Hi, Any help is great.
Still pretty new to repairing pins. Learning alot but long way to go. I have successfully brought back a system 1 solar ride following clays guide. Now I am working on my 2nd system 1 Dragon.
Here is whats going on. When I got the machine 1/4 amp sb fuse on bottom panel was dead. cr3 and cr4 diodes on power supply burnt. Small transformer had no fuses.
I did ground mods, replaced 1/4 amp slow blow, added 3 fuses per clay to small transformer, checked rectifiers on bottom panel, Re-pinned connectors and fixed battery damage (getting a head of myself)
All other connectors disconnected except a2j1 (didnt notice the burnt diodes yet) Got nothing at top dc pins of power supply. bottom panel 1/4 amp sb blew. replaced 1/4 amp fuse checked pins 6-7 of a2j1 got 72v, checked 1-2 and 4-5 incorrectly by not going to ground got about double voltage 24 and 28 respective. Then noticed burnt diodes tried to carefully use jumpers not short them and replaced with 1n4004's band going the correct way. Plugged in the a2j1 ( it was never upside down or 1 pin off) re powered it and the cr4 smoked out, the 1/4 amp slow blow blew again and this time the 3/4amp fast blow at small transformer blew also.
I know i should just buy another power supply but I dont want to ....yet. I dont even know if the cpu works. I might just get a pascal all in one. But this is the important learning hands on part
Where should I look next I assume the small transformer is still ok because I was getting good voltage at a2j1 correct?
Is the power supply shorting somewhere maybe cold solder on back?
Thanks for any input