ESCORT 3146A 5.5 BENCH MULTIMETER CURRENT FUNCTION STOPPED WORKING

[junggwok]

Hey

I HAVE 2 BENCH MULTIMETERS, JUST REALISED TODAY THAT MY ESCORT 3146A 5.5 BENCH MULTIMETER, THE 12A CURRENT FUNCTION STOPPED WORKING AT ALL, mA CURRENT WORKS FINE. COULDN'T FIGURE OUT THAT'S WRONG WITH IT. TRIED IT WITH 3 POWER SUPPLY, IT JUST SHOWED NOTHING. I OPENED THE CASE UP BUT, AS FAR AS I CAN TELL EVERYTHING WORKS FINE. AND YES BOTH FUSES ARE NOT BLOWN.

HOPE SOMEONE CAN SHARE SOME LIGHT ON THIS.

THANKS

[Rerouter]

first. try turning capslock off..

secondly, as dumb as is may sound have you moved your probes into the amps terminal, mA is usually tied to voltage so it doesnt matter, but amps generally has its own terminal,

[junggwok]

first. try turning capslock off..

secondly, as dumb as is may sound have you moved your probes into the amps terminal, mA is usually tied to voltage so it doesnt matter, but amps generally has its own terminal,

Thanks for your input, I am sorry to say this but it was really dumb advice. I actually check even the PCB trace on the board and also current shunt seems to be in good condition. And yes I did put the probe in the amp jack, what I meant was mA jack is working fine, meter is showing measurement, but the 12A jack is not working. Couldn't just figure out why.  One thing my PHD in electrical engineering has taught me is to put probe in the Amp jack for measuring current. Please don't be offended, you don't know me I understand.  But do you think a person with two 6.5 digital bench multimeters at home will ask questions on eevblog and not knowing put probe in amp for measuring current.

[David_AVD]

Steady on with the "dumb advice" reply.  People with fancy gear ask questions all the time.  Sometimes they have overlooked something simple.

[David_AVD]

By the way, does the meter actually pass any current when you're using the Amps range?

[junggwok]

Once again I am sorry about what I said. But I have checked everything, I checked fuse are working but I replaced them anyway just to see if that helps. Still no current measurement. I trace PCB and I couldn't find any short.

Don't be offended about what I said, it is just frustrating at the moment

[junggwok]

By the way, does the meter actually pass any current when you're using the Amps range?

Yes it does, I set a current limit on my power supply, the supply was showing amp are passing
through the meter

[junggwok]

Found the error on the pcb trace

[David_AVD]

Maybe post a picture of the issue and solution in case it helps someone else?

[robrenz]

Found the error on the pcb trace

Broken sense connection to the shunt?

[junggwok]

I will try once I am finished repairing it. I actually just noticed one of PCB traces to the current shunt was a bit worn out. Just put a bit of solder on the trace and it worked, simple as that. It was still strange as current was passing through but the meter it just didn't show any measurements.

[junggwok]

Found the error on the pcb trace

Broken sense connection to the shunt?

No actually, that one of first things I checked. It was just pcb trace connecting from jack cable to current shunt. I have say it was really strange
it doesn't make any sense. Oh well it is working now, might take it to work tomorrow and let my guys to figure what actually went wrong

[nukie]

You might want to recalibrate your meter after that 'modification'.

[gboutique]

This post is old, but it is important to say that the Agilent U3402A (90% Escort 3146A), presented the same fault, and it was corrected in the same way. Thanks..!!