Author Topic: Keysight U1281A faulty from new  (Read 270 times)

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Offline targit

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Keysight U1281A faulty from new
« on: September 16, 2018, 07:31:50 pm »
Hi, Thought I had a good result with getting a new U1281A off eBay (Singapore) for a little over $400AUD, and when it arrived all brand new in the box all seemed well.
Reading the manual like all good boys do, and playing around with the setup, I noticed every now and then it would show OL on the DC range, even with no leads connected.
I had a play and it seemed to be normal most of the time, then I was trying out the resistance range and it started showing random resistance figures in the KiloOhm range for a known good lead across the inputs. I opened it up and had a look under the microscope and here's what I found..

A probe with my trusty old Fluke 85 shows this is open circuit between the pin and the via next to it, and the data sheet says this is the inhibit pin of the 4053 multiplexer.
As I don't have a circuit diagram, I can't be certain if this is the fault I am seeing so I dont want to void my warranty (if I haven't already) by "fixing" this joint. It is very tempting though.....

Offline Synthtech

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Re: Keysight U1281A faulty from new
« Reply #1 on: September 16, 2018, 07:34:30 pm »
Well spotted!

Online TheSteve

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Re: Keysight U1281A faulty from new
« Reply #2 on: September 16, 2018, 07:58:08 pm »
You've already got it open, just solder that pin. If it fixes it great. If it doesn't I don't see the big deal having it replaced under warranty.
This assumes you're comfortable with soldering small parts, if you're not comfortable use the warranty.

Offline Muttley Snickers

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Re: Keysight U1281A faulty from new
« Reply #3 on: September 16, 2018, 08:27:29 pm »
Keysight read this forum so before touching up the joint I would probably just wedge a sliver of aluminium foil or similar conductive material in between the pin and pad if there is a gap, then check the meters functionality again. If this doesn't fix the problem then enter the meters details on the Keysight Support page to see if the meter is still within the three year warranty period. Keysight are extremely good in regards to warranty and support, they looked after us well after the warranty had expired so I only have good things to say about them.

Keysight Service.
« Last Edit: September 17, 2018, 07:48:16 pm by Muttley Snickers »
One smart cookie, better make that two for good measure.
The following users thanked this post: targit

Online perieanuo

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Re: Keysight U1281A faulty from new
« Reply #4 on: September 17, 2018, 06:11:24 am »
put someone with skills in soldering nobody can notice this.
life is short :)
regards, pierre

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