K4900 blowing fuse.

any of the other diodes in that rectifier could cause the others to fail.
 
whats the parts number of the diodes that you are using in the rectifier circuit?
 
why is there a thermistor on the pcb at position th501? it is linking the 2 ac pads causing the short. half of it is broken off. removing it gets rid of the short. is it necessary for the board to work?
 
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its a safety device. In case a massive amount of voltage hits the board it shorts and takes the hit.
 
got it plugged in, turned it on and the fuse blew again. i did hear the monitor charge for a second though. The HOT on this board is a 2sd869 and the spec sheet says this is a 5 amp transistor where the 2sd898 is a 3.5 amp. my donor board has a 898. the flowchart says to resistance check from the metal case of the HOT to ground. high is good low is bad. mine tests around 11k.

edit: an 869 is not 5 amp, its 3.5 i misread. and d501 has failed again, probably the cause of the blown fuse
 
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looks like either will work. Hmm... Something else is now wrong. Look for cold solder on the right rear corner of the board.

Did the fuse flash open or just burn open?
 
after checking some of the ceramic caps in the rectifier circuit ive found the capacitance if double what the cap should be not sure if that is important or not
and d701 has a drop if .1v in both directions while in circuit but out of circuit it has .486v drop in the correct direction and OL the other?
 
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probably not cap kit related. Did you check that back corner of the board for cold solder?
 
yes, reflowed everything in the area

consider this for a second. Whatever is causing that fuse to blow has to be of substantial size to not smoke or blow up. The HOT, the flyback, large poly caps even large diodes.

Look at them first.
 
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