[Coco] need help repairing a coco 2

[Rogelio Perea]

On Wed Oct 15 2014, didier derny wrote:

I have a coco 2 with no video on tv output.
>

An obvious first check should be the voltage from the power supply. Once
that is checked, on any CoCo with those symptoms I would go first after the
6809 CPU. All CoCos I have repaired get at new 6809 and a new socket mount
for it on the CoCo board - that way one can easily replace a faulty CPU.

Even if it is not the CPU, the CoCo will benefit of a new socketed 6809 -
with the assurance that the CPU is not the cause then you can focus the
troubleshooting on other areas: RAM first and then the support chips SAM -
memory management, VDG - video display, PIAs I/O.

-- RP