Re: Harman Kardon HK3490/230 blows power-transistor

Thanks for the suggestions and schematics. I've never had any issues disconnecting devices in this way on other receivers/amps, short circuiting an input should not be a problem (if connected to ground that is). This receiver cannot handle it, that has been proven. I will create a buffer to prevent further blowouts. Thanks again.

I have a Harman Kardon receiver (HK3490/230) which has blown its end power-transistor (2SD2401 - physical damage). Both fuses are toast also.

This has happend before when a portable device had been connected and disconnected. I replaced the power-amp and its companion 2SB1570 and could not find anything else wrong - replaced the fuses and it was running again, until a few days ago. My son connected his tabled to a line-input and played some music. After disconnecting it, the receiver produced some smoke and died - hence fried 2SD2401 (cracked and hole in it).

Did...

Re: Samsung LE26B450C4W Dead PSU

Just to let u know: The PSU is alive again - a new fuse, new controller (ICE3BR0665J) and new zener diode 1N4740A. PC801 is fine (no replacement done).
Total cost: € 2,54

Re: Samsung LE26B450C4W Dead PSU

Thanks very much budm - also for the schematics! This will help me fix this psu

Re: Samsung LE26B450C4W Dead PSU

Hi windy, I have the same defect on this PSU. I have ordered a replacement IC, but I cannot read the numbers on the ZM801 diode.

The symbol states a zener-diode, and it starts with 1N and ends on 47A, but in between something like 4? (stil 10 combo's)

Can you remember or look up the correct type for that diode?