Fluke 87 IV Repair help! - Page 1
Forum section: electronics / repair

author: Zamagen
author_rank: Newbie
timestamp: January 08, 2025, 09:19:20 pm
content: Hello,I've had this meter for a while, bought 2nd hand fully working, never had any problems.Suddenly it started beeping continuously with each position of the dial; I've read the problem could be caused by dirty sockets, soI desoldered, soaked in alcohol and resoldered the connectors.Now it doesn't beep anymore, but it seems that the inputs are non functional.I can't measure a DC voltage or a resistance, if I take another meter and measure the internal resistance between com and V/Ohm I get an open circuit, but according to other posts it should be some MOhms.I can't see broken/missing parts and the resistors seem to be Ok.Does someone have any possible hint on what could be the problem?TIA.

author: m k
author_rank: Super Contributor
timestamp: January 19, 2025, 07:11:29 am
content: Schematics for old version is available.Have you assembled it correctly?

author: silly sausage
author_rank: Regular Contributor
timestamp: January 19, 2025, 03:13:48 pm
content: regarding the input sockets, my 83v did the same,tried cleaning with no luck, in the end i unsoldered the socket block then put it inside a sock and threw it in my washing machine, then let it dry and refited it, its been fine since.

author: Zamagen
author_rank: Newbie
timestamp: January 19, 2025, 06:32:12 pm
content: I'm pretty confident the problem is in the metal contacts inside the rotary switch.But I've tried bending them back and forth so many times that one broke. Is there a source for compatible contacts?

author: coromonadalix
author_rank: Super Contributor
timestamp: January 20, 2025, 12:30:30 am
content: you find them on Ebay at astonishing prices per part .... unless you find some 87iv 89iv 187 189 for parts and they are there ??

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 20, 2025, 06:26:32 am
content: If I remember right the Fluke 87 IV is more or less identical to the 187/189. In that case I was helped by couple of (non-Fluke) documents that written up in Chinese for diagnosing and repairing some problems with 187/189 multimeters in this thread:-https://www.eevblog.com/forum/repair/fluke-187189-repair/msg3205856/#msg3205856That particular post has the documents that have been auto-translated from Chinese to English. The auto translation is dicey and can be hard to follow, but you might be able to get some ideas for areas to look at.the problem with my 187 was that when measuring something with a high resistance, the high ohms range would take a long while (like minutes) to settle on a reading. When the probes were left off it would seek instead of displaying "0L". The fix as suggested in those documentswas to soak the PCB in 99% isopropyl alcohol- I was amazed that the procedure worked.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 20, 2025, 06:41:47 am
content: Quote from: coromonadalix on January 20, 2025, 12:30:30 am$20 shipped within the US. For one - not a set. Ouch.$15 if you avoid eBay and buy direct from scopemeterrepair.com

author: coromonadalix
author_rank: Super Contributor
timestamp: January 20, 2025, 11:13:18 am
content: yessadly .... only thing available as a set are the battery contacts terminals, now they have been cloned and all of them are available single or in kitsfor the 189 i had, i was lucky in the past to order them directly at Fluke USA but was expensive 45$ a kit, special thread screws ... and other case parts ...now ? ...

author: Zamagen
author_rank: Newbie
timestamp: January 20, 2025, 10:00:37 pm
content: I saw the parts on EbaySo far I've repaired the damaged springy contact with a bit of solder, carefully reassembled the meter, and it seems to work.I feared the solder would have increased the resistance and skewed the measurements, but Ohm/Voltage values seems to be unaffected.Will see if it lasts, if not I'll try to have a new set of contacts manufactured.Thanks for the help!