C64 not turning on.

[The Mr. Video]

Hi, recently I replaced the power port on my C64 because the old one was faulty, but afterwards turning the C64 on gave me a black screen. I tried bridging the power connections because I tested for continuity with a multi meter and figured out that some of the pins can't send power to the board, but I still got a black screen. Now when I try to turn on the C64, I doesn't even power on. I know it's not the PSU because I've tried two different PSUs and both net the same result and neither the Datasette nor the 1541 react at all to the C64 turning on.

[rpiguy9907]

The fuse is good?

[The Mr. Video]

The fuse is good?

Checked the fuse and it was good, I've even tried different fuses and nothing's changed.

[rpiguy9907]

Does pin 2 on the user port get +5 volts as expected? That is an easy way to see if power is getting through your board. The 5V line supplied power to most of the computer the higher voltages are for the SID, which the machine can boot without I think. If there is no voltage then you have a short somewhere.

 

If you are getting +5v power on the user port, do you have any ROM carts you can test with? Even a game cart?

 

Common cause of black screen is the Kernal ROM. If it boots with a game cartridge plugged in, but does not boot without a cartridge in, then it points to a dead Kernal.

 

Once you've gone through the above it sort of becomes a deduction game. Feeling around if any chips get hot, etc.

 

You can try swapping out PLAs then CIAs if you have spares, etc.

[The Mr. Video]

So I tested pin 2 on the user port, and it doesn't seem to be getting power.