Fluke 87 Corrosion - PCB Hack

[dapug]

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.

[Electro Detective]

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.

You 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 leak 

It's luck, not price or brand rep anymore, perhaps rechargeables might fare better, but I've seen those corrode and jizz too 

You got away with it cheap on your 87, had it been AAA or AA powered Fluke 189, 289, 381 models etc... ouch   


FWIW, 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 once
the lazy days of getting 10 years out of a battery in a 'casual use' meter are over   

[Electro Detective]

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 too 

I'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 acid    

Manufacturers of cheap and overpriced battery powered equipment (and car engine bays) still aren't getting it after decades of foam perish causing issues   

Plus I suspect the foam emits vapors whilst it deteriorates over time and won't do your sealed meter internals any favors

Why 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 

[BradC]

It pays to check all your battery devices once a year and all at once
the lazy days of getting 10 years out of a battery in a 'casual use' meter are over   

I'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.

[dapug]

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