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Electronics => Repair => Topic started by: LilJohn2 on June 28, 2024, 06:45:34 am

Title: ANENG AN8008 noisy and offset readings
Post by: LilJohn2 on June 28, 2024, 06:45:34 am

Hello, I have an ANENG AN8008 that started to misbehave. The voltage measurement is all over the place when the leads aren't connected to anything, but when I join them, the readings jump between 0 and 300mV every second.
When I'm measuring eg. 12V battery I get some reading offset. 12V on battery shows as 13V something, and when I flip the leads I get -10V something.
I tried resoldering SMD components but it didn't help. Capacitors looks alright, no discoloration, no cracks. It wasn't abused or modded in any way. Should I change all the caps on the board?

Title: Re: ANENG AN8008 noisy and offset readings
Post by: Kleinstein on June 28, 2024, 11:25:51 am

It is unlikely that the capacitors are bad - the AN8008 is not that long available for the caps to go bad. With low power the capacitors don't even get warm from the power losses.
A first point to check is the battery. Otherwise a repair is likely not worth it, if a careful visual inspection does not show a problem. A bad solder join is the main candidate for a failure.

Title: Re: ANENG AN8008 noisy and offset readings
Post by: jzx on June 28, 2024, 01:44:27 pm

Clean also the conmutator contacts, sometimes the grease gets into the contacts.