Cannot power up PJB Briefcase amp.

[Tony Ellis]

Power is getting to 12V terminals, but power switch indicator on front panel will not light. All fuses checked Ok

Any suggestions?

[tauzero]

Fuses checked with a meter? Does it have a power switch on the amp, and if so, can you check if power is getting through the switch, and that power is getting through the power connector OK?

[Bigguy2017]

I do not know the specifics of this amp but general principles apply...

 

Is this the same PJB model as attached .pdf schematic shows... ?

 

First check 15VDC and 12VDC supply rails are AOK - they both have internal fuses (as does the other 12VDC battery supply).

If you can unplug the power supply from the main board (plugin connectors?) will it power on now? Are all voltages present?

 

If all DC volts are AOK then there's a problem on the main board;

Look for burnt or discoloured components, leaking or swollen capacitors, bad solder joints or damaged PCB tracks. Have a sniff- any burnt electrics smell?

 

 

pjb_phil_jones_bass_briefcase_sch.pdf

Edited October 12, 2024 by Bigguy2017