Technics SU-G90 with problems

[eugeniog]

hi!

first of all, I'm from Bahía Blanca, Argentina, and we don't have good and capable technical services here, with expertise with this amps, so I'm doing some research to solve this...or at least to find the cause, and them try to find somebody to solve it.

I own a SU-G90 amp (in my family since brand new), and after running some time, and more quickier as higher is the volume level, you hear some "electrical" sound, and then the amplifier goes to a "freeze status", turning off the following, for example: the surround (lowering the rear level), the superbass, the dat/vcr input...

After that happens, you can manually turn on everything again, and works properly for a few more minutes, and then "fails" again...

What do yo think it could be?
is that an overload issue?
is that a high temp issue?
is that a bad solder issue?

when the amp does that, i feel it hot.

I have checked it, and the fan works, and fan's speed is related which amp "charge"...higher volume, higher speed.

I will check the board for bad/cold solder joint.
Maybe I will clean and renew thermal paste.
Maybe I will add a new fan.

Any advice or suggestions are welcomed.

Thanks in advance.

Regards!

 

[eugeniog]

nobody has any advice or suggestions?

 

[rayma]

SMT products often have bad/intermittent solder joints. Using junk speakers, try poking around inside
with an insulated tool (wood, plastic, etc.). See if you can find a connection that cuts in and out when pressed.

 

[eugeniog]

thanks...for my newbie level, taht might be somehow risky...but i will give that a chance