What part makes my multimeter beep?   - Page 1
Forum section: electronics / general

author: silviasol
author_rank: Regular Contributor
timestamp: June 09, 2017, 07:01:28 am
content: I replaced the battery wiring on my fluke multimeter and not it does not beep on ohm setting. This sucks because that is all I really use it for, I know I should have more use of it. What part is the speaker or whatever beeps. One of them has corrosion but I would think that just opening it would not have made it quit working?This link has three pictures, if it does not work please let me know.http://imgur.com/a/gZdmd

author: kalel
author_rank: Frequent Contributor
timestamp: June 09, 2017, 09:04:46 am
content: Quote from: silviasol on June 09, 2017, 07:01:28 amOddly I don't see a beeper on your images, but there are so many experts here that possibly a reply was already written by someone knowledgable before mine gets posted.On Fluke 117 Dave's image:https://www.flickr.com/photos/eevblog/sets/72157626631973147/you can easily see the piezo on the right of the image (the black box with a circular hole). But maybe some models have a tiny version that is more difficult to see.Just noticing, are there some missing fuses on the multimeter?

author: MarkS
author_rank: Unknown
timestamp: June 09, 2017, 09:05:27 am
content: There isn't anything resembling a speaker or buzzer on that board. I'm willing to bet the speaker is glued to the housing with spring leads contacting pads on the board. More pics are needed.

author: Nusa
author_rank: Super Contributor
timestamp: June 09, 2017, 10:33:56 am
content: For future reference, it's REALLY helpful if you mention the brand and model number of the meter when asking such questions. I'm going to guess it's a Fluke 26, based on the metal can for the processor, 1997 date on the board, only two buttons and the old wafer-type rotary switch.The beeper is not supposed to operate in the low-ohms range. Try switching ranges with the range button before you call it a hardware problem.The beeper is embedded in the back cover. Its contacts are right next to the hole for the rotary switch.

author: CJay
author_rank: Super Contributor
timestamp: June 09, 2017, 10:43:12 am
content: The beeper is probably mounted on the rear case and will probably be a silver/brass disk with a strip of plastic over it, on that strip there should be two black conductive rubber 'pegs' that contact the disk and the PCB when it's all connected together.

author: ModemHead
author_rank: Frequent Contributor
timestamp: June 09, 2017, 01:14:23 pm
content: Visual aid.

author: kalel
author_rank: Frequent Contributor
timestamp: June 09, 2017, 01:23:24 pm
content: Quote from: ModemHead on June 09, 2017, 01:14:23 pmIn such designs, is it possible for these contacts not to connect properly when closing the case?

author: CJay
author_rank: Super Contributor
timestamp: June 09, 2017, 01:32:55 pm
content: Yes, it's also possible the rubber pegs have become dislodged and lost.

author: ed_reardon
author_rank: Regular Contributor
timestamp: June 09, 2017, 05:46:45 pm
content: 'Yellow button' and put it in continuity mode?Not sure on this meter, my ancient mk1 85 has a 'buzzer' button to switch it on and off. My recent 87 I'm certain needs putting in to continuity mode?

author: silviasol
author_rank: Regular Contributor
timestamp: June 10, 2017, 12:09:19 am
content: Quote from: ModemHead on June 09, 2017, 01:14:23 pmOk I though that might be it on the case but didn't think it would connect to the board. Was there a spring or something that could have fallen out or should I keep repositioning it until I can make it beep?The model is Fluke 79 III

author: MarkS
author_rank: Unknown
timestamp: June 10, 2017, 12:31:25 am
content: Pictures, dude. We simply cannot answer without seeing the parts involved.

author: Nusa
author_rank: Super Contributor
timestamp: June 10, 2017, 01:10:51 am
content: Models 26 and 79 are the same meter. For some reason Fluke sold it under two model numbers.I'd unsolder those battery wires and put them back on the front side of the board. It's possible they are thick enough to prevent the board from snugging up to the beeper.Also wouldn't hurt to clean the contacts with a Q-tip and alcohol, although they look ok in your picture.Can't say about the beeper side. No picture.

author: ModemHead
author_rank: Frequent Contributor
timestamp: June 10, 2017, 02:05:42 am
content: No springs on this series, just the little black conductive buttons.Quote from: Nusa on June 10, 2017, 01:10:51 am+1 on both of those ideas. I've taken apart a few of these, never had a problem with the board registering into the correct position to make contact. There's very little slop.

author: silviasol
author_rank: Regular Contributor
timestamp: June 14, 2017, 02:44:44 am
content: Human error. Both times opening it I put electrical tape over those contacts to hold the new battery wiring in place. The speaker contacts are some kind of conductive rubber that press up against the solder joints. Works great now.

author: kalel
author_rank: Frequent Contributor
timestamp: June 14, 2017, 12:28:08 pm
content: Quote from: silviasol on June 14, 2017, 02:44:44 amHappy to hear that. Enjoy your now fully functioning high quality meter.

author: tooki
author_rank: Super Contributor
timestamp: June 16, 2017, 11:03:52 pm
content: Quote from: Nusa on June 10, 2017, 01:10:51 amI may have found the answer, sorta.I was just browsing an ancient magazine (Nov 1986 Radio-Electronics), and on page 7 (PDF page 9), there's a reseller ad for Fluke meters, and it states that the 21/23 add 6kV transient overload protection over the 75/77. It also mentions the DC current accuracy being slightly lower on the 21/23. So I guess they were the "safety" versions. But by 1990 (the date of the earliest user guide revisions available on fluke.com), the specs were identical. Presumably, with government contracts and the like specifying specific models, they just kept making the same item with two color cases.