help for my new Sansui 551

[oldmarantz]

Hi AK members

Perhaps you can help me I picked up today a sweat little Sansui
551L receiver at the first time it runs well but now when it comes to run the light dim and after 1 or 2 minutes no tuner (the amp is ok I try a cd on Aux...)I switch off and switch on later and ok again for 1 or 2 minutes ???

Sure the problem is on the power supply... any idea?

The s/n is strange only 6 characters ---> 509351

Dominic.

 

[RocknRoll]

Just a wild guess but maybe the tuner circuit is going into oscillation after a few minutes? Anyway, it does sound like a capacitor or transistor. Lucky the 551 has metal power transistors? This 441 I have is STK powered with the usuall blown chip syndrome.

 

[oldmarantz]

I followed a red and brown wire under the circuit when it s ok above 14 V and suddenly 1.7 V...sure the tuner will not run with that...I ve got no schems mama mia :

I think like you R&R a transistor or a cap...

 

[Stene]

Schematic

It helps a lot and if you feel it´s worth $9.95 for a complete Service Manual you can find it at http://www.obsinc.us/Dep_VOVS_Literatures.htm