GDM-8251A Intermittant reset

[negativ3]

Hi,

I have the GDM-8251A DMM which has developed a fault in the last day or so. Around every 2-3 minutes it does a power on reset cycle, doing the self-tests then displaying the measured voltage (3.3V currently) correctly..

This happens at different mains power outlets, and with or without a voltage being measured.

Display at power-on:

V2.30
PARA:DEF RECALL
RS232 IO

All seems to be default as per the user manual.

No codes or anything to indicate a fault, just a few relay clicks, display refresh and back to measurements.

Does anyone have any insight before I tear it to bits?

Thanks
Andy

[odium]

hi,

Maybe you have some thermal problem which triggers protection circuit.
Anyway,  before getting down the rabbit hole, you can try this basic test, save
user settings to default boot config and see if the device stops rebooting.
this will allow you to discard potentially corrupted boot settings.

doc :
https://www.gwinstek.com/en-global/download/downloadFile/9122

hope it helps.

cheers.

[shakalnokturn]

2-3 minutes sounds a little long for corrupt EEPROM settings, thermal sounds more likely.
Considering it has a compact SMPSU I'd start there, next suspects would be low voltage linear regulators for CPU, FPGA... if there are any.

[negativ3]

Apologies for the late response, life took over for a while...

Ok, after cracking the case, this meter only has a single output 5V PSU from meanwell. I measured the output at the meter PCB and it was dropping all the time, from around 4.9 to 4.6V before I stopped measuring.

Measuring at the PSU output gives a solid 4.975V.

So... used a couple drops of Deoxit grease on all the contacts, and so far no resetting. Hoping for the best.