E-bike battery charger repair

Thread Starter

Andrew Amundrud

Joined Jan 9, 2018
4
Hi there,

I have an e-bike battery charger with a blown capacitor. I replaced the capacitor and after 1/2 hr charging it blew again. Need help trouble-shooting.

Thanks,

Andrew
 

Thread Starter

Andrew Amundrud

Joined Jan 9, 2018
4
Could it be the square looking thing sitting next to the capacitor over-heating? There is an aluminium heat sink tied to it - you can't see it in the photos as I've removed it to get a look at the capacitor. I put some new thermal paste on it and tried improving the connection to the heat sink. I've also gone ahead and ordered a new charger from China for $12 (sorry Trump).
 

Dodgydave

Joined Jun 22, 2012
8,601
Looks like the capacitor is the main smoothing cap for D10 ( twin diode package), so the feedback circuit for the opto-couper isn't working, and the smpsu is giving out full voltage. Measure the voltage across the capacitor.
 
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