View Single Post
  #3   Report Post  
Franc Zabkar
 
Posts: n/a
Default

On Tue, 16 Aug 2005 11:13:11 +0100, "N Cook" put
finger to keyboard and composed:

Jou Jye 300AP
Blown 5 amp mains fuse
There is a 1/2W resistor between the common point of the 2 x 200V mains side
electrolytics
and one of the 2 leads , high V side of the large isolation transformer,
marked on pcb as R5 now reading 98 ohms
Overheated and probably had a brown and a red band somewhere in the value.
Covered with some 125 degree shrink-sleeve that has charred. This was to
protect against touching other parts but this R was on end and lead doubled
back and presumably the bang was the long lead shorted to the other barrel
end of the R as severe tell-tale smoke 'jet-trails' at that point, no
ceramic spacer or anything .

Anyone hazard a guess what the original value might be. ?
The 2 main 2SC2625 and 200V electrolytics seem OK.

Parallel to the 4 wires of the mains side bridge rectifier is a small
sub-circuit
with (2S?) K2645 and a L8561 8 pin IC, is this all a crow-bar circuit to
knock out the mains fuse?


This smaller circuit is probably the +5VSB standby supply.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.