Help with fluke 87 iv repair - Page 1
Forum section: electronics / repair

author: dalle3
author_rank: Contributor
timestamp: March 24, 2021, 11:37:13 am
content: Hi , alllike many users here i have bought used broken fluke 87 iv , outside/ really abused conditionbut after reading many posts from this forum have read out how it should to be when everything works .This one is unfortunately got some kind of electric shock , i have checked: movs are ok , fusible was 3.3k ohms ,have replaced with OHMITE OY102KEit still reads wrong valueson dc 1.5 volt aa battery shows 3.23then after replacing fusable now is 2.225still no good ,on ohms settings shows 0L if i try to measure something it begins to measure and then stops on 0L and not responding anymorehave noticed one missing blown smd resistor on pcb i need help from someone who has 87iv or 187 and can measure-check component to indetify what i need to buy to replace on mineSadly previous owner removed fuses together with carrierHere are few pics from device and pcbCheers

author: bd139
author_rank: Super Contributor
timestamp: March 24, 2021, 02:02:57 pm
content: Looking at other pictures it looks like the same grey SMD part missing that is above the 100k resistors on the right. Is it an SMD fuse? I’d measure across the ones above there and see if it’s short or something. If it is just jumper the pads for now.

author: dalle3
author_rank: Contributor
timestamp: March 24, 2021, 02:17:34 pm
content: It is smaller than other two, those two are 100k ohmI have looked on pics from other members here 87 iv and 187it is smallerThanks

author: perieanuo
author_rank: Frequent Contributor
timestamp: March 24, 2021, 03:57:53 pm
content: recalibrate, once I droped my fluke 110 and lost calibration, don't ask why he lost itafter basic recal, it works -almost- as before, only diode tester is kinda off the track (show lower voltages, but for testing diodes/transistors if the junction is ok or not it's enough)

author: dalle3
author_rank: Contributor
timestamp: March 24, 2021, 04:17:08 pm
content: Will do but after i find and solder missing partThanks

author: retiredcaps
author_rank: Super Contributor
timestamp: March 24, 2021, 07:57:49 pm
content: Quote from: dalle3 on March 24, 2021, 11:37:13 amDid you check the grey PTC above the fusible resistor? It should be around 1 to 1.5K ohm. Did you check the yellow spark gap? It should measure open resistance?When you say the MOVs are okay, what reading did you get?

author: floobydust
author_rank: Super Contributor
timestamp: March 24, 2021, 08:47:24 pm
content: The missing part is a ferrite bead, the meter will not give good readings without it. For troubleshooting, you can jumper (short) it out.I believe it is Fluke 944645, ferrite bead 60Z@100MHz,6ADC,10mOhm, size 1806 [4516 metric].Murata BLM41PG600SN1Dand alternate Würth742792410

author: dalle3
author_rank: Contributor
timestamp: March 24, 2021, 08:54:51 pm
content: Have checked movs on pcb and then desoldered just to be sure, on my good 87 iii both shows 0L will check ptc when i back home (I'm still at work), other components and write value here

author: dalle3
author_rank: Contributor
timestamp: March 24, 2021, 08:57:52 pm
content: Big thanks for info about missing part will do jumper to test values and let you know how it was

author: dalle3
author_rank: Contributor
timestamp: March 25, 2021, 12:23:42 pm
content: Hi ,have checked ptc 1.150 k ohm, two movs upper 0L , lower desoldered 0L, soldered 17,50 m ohm , yellow spark gap shows 0L

author: dalle3
author_rank: Contributor
timestamp: March 25, 2021, 12:52:40 pm
content: thanks for tip have tried with jumper dc is wrong like excepted but now is ohm reading work without any errorI must buy from e.ay wurth elektronik, murata is hard to find, all stores here sell only to firmsNow just to find where to get fuse holder and fuses .I'll let you know when I get and solder the ferrite bead.

author: floobydust
author_rank: Super Contributor
timestamp: March 25, 2021, 08:37:36 pm
content: Who takes out the fuse clips? That seems strange.The 87V fuse clips are:Fluke 707190, Bussmann/Eaton 707190.Fluke 659524, Bussmann/Eaton 659524.Mouser USA has them in stock- as specialty Fluke parts. Might find the similar part here:Eaton Fuse Clipshttps://www.eevblog.com/forum/repair/fluke-189-fuse-clip-replacement/

author: dalle3
author_rank: Contributor
timestamp: March 25, 2021, 10:18:35 pm
content: Believe me i felt same when i got package and opened battery traysomebody took out the fuses ok, maybe tried repair or something else... But clipsAnyway i hope mouser sell parts to everyone shipping is 20€I will order clips and I'm unsure about ferrite bead on mouser site description says WE-CBF 1806 1000MHZ 120Oh,but on specification 60 ohms

author: bd139
author_rank: Super Contributor
timestamp: March 25, 2021, 10:30:59 pm
content: It may be an attempt to hide previous criminal activity. This is a Fluke 25 I received. The fuse was soldered in as the clip had broken off. And yes the switch wafer had melted too.

author: dalle3
author_rank: Contributor
timestamp: March 25, 2021, 10:51:22 pm
content: People do sometime silly and dangerous thingsI will complete this meter like it should beFuses have found here bosman 440mA 9€ and 11A 15€Not to expensive but original

author: dalle3
author_rank: Contributor
timestamp: May 10, 2021, 02:48:21 pm
content: Regards to all ,Finally all the parts have arrived and I can proudly say that the multimeter works just like new nowI would like to thank all the members for their help in identifying the right parts and the right advice on how and what to check.This thread can be closed nowCheers