Fluke meters have been around for a long, long time. Heck, we’ve got a Fluke 73 that we bought back in 1985 that’s still a daily driver. But just because they’ve been making them forever doesn’t mean they last forever, and getting a secondhand meter back in the game can be a challenge. That’s what [TheHWCave] learned with his revival of a wonky eBay Fluke 25, an effort that holds lessons for anyone in the used Fluke market.
Initial inspection of the meter showed encouragingly few signs of abuse, somewhat remarkable for something built for the military in the early 1980s. A working display allowed a few simple diagnostics revealing that the ammeter functions seemed to work, but not the voltmeter and ohmmeter functions. [TheHWCave]’s teardown revealed a solidly constructed unit with no obvious signs of damage or blown fuses. Thankfully, a service schematic was available online, albeit one with a frustrating lack of detail, confusing test point nomenclature, and contradictory component values.
Despite these hurdles, [TheHWCave] was able to locate the culprit: a bad fusible power resistor. Finding a direct replacement wasn’t easy given the vagaries of the schematic and the age of the instrument, but he managed to track down a close substitute cheap enough to buy in bulk. He searched through 40 units to find the one closest to the listed specs, which got the meter going again. Fixing the bent pin also gave the meter back its continuity beeper, always a mixed blessing.
If you’re in the market for a meter but can’t afford the Fluke name, picking up a busted meter and fixing it up like this might be one way to go. But are they really worth the premium? Well, kinda yes.
“If you’re in the market for a meter but can’t afford the Fluke name, picking up a busted meter and fixing it up like this might be one way to go.”
But you need a working multimeter to do it ?
I have a Fluke 189 that got rained on :( now it’s completely dead. I found a third party (probably Chinese) replacement board online for around a 100 bucks but after seeing this article, I thought I’d try to repair mine. Unfortunately, the online source for schematics were not mentioned. Can anyone kindly post where I can obtain schematics?
https://elektrotanya.com/fluke_25_27_sm.pdf/download.html
Thanks! found the manuals. Now, if I can’t find special parts, maybe someone could direct me to where I can … or a reasonably priced repair center.
on cheap meters…i had a cheap meter for years and i loved it but its probes were always crap. and i heard, of course, you just buy decent probes and any cheap meter is nice. so i bought the ones on sparkfun specifically aimed at my use and they didn’t fit the meter. they obviously were supposed to but something was out of tolerance by a tiny margin and i simply couldn’t use the probes i bought. and that’s why i bought a fluke
I wish that serious electricians could have very safe insulated probes wired right to meters with no bananas. Covered screw terms? Then the rest of us in a low voltage world can have regular standard banana jacks without added on non-standard safety sleeves and have needle sharp hardened probe tips that don’t slip off and short out what was good like when those ball-end tips slide around.
My Fluke needs a sharps warning and I’ve poked myself more than once even through a tool bag. Now I put the minus lead alligator clip over the pointy plus end and it’s safe to go.
My Horror Fraught DVM (not the former freebie) leads have poked me through the backpack a number of times as well.
I’ve had limited success inventing ways to prevent its power switch from accidentally getting pushed on while in the backpack.
(Dead battery when I need to use the DVM)
Well, I guess “he could’ve used a 555” doesn’t really work here.
So, I’ll just comment “If it works, it’s a Fluke!”
Why can’t you use a 555?
Get ready to throw stones…
Got a bunch of Flukes (including an awesome 4-wire meter). Oddly, I rarely use them since everywhere i work has a cheap “disposible” meter at ready access. It’s pretty rare that I NEED a fluke instead of a cheapo meter and unless I had a reason these days, I wouldn’t invest in one. If I’m in the lab at work, yes, but for the tons of projects at home, typically troubleshooting, that level of quality is not needed.
But, my Fluke 73 is the only one of 4 Flukes that I paid list price (back in 1984).
The 8062 TRMS and another were less than $20 each, The 6.5 digit bench meter was $80-100.
Gotta watch the auctions.
No stones here, but my “go to” (only) meter was / is an original Fluke 87 – expensive and had to stand in line for I think three months – but sometimes it was the only meter (or maybe one of the few) that had the test ability to help me troubleshoot problems with factory automation systems (PLC’s) – and yes most of the time it was used for voltage & ohms – –
But as with every tool it is the correct selection of a tool that is important – and yes a pocket sized low cost meter would probably have worked fine – but I always knew the extra ability was there
Always been a little touchy when it comes to repairing test gear. Its one thing to do it in your own garage but in a big shop and if I was in charge it goes back to factory or gets trashed.
I was the guy everybody got mad at for taking the data test cable some tech just rebuilt and cutting it in half and throwing it away. You do not want to worry about whether it is the circuit or the cable when troubleshooting.
My father was an electronic enthusiast from the 1920s on. He joked that Fluke once held a slogan contest to which he entered, “If it works, it’s a Fluke”. He’s been gone decades now. Perhaps too much Groucho in him.
Can’t beat a Fluke, I have three, a 77, 73 and an 83V. They have survived 36+ years and probably 100,000+ repairs.
I will never give up my TS-505D multimeters! Anyone can fix them, unless the meter movement is gone. However, they’re built for warfare and rugged.