Fluke 88V shows 4 dashes  - Page 1
Forum section: electronics / testgear

author: stanward
author_rank: Newbie
timestamp: March 29, 2021, 07:02:47 pm
content: Hello,I have a barely used Fluke 88V that suffered a leaking 9V battery. Repaired that situation, even used electronics contact cleaner and heat gun to dry everything up. Now my meter shows 4 dashes on the resistance, diode test, A, uA settings.V and mV settings do not show this.Here's a doozy, if I leave the multimeter in the setting that shows the 4 dashes, after a few minutes, it will start working again, and will work great for the next few hours, until I power off the meter and try to use it again. Which I will have to wait a few minutes on that setting if I want to use it.

author: AVGresponding
author_rank: Super Contributor
timestamp: March 29, 2021, 07:08:15 pm
content: Does it give credible readings in those positions, once it has woken up?

author: stanward
author_rank: Newbie
timestamp: March 29, 2021, 07:10:49 pm
content: Quote from: AVGresponding on March 29, 2021, 07:08:15 pmThank you for your quick reply!Yes, I have used it in those settings to test, and the values shown seem to be credible.

author: AVGresponding
author_rank: Super Contributor
timestamp: March 29, 2021, 07:50:07 pm
content: That more or less eliminates the front end, then.Looks like it could be some remaining contamination in the input selection circuitry that connects to the meter controller asic, maybe part of a debouncing circuit has some conductive schmoo in it making it tricky for the controller to see what function has been selected?Might be worth giving it another clean, I recall a friend with a weird problem with a bench DMM after a memory battery leak eventually cleared only after about 3 or 4 thorough cleans!

author: retiredcaps
author_rank: Super Contributor
timestamp: March 29, 2021, 08:26:59 pm
content: Quote from: AVGresponding on March 29, 2021, 07:50:07 pmI agree with the above. Use generous amounts IPA 99% and use a clean toothbrush to gently scrub the entire PCB. The battery juice may have wicked its way up and into components and not visible to the naked eye. Dry thoroughly before using.After that, put in a reminder into your calendar to check the battery every 6 months. Or put in a lithium 9V battery. It costs a bit more than alkaline, but it's cheaper than buying a brand new Fluke 88V.

author: stanward
author_rank: Newbie
timestamp: March 29, 2021, 08:37:09 pm
content: Thank you for your response. You answered a question I was about to ask, whether to use 9V Lithium batteries in my DMM, and was wondering if they are more resistant to leakage. Thank you again everyone for your help!Quote from: retiredcaps on March 29, 2021, 08:26:59 pm

author: retiredcaps
author_rank: Super Contributor
timestamp: March 30, 2021, 03:53:03 am
content: Quote from: stanward on March 29, 2021, 08:37:09 pmIt's been discussed on the forum before. Search for it and you will find some info.

author: AVGresponding
author_rank: Super Contributor
timestamp: March 30, 2021, 05:38:20 am
content: My personal choice is to use Li-ion/Li-po rechargeable PP3's in my handhelds, such as these:https://www.ebay.co.uk/itm/2Pcs-ZNTER-9V-400mAh-Li-Po-Battery-5V-USB-Charging-as-6LR61-PP3-6LF22-MN1604-/322442802154