Yamaha RX-A1020 protect

[hanasaku]

HI, i wonder i someone can guide me with my yamaha receiver, i test almost everything that i found on the net, im run out of option, i have in all the channel -7v and just the right front -5.2v, i check and i have randomly 6 and 8 v from the signal AMP_OLV, all the power supply signal are ok, sometines i have goog voltages on the +B and -B but now a have 70v and -55v.

Thanks for the help

[hanasaku]

Re: Yamaha RX-A1020 protect

anyone can guide me?

can be a floating ground i suspect, or a bad capacitor.

thanks in advance.

[hanasaku]

Re: Yamaha RX-A1020 protect

i found something on the right channel, the resistor R1111 3 point 22ohm x2 just one side was ok, and the diode D1028 was open/Bad.

i will check changing this .

[petehall347]

Re: Yamaha RX-A1020 protect

check the output transistors .
am guessing the resistors are 2x 0.22 ohms

[hanasaku]

Re: Yamaha RX-A1020 protect

check the output transistors .
am guessing the resistors are 2x 0.22 ohms

yes. one of the 0.22 ohms resistor fail, i already change and the diode but burn the transistors on the right channel .

[hanasaku]

Re: Yamaha RX-A1020 protect

I suspect the problem is in the -LB signal because R1287 and Q1098 are extremely hot but they work, also the signal shorting the double resistor is the positive transistor Q1048P which is connected to the -LB_R

[hanasaku]

Re: Yamaha RX-A1020 protect

This 2 components are hot even if i isolate the amp side , Its that normal?