[Coco] coco 3 help

[Robert Gault]

Josh Harper via Coco wrote:
> hi guys
>
> I have a  dead coco 3  when  turned on  it just  has a blank green screen
>
> I even tried  the cntrl alt reset  to see if  the guys come  up  but no luck  does anyone have any idea of  whats  wrong  and how I can fix it  and  where I can get the parts if needed
>
>
> thanks again guys for all ur  help
>

You must do some basic troubleshooting that will narrow down the problem to a 
specific portion of the Coco circuitry. A good place to start would be section 
IV (Troubleshooting) of the Coco3 service manual. This includes flow diagrams 
for checking the power supply and oscilloscope patterns at various test points.

You can also re-seat any socketed ICs. The contacts can degrade and the friction 
of re-seating the ICs can improve the connections.

If your Coco3 had been working and then quit, what happened just before it died? 
Did you plug/unplug anything with the power on? That can blow a PIA or the CPU. 
Is the an MPI in use? Remove it and see if the Coco will work. Remove anything 
plugged into the Coco, including joysticks, and see if things start working.

RG