Electronic Battery Load Tester

[sprockets]

Greetings, Everyone.

I am an obvious noob when it comes to repairing electronics, I dont really know what I am doing but tend to learn by doing over time.

Anyway I am trying to figure out what I did to break these two battery capacity testers, I am pretty sure they are both from a reverse polarity being applied on accident. I have one working unit too but I cant seem to find any differences with a multimeter, but as I also stated I am pretty green.

Here is a picture of what I am working on, what would you personally look at first with what I have stated.

 

[crutschow]

Without a schematic it's near impossible to determine what might have failed.

 

[augustinetez]

At $20-$30, I wouldn't be wasting my time trying to fix it, just buy another one and be more careful about hooking it up.

For others - it's commonly known as a DTL150 150W Electronic Load Battery Discharge Tester - there's other variations of it.

 

[danadak]

Add an ideal diode to the test leads to prevent damage if reverse polarity is
applied again ?

https://www.analog.com/en/parametricsearch/11029#/

Regards, Dana.

 

[sprockets]

I already bought a replacement, it looks simple, I am sure there is a way to figure out what is wrong with it, ill try a thermal camera once I can order one, just figured knowing what I did and knowing components someone with knowledge would have an idea of what to look for. Either way thanks for the responses and ive looked for a schematic i dont think one exist. But I mean look at mend it mark, half the time he has to make up his own schematic so there has to be way to just understand what is going on and by logic figure it out, but that I figured took years and more experience I guess what I am saying is DANG MAN

 

[sprockets]

it turns on it just doesnt draw any current maybe that detail might help someone

 

[rjenkinsgb]

The first thing I'd try is test the main power device, that had the heatsink on it?