Repairing Fluke DMM's - Page 1
Forum section: electronics / repair

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: February 11, 2014, 12:52:00 am
content: Hi I've had a little Fluke 79 seies II for just about everrrr (1993 I think) Well it got dropped a few times, and even though the case is cracked around the corner of the LCD window, it continued to work just fine.Well a couple years ago I got stupid, and it got hooked on to a Capacitive Discharge Ignition and blasted it with HV spikes. Well I just put it aside until recently. Got the Service Manual online (but not from FLuke). Discovered R1 was open a 1K 2Watt 1% fusible resistor right at the input terminals. I have temporarily installed an 1/8 Watt 1% until I get some better resistors from Mouser.Fluke apparently is on a steep decline in the repair parts. You really cannot get anything from them! Iwould like to get anew top case and LCD window. I guess it's ebay or nothing.

author: retiredcaps
author_rank: Super Contributor
timestamp: February 11, 2014, 04:25:20 am
content: Quote from: SoundTech-LG on February 11, 2014, 12:52:00 amI periodically look from time to time, but I haven't see a 1k 2W fusible 1% resistor anywhere.Modemhead's blog entry suggests an alternative (NTE F2W210).http://mrmodemhead.com/blog/fluke-87-fusible-resistor/QuoteEbay is probably your own option. I don't know when the 79 III was discontinued, but parts are likely all gone.

author: retiredcaps
author_rank: Super Contributor
timestamp: February 11, 2014, 04:29:59 am
content: Quote from: SoundTech-LG on February 11, 2014, 12:52:00 amUsually, I'm pretty good at finding these things, but where did you find a service manual for the 79 III? I found one for the 79 II, but not III. Working in the garage at -15C today as numbed my brain I think?

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: February 11, 2014, 04:44:27 am
content: Hi,Sorry brain fade the meter was not in front of me... series IIIt compared quite favorably against the 189, an 87, and a bench-top Agilent meter on 3.5000 volts within 1mv

author: retiredcaps
author_rank: Super Contributor
timestamp: February 11, 2014, 05:29:34 am
content: Quote from: SoundTech-LG on February 11, 2014, 04:44:27 amGetting a new series 79 II front case and lcd window from Fluke in 2014 is highly unlikely. One person on ebay sells parts from meters he cannot or will not repair, but his asking price for very poor condition parts is high.Let's see a picture of the 79 II damage?edit: fixed some typos.

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: February 11, 2014, 10:20:27 pm
content: I actually spent considerable time buffing out the LCD Window with 3M wax. It really did a great job! Then, carefully used black Duct tape to cover up the top corner. I am pretty impressed with the overall cleanup. Amazing little meter that's over 20 years old!Love the range of capacitance it can check...and photos ...

author: retiredcaps
author_rank: Super Contributor
timestamp: February 24, 2014, 07:16:27 am
content: I didn't see your edit where you snuck in the photos.Anyway, if you don't mind the mismatch model number lcds, there are 2 listed on ebay for $4.99 + free ship.http://www.ebay.com/itm/321332706467http://www.ebay.com/itm/321332704860I have no affiliation or experience with the seller, so caveat emptor.

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: February 26, 2014, 09:24:23 pm
content: Yeah, I didn't think it was worth bumping it back to the top, like this.I ended up getting a model 77 off the bay and gutting out the front case (swapped off the decals, broke off two tiny tabs near the battery partition), and found a 79 II LCD window kit. So the 79 is pretty much fully restored. The 77 is looking like the 79 did. No biggie. It'll fit in my motorcycle bag. The 77 was pretty far off CAL. All are spot on now.