Probably a good cleaning and reseating of all the boards is what's needed.
Here is a link to parts and boards of the Marquee. Reseating of the Focus board and HDM is just pulling it out and putting in in a few times to clean the contacts, you dont have to remove any connections to do this. Just pull up and put back in a few times.
http://www.curtpalme.com/Electrohome...e_Layout1.shtm
Location of FCM and HDM.
on the hdm their is a daughter board that also need to be removed and reconected.
HDM Pic
Next on the CLM there are some chips that can be taken out from their
sockets, do one at a time. you will need a IC puller from radio shack to do this.
Location of CLM:
CLM out of Set showing chips.
chip puller pic:
Clean all chips with some contact cleaner or Denatured Alcohol.
I use DeOxit:
Do one chip at a time and remember how it came out so you put it back in the same way.
Athanasios