• Please review our updated Terms and Rules here

Commodore 64 power supply

A

angel_grig

Experienced Member
Joined
Dec 14, 2010
Messages
228
Location
Athens,Greece
I've recently found a breadbin C64.The computer is without a power supply so build one myself with a 9v ac adapter and an AT power supply.I used the schematic from herehttp://www.hardwarebook.info/C64_Power_Supply but I connected the +5V to the pin 4 because checking with the multimeter pins 4 and 5 are connected inside the computer.After powering on, the LED lights but I have no image.My AT power supply outputs 5.35v(as my cheap multimeter indicates).In a SAMS service manual I found that the DC input must be at 5.09v.So,what do you suggest?Should I connect the power to the pin 5?Is 5.35v too high for the c64?Or is it a fault that was already in the computer?
Thanks in advance
 
What you did should have worked. These machines aren't that picky. Also, the Commodore's stock power supply was pretty crummy. Most of them died and got replaced in a similar manner - using surplus power supplies.

Do you get any kind of blip on the screen when you turn on the computer? Also, are you using the correct monitor/cable? A C64 has an RCA plug on it that isn't composite video - it's RF video for a television set. The composite video signals are available at the video DIN plug.

-Ian
 
Thank you all for the replies
@GreatNorthWeb:No,unfortunately I don't have the original power supply,thats why I made one myself
@RetroHacker_:Yes,I'm using the correct cable.I've connected the RCA plug to RF in my tv,and I also tried the composite video with no success,but I will try what you say,to see what happens when powering on.
I also changed the +5v to pin 5 with another power supply at 5.06v without success..
 
I suspect you're probably giving good power to the unit but it's dead for another reason. There are a whole host of issues with Commodore 64's that can cause black screen / no video. Unfortunately the bulk of them require a working unit to 'borrow' parts from.
 
Abbub said:
I suspect you're probably giving good power to the unit but it's dead for another reason. There are a whole host of issues with Commodore 64's that can cause black screen / no video. Unfortunately the bulk of them require a working unit to 'borrow' parts from.
Click to expand...
Thats what I'm thinking too...Anyway I bought for 20 euros (including shipping) a working c64 motherboard from ebay.de,so I have a lot of spares to experiment with :)
 
You must log in or register to reply here.
Back
Top