20EZV exploding cap!

kilgers

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Haven't fired this monitor up in two months because the last time I did it sounded like a firecracker going off. Just got a cap kit for it, installed everything, fired it up and...about three seconds later c472 blew up. Any ideas?
 
Caps normally only explode if they are installed backwards...

Unless the board is screened wrong, it was in the right way. This was my first time doing a cap kit, so I checked every one three times before I decided to call it good.

The same cap had exploded the first time I turned it on, also.
 
Unless the board is screened wrong, it was in the right way. This was my first time doing a cap kit, so I checked every one three times before I decided to call it good.

The same cap had exploded the first time I turned it on, also.


The fact that two caps exploded is what has me concerned about the cap being in backwards. Since you need to pull the board anyway you can look at the legs and see where they go and use the schematic to determine if the cap is positioned correctly. I haven't heard that there is a screen print problem with these boards but I wouldn't be surprised to find out there is one.


Another possibility: the flyback is shorted, but that cap is rated for a fairly high voltage so I don't know if that would lead to this.

My suggestion is to pull the chassis and test all components leading into and out of that cap to see if one is damaged causing the problem. Of course, it is possible that someone else prior has seen this problem and they will chime in any minute to point you in the right direction.
 
Haven't fired this monitor up in two months because the last time I did it sounded like a firecracker going off. Just got a cap kit for it, installed everything, fired it up and...about three seconds later c472 blew up. Any ideas?

I believe this problem was covered in a back issue of Star Tech Journal.
 
Hantarex monitors have a lot of caps screened wrong, so maybe also the sanyo has one or two.

The rule is: never trust on what is written (on schematics or on the monitor itself) but on the "one day was working" component removed
 
pic.

Couldn't find my camera, but here's a pic from my phone. Pretty much nothing left to identify.

I have three others to do, so it might be a week or two til I get back to this one. (Also, I'm sick of looking at it now.)

Thanks for the input, guys.
 

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From the looks of it it was C467 that blew....not C472.
Topside of the chassis appears to be screened properly, negative lead goes directly to TP431.
Maybe pull D454 and see if it is shorted.
 

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