Commodore VIC-20 fried?

[smittie]

Hey guys,

I've dug out my old Commodore after a few years. Last time I checked, it was fried. It would not boot up at all. After letting it sit for awhile, however, the LED lights up and it appears to be working, but it will not hook up to my TV set with a cable (DIN plug on one side and red, white and yellow on the other) The power supply has dangerously high voltage (5.8V), so I will be getting a new one, of course. But I need to know if the damage had been done. I thought the problem was with the cable; but after asking on Lemon-64, it's possible that it might be a bigger problem. Even when trying to connect with the RF Modulator showed no avail.

Some people commented on my post and it scared the living schnitzel out of me. I hope to all things holy that my VIC-20 isn't fried.

So now I am asking you guys if you can explain to me how to check the chips on my VIC-20 to see if it's fried or not. Advice is always appreciated!

Thanks!!

https://www.lemon64.com/forum/viewtopic ... 29&start=0
Please check out what I asked on Lemon-64 to give you a better idea.

[Vic20-Ian]

The replies on Lemon are sensible, some of the people on there are on here too like Simon.

If you know the power supply is defective then STOP USING IT!

Borrow a power supply and try that with your Vic20.

The DIN to Red, White Yellow is most likely a Composite Video cable with Audio so you need to select the correct input on your TV to display that.

Do you have another console that connects in this way to composite and not via aerial input?

Test your TV is on composite input with that console, disconnect it. Connect the Vic20 to that composite input and test with a good power supply.

Report back if you get no picture, black picture, garbage on screen, Cyan border and white background but no Read message etc. and you will get more help to diagnose and fix.

[smittie]

Hi,

The input on the TV is AV, I believe that is the correct one. I've got a 1702 monitor that is in storage right now, but I am planning on picking it up.I should try it on there. I will need to order a new power supply off eBay, or from Ray Carlsen. I found a modern one, not an old, unreliable one like I have now on eBay. I am just freaked out because the damage might have already been done and my VIC-20 appears to be fried. I don't know how to verify that is in working order without a good power supply, since I won't have a new one for a while. Is there any way I can check the chips to see if they are in working order? When over voltage occurs, it usually damages the RAM chips, first. For the time being, I have no way of verifying that the RAM is not completely burnt like a sad piece of bacon.
Got any more advice?

-Smittie

[Vic20-Ian]

You could try visual inspection but it will be unlikely to help, they will not likely display a visual fault.

I suggested you borrow a power supply and try that while you wait for a new one.

Without power it will be difficult to diagnose further unless you want to desolder and test components some other way.

DO NOT try and diagnose with the broken power supply, it would likely damage more chips.

[beamrider]

As Ian says, can't do much with a power supply unless you have plenty of specialist equipment, in which case I doubt you'd be asking on here.

I wouldn't worry too much, personally I wouldn't expect a 13% over voltage like that would wreck havoc unless left on for hours. I've seen a video where someone sent 12 volts through it by accidentally bridging traces and mostly got away with it only damaging a 1$ logic chip. In the worst case if you have damaged it, most of the components are replaceable, even the Vic chips can be had for $20 or so if you hunt around.

[smittie]

Hi,

Thanks for the advice. I don't know anyone else who has a Commodore power supply (since it's sort of a unique hobby ) So I think I will just get a reliable power supply from eBay and wait for it to get in. I will immediately get rid of the old power supply since it's no good. I'll get back when I receive the power supply to figure out what to do next. Thanks again!

-Smittie

[Vic20-Ian]

Ask in your local bar?

There are a few million Vic and C64s around.

[joshuadenmark]

Ask in your local bar?

There are a few million Vic and C64s around.

[SmakyTakyOne]

Not in my town... unfortunately... here in Mexico, they are quite rare (the VIC-20s at least).

Ask in your local bar?

There are a few million Vic and C64s around.