Can you post some pictures ?
The 5 pin DIN has composite video and audio lines, if you do not have the original cable you can use this diagram to make your own. Your TV must have a composite Video input.
The Vic20 5 pin DIN out is same as the c64 5 pin DIN out http://c64os.com/buyersguide/multimedia_breakout
The original PSU was 9VAC 2Amp and if your VIC has that label "9V AC" then that is what you want to use, the rectifiers and DC regulation is on board. Do not use a DC PSU unless you know what you are doing and it need to supply at least 2 amps.
Is late, am tired and best my memory can give ATM.

this is better picture http://junkskool.net/images/photos/wifi/20210 … 49_IMG_0578.JPG

I start to think the vic20 really need it's 9v AC line, unlike the amiga it seem the vic20/c64 need both voltages all the time. Horun I have the "cost reduced" version of the board so the PSU need to provide 5v DC and 9v AC. I read you can easily edit a 12v DC into a 9V AC by bypassing the diodes loop. I got just one of those 12v DC wall wart so I'm a bit reluctant to open it since it's sealed down and not screwed and it will break the case to open it. Someone suggest I could use a DC adaptor instead of an AC but while I don't see how the vic20 need the AC phase I read the voltage are not calculated the same and I could very well destroy some parts.

About the video I see I need only to use pin 5 called Video High. So now I guess I should not try to hurry thing and search for a way to feed that 9v AC line.

I think the accessory parts use the AC (thru on board rectifiers + regulation) where the main logic uses the DC 5 volt regulated directly on those models. Early versions used just the 9 to 11v AC and regulated both parts onboard iirc
oh yeah Wiki has it: http://sleepingelephant.com/denial/wiki/index … =Power_Supplies
So you need 5V DC @ 1.5A (1500 mA) plus 9v AC @ 2A. The 5 Volt is most important and it should work IF your 5v supply can give out 1500mA or more.

Thanks for that Horun, I did not had found in my previous research that sleepingelephant.com wiki link you gave me. But anyway I think I will declare it game-over for that computer. I found information that goes the same way as we think that the logic is 5v and some mechanical devices where on the 9v ac here. So I tested with 5v DC 1.5a and 9&12V DC 5a but it changed nothing.

I did put the vic20 on a TV but could only seen some weird gradient artefact, using a oscilloscope show nothing of what would look like a composite video signal.

Oh well, people rarely put working computer in the trash and I guess I was not lucky this time. Your support was much appreciated Horun.