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Electronics => Repair => Topic started by: bogdan2014 on July 05, 2019, 12:12:38 pm

Title: DAB water pump inverter repair
Post by: bogdan2014 on July 05, 2019, 12:12:38 pm
I'm trying to repair a DAB "esybox" water pump that shows an error which according to the manual is indicating one of the following issues:

- blocked motor (excluded)
- fault on the IGBT drivers or final stage
- firmware problem
- output current reading circuit issues (soldering joints, components etc)

According to the owner, the pump stopped working after the mains supply went down for a while.
I started by checking the transistors and the gate driving portion up to the gate drivers (IRS21084). Apart from a strange diode configuration, everything seems ok.
The current measuring section is done with 0.1ohm resistors and what seems to be LM393 comparators. The resistors are fine.
I'm tempted to replace the driver ICs since there's no way of checking them anyway, and those are the most sensitive parts out there. But I want to eliminate anything else as much as possible.