Driverboard. Boss audio amp

[S Merlington]

Anyone know the value of these 2 resistors that are missing ?

 

[Perry Babin]

R50 = 220 ohms
R93 = 1.2k

 

[S Merlington]

Do you happen to know the value of R84? I noticed it was burnt also

1 other question also do you know what transistors commonly fail on this board ?

There are 4 outputs in this amp 2 of the outputs get hot fast the outputs that are heating up are the outputs with their 3rd leg connected to the inductor .

 

[Perry Babin]

R84 = 560 ohms.

If the 560 ohm resistor burned, it's not a common failure. You'll have to check every component.

Those outputs are the high-side outputs. Their drivers are the four transistors nearest to the op-amp.

 

[S Merlington]

Found the problem ..

Someone tried to repair this before ..

They had MPSA42'S in Q42,43,44 they should be MPSA92'S

 

[MarioRestucci]

Hi, anyone have schematic for this driver board?
i've tried to reverse enginering, but i've failed.
my email joetvanelliclub@gmail.com
thanks to all

 

[jacampb2]

Hi, anyone have schematic for this driver board?
i've tried to reverse enginering, but i've failed.
my email joetvanelliclub@gmail.com
thanks to all

Generic Asian Clone driver board RE and Clone