Need PCB layout for Metex M3900 digital mutimeter

Thread Starter


Joined Nov 20, 2017
I'm repairing a broken Robin multimeter which has a Metex M3900 board in it. The problem is corrosion on the PCB around the on/off switch which has caused the PCB pads and tracks to be unreadable. I have the basic schematic but the problem area is where the -V battery supply comes in and where a second board attaches with a row of pins. It is difficult to trace all the -V lines back from the schematic so I can't easily tell which pads need to be reconnected to replace the corroded tracks. From the attached I can't tell which of the connecting pin, the -V supply and the 260K resistor are connected together.
Does anyone have a PCB layout for this meter? Or if they have the meter are willing to take it apart and photograph the problem area.