Recommendation for someone to repair HP 34401A DMM? - Page 1
Forum section: electronics / testgear

author: iXod
author_rank: Frequent Contributor
timestamp: July 29, 2020, 01:12:22 am
content: Displayed voltage is a floating value not related to the input value.Recommendations for a repair service?Thanks.

author: Kean
author_rank: Unknown
timestamp: July 29, 2020, 01:31:40 am
content: It might help if you state your location, or set it in your profile.You could of course try Keysight, while it is a discontinued model they do still provide service for it.

author: iXod
author_rank: Frequent Contributor
timestamp: July 29, 2020, 02:30:06 am
content: Profile update: Done.Thanks, I'll ping Keysight.

author: bdunham7
author_rank: Super Contributor
timestamp: July 29, 2020, 02:37:19 am
content: Quote from: iXod on July 29, 2020, 01:12:22 amCan you elaborate on that? If you connect a 9 volt battery to the leads it just reads whatever? Is this a new-to-you unit?

author: hugo
author_rank: Regular Contributor
timestamp: July 29, 2020, 02:45:14 am
content: If you feel adventurous ...https://xdevs.com/fix/hp34401a

author: coromonadalix
author_rank: Super Contributor
timestamp: July 29, 2020, 09:44:32 pm
content: Do a self test and report

author: Dr. Frank
author_rank: Super Contributor
timestamp: July 30, 2020, 01:08:51 pm
content: Quote from: iXod on July 29, 2020, 01:12:22 amWe (the eevblog community) have repaired many 34401A remotely. For this failure picture, there might be already a few possible and known root causes: front/rear switch, input relay, protection resistors.You need to test more precisely, which modes, ranges and configurations do fail.Please go through the other modes, as DCV ratio, 2W/4W Ohm, Ampere, ACV and test if that's floating also.Also check, if the rear jacks are operational.What about 10V reading in 100V range?Quote from: iXod on July 29, 2020, 02:30:06 amThis solution is BER.Frank

author: coromonadalix
author_rank: Super Contributor
timestamp: July 30, 2020, 02:21:02 pm
content: The front rear switch may play tricks, and you have an internal fuse socket near the rear terminals ... thats why as written above, you have to test all the modesThe self test may point to some problems

author: Jwalling
author_rank: Unknown
timestamp: July 30, 2020, 02:59:38 pm
content: Quote from: iXod on July 29, 2020, 02:30:06 amI'll bet it's more than a used one would cost. I wouldn't bother...An exchange is $822.https://service.keysight.com/infoline/public/product-service.aspx?laf=mya&pn=34401A&lc=eng&cc=US

author: coromonadalix
author_rank: Super Contributor
timestamp: July 31, 2020, 12:34:07 am
content: 822$ wtf? wow just buy an used working one

author: WattsThat
author_rank: Frequent Contributor
timestamp: July 31, 2020, 12:42:21 am
content: Quote from: coromonadalix on July 31, 2020, 12:34:07 amOr just pony up another $200 and buy a new 34460/1A.

author: MathWizard
author_rank: Super Contributor
timestamp: July 31, 2020, 12:49:41 am
content: So on average, if 1 of these break, how repairable are they, if you don't have a 2nd for parts ?I'm sure I'd love 1, but add on the calibration cost, tx/sh, and it looks a lot worse, than a newer model.

author: alotvac
author_rank: Newbie
timestamp: July 31, 2020, 01:36:39 am
content: Quote from: WattsThat on July 31, 2020, 12:42:21 amOr, a used 34465A directly from Keysight? $1,080.80 (with make offer, possibly another 10% - 15%)Keysight Used 34465A Digital multimeter, 6 1/2 digit, Truevolt DMMhttps://www.ebay.com/itm/Keysight-Used-34465A-Digital-multimeter-6-1-2-digit-Truevolt-DMM/174367518510?hash=item28991d2f2e:g:DvwAAOSwgJpfICWR

author: Jwalling
author_rank: Unknown
timestamp: July 31, 2020, 08:52:38 am
content: Quote from: coromonadalix on July 31, 2020, 12:34:07 amYep. And keep the old one for parts, if the OP can't fix it.