vic 20 video problem

[bradhig1]

I just got penultimate 2 cart today and when I first turned on my vic 20 after connecting it through rf to my tv the picture was fine. Now the TV can't pick up the signal and when I do see it the picture is wavy and shaky like crazy.  I tried both ch 3 and 4 same thing. I have an av cable with a white plug and a red plug I tried running through my av to hdmi converter and didn't get a picture.  How do I fix this?

[bradhig1]

now it is just a blank black screen.  Could the vic chip be bad?

[Grimm1966]

Do you have a way of displaying composite? You can hook up the same composite cable that is used for a C64 and use it on the VIC.  I go through a RetroTink for mine.  At least you will be able to tell if it's an issue with the VIC chip or not.  Sometimes the AV to HTMI converters are a bit flaky.

[bradhig1]

I couldn't get anything through my a/v to hdmi converter before I used the rf.  COmposite cable has red and white cables while hdmi converter has red ,white , and yellow coonections.  I don't know if white or yellow is video.

[Grimm1966]

Usually a composite cable has three RCA jacks on the monitor end (Yellow - composite, Red/White would be audio)  Mostly for these old computers, as they only had mono sound, the Red and White connectors were wired together. If you have a cable that someone cobbled together, than you will need to check which one is composite and which one is audio.  You can do a continuity test to see which pin goes to which RCA jack (Pin 5 is composite).  

 

https://allpinouts.org/pinouts/connectors/computer_multimedia/commodore-vic20-video/

 

Once you know which RCA jack the composite signal is on, that one will plug into the Yellow connector on your converter.  The other will be audio most likely and plugin to either the red or white connector (shouldn't matter which one).

[bradhig1]

I tried both jacks in the yellow plug and still no video.  On the RF connector I got a black screen.

[Grimm1966]

You have three issues here, it could be a problem with the AV converter, a problem with the cable, or a problem with the VIC.  You need to find methods to either confirm or eliminate these problems.  For the AV converter, if you have another computer you could connect it to, then you can test it to make sure it's working or not.  If you have done the continuity test on the cable with a multimeter and determined which of the pins on the DIN connector goes to which RCA jack, that will determine if the cable is good or not.  You will not be able to really test the VIC until you know that all of your equipment is working correctly. 

 

If you watch any of the YouTubers that fix these old computers (Adrian's Digital Basement, 8-Bit-Guy, etc.) they will always test their equipment before trying to fix a broken system.  Because if you don't know if your equipment is working, you will not be able to fix the broken system.  You can go down a lot of rabbit holes thinking that the issue is the old computer when the problem is with the other equipment you are using.

[bradhig1]

I plugged both av cables into my c64 and not picture from either.  I have a new rf converter cable for my vic20 coming tomorrow and a new av cable later this week.

[eightbit]

Maybe you should show us some pictures of all of this so that we can get a better idea of what you are doing.

[carlsson]

Most likely, a random cable wired with one 5-pin DIN to two RCA plugs has the outer pins 1, 3 and middle pin 2 (GND). That works for Sega Genesis 1 but not for Commodore. You might get sound on one of the plugs but never video.

 

However if your VIC-20 used to work fine until you plugged in the cartridge, probably something broke inside that a different cable can't fix.

[bradhig1]

Got a new rf cable today.  It works but there is an annoying buzz on the audio.

[carlsson]

Do you solder? Is either of the AV cables possible to take apart the DIN end? If the answer is yes on both questions, you might want to hack one of those into a proper composite video cable that will work on both the VIC and C64. From what I can tell, you might only have to desolder one wire and move it to a different pin.

[eightbit]

Just get a proper A/V cable. If you need one I have one for sale that is proper for the Vic-20 and is wired for dual audio output (dual mono).

 

You can have it for $20 shipped. PM if you want it.

[bradhig1]

the rf box can be opened with a screwdriver. I will check that out.

 

[bradhig1]

Just got a new a/v cable and the picture is clear and free of buzz.