Fluke 8000A range-switches - Page 1
Forum section: electronics / testgear

author: wiss
author_rank: Frequent Contributor
timestamp: December 18, 2013, 05:39:56 pm
content: HiHas anybody fixed ever the switches on an old 8000A?"S9E" fails to make contact in the off position, that is for the 20 kOhm range, because of this the 200 end 2k ranges becomes 200k and 2M.Jonas

author: wn1fju
author_rank: Frequent Contributor
timestamp: December 19, 2013, 03:50:54 pm
content: Have you tried the obvious first? Namely, stand the (open) unit up on its front panel and squirt a liberal dose of contact cleaner in the opening at the rear of all the switches. Let it drip down for a few seconds and then exercise each switch a couple of dozen times. The switches are usually OK, just dirty.

author: wiss
author_rank: Frequent Contributor
timestamp: December 19, 2013, 05:13:06 pm
content: No, that's the only I've not tried.The switch works for a while, perfectly, and then stops working completely for a while, switching it seems not to work, and sometimes it seems to work a little bit (readings of 40 to 80 ohms for a 90 ohm resistor).I will try to find some of that stuff.Jonas

author: wiss
author_rank: Frequent Contributor
timestamp: February 05, 2014, 02:09:37 pm
content: I sprayed the range-switches with some "Electro-clean" the other day, result: now all of them behave wackoThis one goes into the archive-shelf for spare-parts for when I pick up another one with a minor problem, like fried logic or something...

author: wn1fju
author_rank: Frequent Contributor
timestamp: February 05, 2014, 04:21:57 pm
content: Often times contact cleaner needs to dissipate or dry out a little before things seem to work, especially if you have flooded theswitches as I previously suggested. Wait a day or two and see if it behaves.

author: edavid
author_rank: Super Contributor
timestamp: February 05, 2014, 05:05:00 pm
content: After it dries out, try resoldering the relevant switch pins too.If that doesn't work, check that switch for unused contacts that you can use in place of the bad ones... I have fixed some 8600A switch issues that way.

author: wiss
author_rank: Frequent Contributor
timestamp: February 09, 2014, 05:04:06 pm
content: Tried again today, the switches perform really bad, much worse than before I "fixed" them...I think that spray left residue all over...Cleaned again with another brand now, will let it dry until tomorrow and we'll see...

author: wiss
author_rank: Frequent Contributor
timestamp: May 26, 2014, 09:28:28 pm
content: Just had the same problem with a HP 3465A, used a spray which according to the label only contains 2-Propanol ( = IPA )Worked perfectly!

author: xwarp
author_rank: Frequent Contributor
timestamp: May 26, 2014, 11:39:22 pm
content: Try a switch cleaner with some sort of lubrication in it such as DeOxit.

author: wiss
author_rank: Frequent Contributor
timestamp: May 27, 2014, 05:35:31 am
content: Will the lubricant be guaranteed to be a very good insulator?The HP is a high impedance instrument.

author: edavid
author_rank: Super Contributor
timestamp: May 27, 2014, 03:34:27 pm
content: Did you ever get the 8000A working again?

author: wiss
author_rank: Frequent Contributor
timestamp: May 27, 2014, 05:57:23 pm
content: No, all switches stopped workin, I gave up. It's not that interesting to me, the step-up transformer is quite noisy at a few kHz.