Vic 20 not powering up

Modding and Technical Issues

Moderator: Moderators

Post Reply
Retro Dreams
Vic 20 Newbie
Posts: 6
Joined: Sat Aug 24, 2019 7:37 am
Website: https://sites.google.com/site/retrodreamscommodore/
Location: Alabama

Vic 20 not powering up

Post by Retro Dreams »

Hi guys,

My Vic 20 recently died and I don't know why. I suspect it's the power supply because it has done that before. But when that did happen, I unplugged and left it for a while and it was fine. Yet in this case, its the opposite, I just hope I didn't fry it. The fuse doesn't seem to be blown, however. I reseated all the chips to no avail. There seems to still be voltage on the 6502 processor when checked with a multimeter. Any advice?

Thanks
Computers are like air conditioners. They work fine until you open windows.
User avatar
srowe
Vic 20 Scientist
Posts: 1340
Joined: Mon Jun 16, 2014 3:19 pm

Re: Vic 20 not powering up

Post by srowe »

Ray Carlsen's guide is a good start

http://personalpages.tds.net/~rcarlsen/ ... /vic20.txt
Retro Dreams
Vic 20 Newbie
Posts: 6
Joined: Sat Aug 24, 2019 7:37 am
Website: https://sites.google.com/site/retrodreamscommodore/
Location: Alabama

Re: Vic 20 not powering up

Post by Retro Dreams »

I checked the power supply connecter with a multimeter and there were sparks and I almost was shocked :? I can now safely assume that its sending a crazy amount of voltage to the vic 20. I also forgot to unplug the power supply from the wall :? Does anyone know if it can be repairable or if my vic 20 is fried for good :|
Computers are like air conditioners. They work fine until you open windows.
norm8332
Vic 20 Nerd
Posts: 626
Joined: Sun Nov 13, 2016 11:04 am
Location: USA

Re: Vic 20 not powering up

Post by norm8332 »

Retro Dreams wrote: Sat Aug 24, 2019 2:53 pm I checked the power supply connecter with a multimeter and there were sparks and I almost was shocked :? I can now safely assume that its sending a crazy amount of voltage to the vic 20. I also forgot to unplug the power supply from the wall :? Does anyone know if it can be repairable or if my vic 20 is fried for good :|
If this is the CR version (the one with the round power connector) You may have shorted the 9vac when checking with the meter. This will blow a fuse in the power supply that cannot be replaced if it is a potted supply (filled with epoxy). Almost any VIC-20 can be repaired, but it depends or your electronics repair experience whether it will be successful. I would reference the guide linked to above for starters. If you haven't worked on computers like this before, I would start with youtube to get some pointers.
“In religion and politics people’s beliefs and convictions are in almost every case gotten at second-hand, and without examination... whose opinions about them were not worth a brass farthing.”

-Autobiography of Mark Twain
Retro Dreams
Vic 20 Newbie
Posts: 6
Joined: Sat Aug 24, 2019 7:37 am
Website: https://sites.google.com/site/retrodreamscommodore/
Location: Alabama

Re: Vic 20 not powering up

Post by Retro Dreams »

I opened the power supply and nothing seemed to be wrong when referenced to a photo online of a working one... Still not getting any power. I asked around and my friend suggested that if there's a over-voltage, the vic 20 will automatically stop receiving power from the supply. I'm not sure if this theory is correct, but I hope it is. If anyone can confirm this theory, it would be greatly appreciated.
Computers are like air conditioners. They work fine until you open windows.
Post Reply