Kenwood KA-1010 burn out

[caveman]

Hi guys, if anybody could help me with this, my mate's got a 1010 that has just lost all bass response, can anybody suggest components to check? Can't find the schematic for free anywhere

now

[Jazz P Bass]

Kenwood Ka 1010

Lost all bass response.
Both channels?
If so , check the power supply main + & - Vdc .
The Vdc should hold steady, with very little Vac ripple.
Check to make sure it is not a speaker problem.

[caveman]

Both channels yes, can't see it being a speaker problem, maybe a coupling cap or gain resistor is shot. I'll check the voltage like you say, any steps to take after that?