[Coco] Screen roll on model 1

[Richard Goedeken]

It's a ground loop. Look at everything that you have in your A/V setup:

1. The TV
2. Everything that's connected to the TV
3. If you have a receiver which is sending a signal to the TV, everything
connected to the receiver.

Basically all of the components which are in this whole network of stuff. Look
at the power cables for each component. Do any of them have 3-prong power
cables? If so, disconnect these components. Once you have removed all of the
extra ground points, your rolling bar / ground loop will go away. If you have
an antenna feed for a cable subscription which attaches to your TV (or a
decoder box which is connected to your TV), then this is your ground point,
because the cable feed is grounded at the demarcation point on the side of
your house where it comes inside. If any of your other devices are also
grounded (ie, through the 3rd prong on a power cord), then it forms a giant
loop which picks up 60hz hum, which looks like a rolling line on your TV.

Richard

On 09/24/2018 05:27 PM, rietveld rietveld wrote:
> Hi. Not coco but trs80 anyway
> 
> I am getting a constant vertical screen roll on my model1's original
> monitor. Thinking it was a problem with the monitor I just built one of
> Mav's composite cables. I am still getting the same vertical roll on an old
> Tandy vm2 as well as a newer flatscreen monitor using the comp in
> 
> It seems that the model 1 is the problem.    What should I be looking at?
> 
> Sent from my BlackBerry
>