Task TK-940TX-DF Blowing fuse

[Dan81]

Re: Task TK-940TX-DF Blowing fuse

Yeah, seems it has no APFC (please tell me it wasn't supposed to have APFC lol)

As for the 384P, yes, you do have to remove it and test for shorts.

[socketa]

Re: Task TK-940TX-DF Blowing fuse

Only this next to the fan - it's not really "huge" - so no APFC?


How do i test the TL384P? - do i have to remove it and test for shorts?

[Dan81]

Re: Task TK-940TX-DF Blowing fuse

Thanks,
Took off the Bridge rectifier - TOK
Then a K2746 - No shorts
Then had to remove the heat sink and there was a shorted K2746 field transistor on the other side of it. (managed to lift a trace - note to self: remember to dont push on soldered components)
Could the bad secondary caps (or is is the Fuhjyyu primarys?) have caused the transisor to short?
Yep, the two primary caps are LP 820uf 200V, which measure 740uf and 750uf, and about 0.05 and 0.03 ohms ESR.

Did the PSU have a separate board with a HUGE coil attached to it on the primary? If it's there, then you may have a dead APFC, and could very well be the reason for the failed transistor. Fuhjyyu primaries + APFC = no bueno. If my memory serves me right, I would also check the TL384P on the primary, as on mine that went bad too.

[socketa]

Re: Task TK-940TX-DF Blowing fuse

Thanks,
Took off the Bridge rectifier - TOK
Then a K2746 - No shorts
Then had to remove the heat sink and there was a shorted K2746 field transistor on the other side of it. (managed to lift a trace - note to self: remember to dont push on soldered components)
Could the bad secondary caps (or is is the Fuhjyyu primarys?) have caused the transisor to short?
Yep, the two primary caps are LP 820uf 200V, which measure 740uf and 750uf, and about 0.05 and 0.03 ohms ESR.

[Dan81]

Re: Task TK-940TX-DF Blowing fuse

Checked the primary transistors and the bridge rectifier?

Also, replace the primary caps ASAP. This is a Andyson unit btw, and I know for a fact that they use Fuhjyyu caps (branded "LP" which is actually the series) which are asking for trouble in Andyson units. (I have one that was killed by them)

[socketa]

I saved this PSU from a PC that someone threw out
The teapo output caps are bulged
It's got a TL384P chip on the primary side.
Plugged it in, turned it on, it worked for a few minutes, and then the 10A fuse blew (leaving the surrounding area blackened).
Then i put fuse holder in, and a new fuse, and it blew again the instant that i switched the power on.
There is no short from live to earth when it is unpowered, so what could be causing the fuse to blow?
By the looks of it, it's probably not a very good PSU but i wouldn't mind trying to get it working because it has longer power connector wires than my other ones.