Schoolboy error with solder paste

[tom66]

Re: Schoolboy error with solder paste

Probably, you could trace it and find out for sure.

Schematics
http://www.tgohome.com/ServiceManual...h=Submit+Query
http://www.tgohome.com/ServiceManual...h=Submit+Query

Looking at the design, it uses transformer isolation to drive the FETs so it's probably only those two FETs plus associated resistors/diodes bad, controller IC may be OK.

[signup]

Re: Schoolboy error with solder paste

Looking at the design, it uses transformer isolation to drive the FETs so it's probably only those two FETs plus associated resistors/diodes bad, controller IC may be OK.

Thanks so much Tom, just one more question the fet that blew was a 9a500v N, Ihave only got 11a 600v N's spare...that will be ok wont it

[tom66]

Re: Schoolboy error with solder paste

Check the Qg is the same or lower... google the specification for both... and if so you should be OK.

[signup]

Re: Schoolboy error with solder paste

Qg on 9n50c is VDS=400v Typical =35
Qg on 11n60C3 = VDD=480v Typical=45

[tom66]

Re: Schoolboy error with solder paste

Not ideal... but close enough that it's unlikely to cause problems. Higher Qg essentially means more heat produced.