intelligent pulse repair charger broken need advises for repair

Thread Starter

LAOADAM

Joined Nov 21, 2018
826
I bought an intelligent pulse repair charger: https://www.ebay.com/itm/322598595329?hash=item4b1c5feb01
Broken in a sudden, and checked that there are four 1200 Ω resistances burned or some of them burned. The attached picture shown the front side where can easily find the destruction position, and the backside obviously shown the cause of destruction, and there are 4 pairs of holes after remove the damaged resistances. Can I just insert 4 resistances into the 4 pair holes? or any good suggestions?

WANLESANHE_post.JPG

Thanks
 

MisterBill2

Joined Jan 23, 2018
13,164
I see no obvious cause of destruction, only a lot of damaged areas, although it may be that there are solder bridges, that part is not clear.
Parts very seldom "just burn up" because they are bad, almost always there is some other condition that leads to the destruction. So usually just simply replacing fried parts will result in more fried parts, unless the parts that caused the failure are also replaced.
 

MisterBill2

Joined Jan 23, 2018
13,164
is the obvious signs causing the damage from too much current passing through? The globs of solder is typical of cheaply made devices and looks normal.
It looks to me like the glob of solder in the one tagged "back" is gone in the one marked "clean", and it appears to have been shorting three pads. But the different views make it hard to compare between before and after.
 

narkeleptk

Joined Mar 11, 2019
548
I see that glob "technique" used all the time tho on low end builds so I'm not sure it wasn't by design.
Looking at it again I think maybe the globs got into that trace that is coming down the middle and caused it.
 

MisterBill2

Joined Jan 23, 2018
13,164
OR did somebody "working" on the device do a poor soldering job? I have seen work by folks claiming to be good techs that would get an F- on the first day of soldering class. Ralph G., to name a name.
Or maybe it was an "as built" flaw. Those do happen.
 

Thread Starter

LAOADAM

Joined Nov 21, 2018
826
WANLESANHE_post.1.jpg Thanks to all.
I don't have any idea about the board, here attached the picture of a good one, maybe helps to figure out how the soldering should be, sorry I'm no good at electronic stuff.

Thanks.
 
Last edited:

bwilliams60

Joined Nov 18, 2012
1,437
Would this unit run on 120V mains voltage? If so, perhaps you can clean up the board, make the necessary repairs and replace the parts that are bad, and then start it up using a DBT and isolation transformer to see if the unit is shorted. As mentioned earlier, it probably had a lot of current go through that section of the board and the problem is still there. Plugging it back in full will just end with the same result. You have some board damage there that will need some attention. By the looks of your last screen shot, you are in for a lot of work. Personally, I would go around and clean up all the solder blobs and see if you can clean up some of the mess. If you are not familiar with working with the necessary voltages, I would pass it along to someone that does.
 
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