the jumper? Battery corroded. The pics show the PCB after I cleaned it up a bit, but here is the case before I cleaned it:But... WHY? Why is this jumper necessary? How did the trace (which must be inside, between layers of fiber board) get corroded? There was absolutely no continuity between these two pads on the PCB. I first tried solder removal/re-flow with fresh solder, to no avail. I then had no choice but to run this stupid bus wire to get me back up and running again.BTW: lesson learned, always use top brand batteries! (Energizer, Duracell, whatevs). I've left batteries in this thing for many years without issue, but the ONE time I go with a cheapy brand, I get this corrosion crap in less than a year. grrrr.

author: Electro Detective
author_rank: Super Contributor
timestamp: April 07, 2018, 11:24:53 pm
content: Quote from: dapug on April 07, 2018, 10:24:50 pmYou won't do much better today with top brand batteries either, they are the ones I've had to pry their spilled guts out of a few Flukes in the last few years,and saw less cheapies which die quicker so replacement is inevitable before they leakIt's luck, not price or brand rep anymore, perhaps rechargeables might fare better, but I've seen those corrode and jizz tooYou got away with it cheap on your 87, had it been AAA or AA powered Fluke 189, 289, 381 models etc... ouchFWIW, I dab some WD40 on the battery and connector contacts with a Q tip/cotton bud, and it seems to keep any metal to metal reactions at bay,i.e. no green muck or crustiness develops, and I make sure no loose or shaky battery connection either.It pays to check all your battery devices once a year and all at oncethe lazy days of getting 10 years out of a battery in a 'casual use' meter are over

author: Electro Detective
author_rank: Super Contributor
timestamp: April 08, 2018, 10:38:40 pm
content: I forgot to suggest to remove that foam bit in the battery compartment, which eventually turns to sticky goo and makes a mess,and doesn't keep the battery from rattling about either. Yours is probably bathed in battery leak gunk tooI've seen the 'melted' foam stuff in hot conditions turn to liquid runny goo and over time crawl into the electronics... and thought it was battery acidManufacturers of cheap and overpriced battery powered equipment (and car engine bays) still aren't getting it after decades of foam perish causing issuesPlus I suspect the foam emits vapors whilst it deteriorates over time and won't do your sealed meter internals any favorsWhy they don't put a better quality foam or springy thingie in there on pricey meters is...I usually put a piece of good quality white springy packing foam (from large TV packaging, good useful stuff which people toss out)or in a pinch some thick springy cardboard or make a wad of rolled up electrical tape in the same shape as the battery,or electrical tape around the cardboard,any of the above works good enough, or better... and one thing less to think about

author: BradC
author_rank: Super Contributor
timestamp: April 09, 2018, 01:17:50 am
content: Quote from: Electro Detective on April 07, 2018, 11:24:53 pmI'm trying out a couple of these :http://www.altronics.com.au/p/s4908B-9v-nexcell-lithium-battery/Expensive, but they have about the stated capacity at a multi-meter sort of load and don't nosedive in the heat like Alkalines. The Energizer Ultimate-Lithium is cheaper and probably much the same.

author: dapug
author_rank: Newbie
timestamp: April 09, 2018, 04:00:29 pm
content: Good point on the foam issue.Interesting strategy with lithium alternative.I suppose battery corrosion is to be expected, but the two things I found most unexpected here were:It wasn't an issue for me for 15 years (that's how long I've had this Fluke 87) until just this year, and,How did it eat the trace internally?? (Outer leads, sure, but the trace inside the board... what the?)Learned something new anyway