Technics SU-V707 Help (Stuck in protection mode)

[PreytorFenix]

Orright let’s start on gathering a sense of what’s goin on in there...

With meter - lead to ground and amplifier on, check for DC voltage from the centre pin of Emitter resistor Z301 (Lch) and then check Z302 (Rch)
View attachment 1694721
If these are near 0V power amp section should be ok and fault will be elsewhere (will go over protect circuits if need be)

I do recommend looking keenly for dry joints too...

So, I am sitting here with the amp opened up. I checked the voltages on the Emitter resistors and neither of them have any voltage coming from the center pins.
Where do you suggest I look next?

 

[PreytorFenix]

Also these mosfet are getting really hot? (white circles)

 

[mbz]

disregard

 

[SVI2004A]

Kia Ora...

Been away for a tad

Let’s look at Q508 on icq control pcb...

Base should be 4.8V
Collector should be 0V
Emitter should be 4.8V

 

[xenon-m]

Hi Guys ! I got this error. Preheating constant, and standby blinking fast. What to do/measure ?!?

 

[coonmanx]

These are really nice amps. I recently got one that was sold "for parts or repair" and had to fix a broken speaker selector switch in order to get it working properly. Your issue seems to be a bit bigger but if you can get it going you won't be sorry. Especially for what you paid for it. They go for a lot more...

 

[SVI2004A]

Check emitter resistors... should be 0v DC

 

[xenon-m]

There I have ~ 4.35V... We can chat directly somehow ? WhatsApp, Viber, Messenger or another ?

 

[SVI2004A]

I have Technics HiFi & Audio on farcebook... - maybe the IM from that would be the best for real time app

 

[xenon-m]

I write there, but someone deleted my post, where I say I want to find You.