800XL dark, glitchy video output?

[spacecadet]

I'm trying to get my 800XL up and running after about 20 years sitting in a closet. I've already replaced the power supply after my old one started doing this, and the new one (the good kind from Best) seems to work fine.

 

However, first, my video output through composite (all I can currently display) is quite dark. I've had to turn up the brightness on my monitor vs. the level that's comfortable for my C64 and Tandy 1000 on the same monitor. (The C64 is also going through composite, with the same cable.) It's annoying having to constantly adjust this whenever I switch computers.

 

Second, every couple of minutes the video will just kind of glitch out for like half a second, then go back to normal just as quick.

 

I suspect *something* is going bad internally, but no idea what. I did a search and couldn't find another post about these specific symptoms together.

 

I also wonder if my earlier power supply problems fried something, although generally the computer seems to work fine, and I was able to play a bunch of games last night. It just has these couple video issues. I do wonder if the relatively dark output might be just the way it is, but I worry about it because of the other issues I've had.

 

Thanks for any help.

 

[+Roydea6]

There is a small hole on the bottom of the 800XL that allows a small tuning screwdriver to adjust the color pot. Not sure it your dark screen is related to this or not.. But if you try it might lighten the screen some.

[+Stephen]

I'm trying to get my 800XL up and running after about 20 years sitting in a closet. I've already replaced the power supply after my old one started doing this, and the new one (the good kind from Best) seems to work fine.

 

However, first, my video output through composite (all I can currently display) is quite dark. I've had to turn up the brightness on my monitor vs. the level that's comfortable for my C64 and Tandy 1000 on the same monitor. (The C64 is also going through composite, with the same cable.) It's annoying having to constantly adjust this whenever I switch computers.

 

Second, every couple of minutes the video will just kind of glitch out for like half a second, then go back to normal just as quick.

 

I suspect *something* is going bad internally, but no idea what. I did a search and couldn't find another post about these specific symptoms together.

 

I also wonder if my earlier power supply problems fried something, although generally the computer seems to work fine, and I was able to play a bunch of games last night. It just has these couple video issues. I do wonder if the relatively dark output might be just the way it is, but I worry about it because of the other issues I've had.

 

Thanks for any help.

 

What kind of monitor are you using? I have had similar behaviour on LCD monitors, where it would loose the colour synch every 30 seconds or so due to the non-standard Atari signal.

[spacecadet]

What kind of monitor are you using? I have had similar behaviour on LCD monitors, where it would loose the colour synch every 30 seconds or so due to the non-standard Atari signal.

 

Magnavox version of the Commodore 1084. I don't think it's that, unless the 800XL somehow has non-standard composite output?

[+Stephen]

 

Magnavox version of the Commodore 1084. I don't think it's that, unless the 800XL somehow has non-standard composite output?

No - it should work perfectly fine with that style monitor.