Newer Model Vic-20: Screen Output Problem

Goro123 · Post by **Goro123** » Wed Apr 08, 2009 2:49 am

Okay, so I have a thread about the older Vic I own, and I think I've narrowed down the problem there. RAM chips and 555 chip to be replaced.

Now I have this newer model Vic that is giving me problems. I remember playing this back when I was kid and one day it went all funny on me. To this day, it continues to act up on screen whenever I turn it on. To make life easier, I have a video:

http://www.youtube.com/watch?v=CAfJXvt_etM

Any ideas?

6502dude · Post by **6502dude** » Wed Apr 08, 2009 7:16 am

Since you have two Vic-20s, try swapping the 6560 chip between units and see if problems move between computers.

Goro123 · Post by **Goro123** » Wed Apr 08, 2009 12:31 pm

Tried that already. Same problem. Maybe I need to strengthen the signal going into the TV? I just find it weird how one can get picture, the other cannot, with the exact same setup.

a4000bear · Post by **a4000bear** » Thu Apr 09, 2009 9:30 pm

I have never used an RF modulator on a VIC, but that video looks like you have severe AC hum in the signal. How is the modulator powered?

Have you tried the video output without the modulator?

Goro123 · Post by **Goro123** » Fri Apr 10, 2009 2:29 pm

I'm using the modulator attached to a coaxial cable, run into the TV. I have one of those connectors that attach into the RF Modulator which changes the connection so a cable can be used.

I also tried the connection with another modulator, same output.

shem · Post by **shem** » Fri Apr 10, 2009 6:05 pm

maybe something is dragging the 5 volt line do any I's get hot especially ram and roms? could you measure the voltage with the vic20 turned on ?