I'm an untrained hobbyist trying to fix this motor driver circuit and was looking for some guidance or help with troubleshooting, or reconstruction. The circuit is from a handheld vacuum cleaner that stopped working.
The device itself isn't very old, the battery pack and charging function seem to be working fine: the batteries measure at 19.00 V and are keeping their charge steadily after days. The charging indicator LED (on the other side) lights up to indicate charging when plugged in. The mechanical switch works fine (verified by continuity test and proper voltage measurement when switched) and the motor itself works fine when the circuit is bypassed and is directly powered.
My best theory is that the C6 capacitor (top, near the FET) exploded. There is what looks like debris all around where C6 should probably have a surface-mounted capacitor. There are no schematics of the proprietary board and I can't see any traces on the other side that would provide additional information.
R23 measured at 99.4 Kiloohms, R24 at 0.478 Megaohms, R25 at 0.465 Megaohms. There was continuity between the upper FET lead (source?) and bottom of R25. I'm assuming this board uses a common FET-PWM circuit that I'm obviously not familiar with but had hoped someone would recognize.
My question is both specific and yet open-ended. First, whether this is possibly the right cause of malfunction (a missing C6)? If so, how would I estimate values for a suitable replacement candidate?
And of course, if not, what should I be looking into to determine cause of the problem? Any pointers, help or knowledge are very much appreciated.