Cracked solder joints near the relay? Martin

Hi, Also check the transistors in the output stages, especially drivers and pre drivers. They can be intermittent.

Thanks for your feedbacks I will look at it accordingly, since then the situation changed and now when switching on a big bump occurs immediately and the unit is working I rememeber the previous 4400 I repaired there was a 2 to 3 seconds delay before the unit started, this one no delay, can we adjust this and how? Many thanks Alain

No you can’t. The thump is normal. Mine has done that every day for almost ten years. Many amps have a speaker switching relay to avoid it. To reduce it, you may try new power supply capacitors, but it will still be there. If the problem magically disappeared it may come back, so beware. Jacques

OK thank you Jacques

Hello, I have here a new behavior of my 4400 unit I dont know how to correct. When switching from an FM selection to Tape 1 or 2, or Phono, the display related to FM stereo lamp and tuning indicator remains lit for sometimes up to 10 seconds and then disappear. It does not affect the sound and functioning . The 15V still there during this time, how to corect this ? Is TR1 involved and  how?   Alain  

Hello After checking some parts ofthe 4400, it appears that one end of the P6 pot for adjusting the channel number 6 is left open when it should be grounded. To be corrected of course. Hopefully can be done without difficulties. Cheers   Alain

actually it was one leg of the P6 switch to be grounded, stangely it was not. If left open the front end is missing the voltage for the varicaps and it is free running