[Coco] Coco 1 displaying in B&W

[Rogelio Perea]

On Sat Apr 18 2015, Vincent Tran wrote:

Hi -- Just got back from Radio Shack with a RCA male to RCA female and a
> coax male to RCA Male coupler.  I plugged it up to the Coco 1 and the video
> signal was definitely a lot better - there was no static like before when I
> was using the Nintendo RF adapter.  Unfortunately, I still own a TRS-80
> Black&White Computer.  Everything is still in B&W.  I tried both channels 3
> & 4. Any other suggestions would greatly be appreciated.
>

With the advent of the digital tuner on TVs came the eventual disappearance
of the 'fine tuning' control. The trick for that today is to have the
channel where you are using with the CoCo be flipped up or down then back,
digital tuners fine-tune this way. I have to do this often on the Samsung
LCD flat I have on my workbench CoCo 1 when I power it up and sometimes
when resetting it.

If the channel flipping does not help, as suggested by others try swapping
the MC1372 chip, this is a 14 pin IC that does all the color mixing before
feeding the RF modulator. I recently fixed a CoCo with wavy grainy video
this way. Reseating the chips as suggested is also one of the first things
to try.

-- RP