Motorola digital box problem

[WalterB]

My Motorola DCT 2000 digital box developed a problem
at the S-Video output in that the picture has a slow,
noisy band going from the top to the bottom.
The composite video picture on the other hand looks
perfect.
With the box being just out of warranty, my service
provider (Cogeco) tells me to buy a new one since they
don't fix them (I originally paid $344 for it), or to rent one,
which will be replaced for free if it develops any problems.

I am generally handy with working on electronic gear,
but have no experience with those particular units,
so I would appreciate any ideas (leaky cap...?) from
anyone familiar with these digital boxes.
Thanks, Walter.

 

[isw]

My Motorola DCT 2000 digital box developed a problem
at the S-Video output in that the picture has a slow,
noisy band going from the top to the bottom.
The composite video picture on the other hand looks
perfect.
With the box being just out of warranty, my service
provider (Cogeco) tells me to buy a new one since they
don't fix them (I originally paid $344 for it), or to rent one,
which will be replaced for free if it develops any problems.

I am generally handy with working on electronic gear,
but have no experience with those particular units,
so I would appreciate any ideas (leaky cap...?) from
anyone familiar with these digital boxes.
Thanks, Walter.

Sounds like 60 Hz hum. Ground loop?

Isaac

 

[Andy Cuffe]

My Motorola DCT 2000 digital box developed a problem
at the S-Video output in that the picture has a slow,
noisy band going from the top to the bottom.
The composite video picture on the other hand looks
perfect.
With the box being just out of warranty, my service
provider (Cogeco) tells me to buy a new one since they
don't fix them (I originally paid $344 for it), or to rent one,
which will be replaced for free if it develops any problems.

I am generally handy with working on electronic gear,
but have no experience with those particular units,
so I would appreciate any ideas (leaky cap...?) from
anyone familiar with these digital boxes.
Thanks, Walter.

A noise band that's moving slowly is usually a sign of 60Hz
interference. The power supply is the only place inside the box that
this is likely to come from. These boxes run very hot, so check the
power supply board for bad caps (measure their ESR, or look for
bulging caps). The filter cap on the primary side is most likely
source of 60Hz ripple.

Have you eliminated the possibility of a ground loop? Try lifting the
ground pins on any A/V equipment that's connected to the system. Try
a different S-video cable in case there's an open shield.
Andy Cuffe

[email protected]

 

[WalterB]

I used several different S-Video cables but had the same
thing happen.
With the composite video being perfectly clean, I thought
the problem might be closer to the output end, where the
signal is split between the S-Video and Composite terminals,
but I will check for any ground loop, or power supply problems.
Thanks all!