Re: Pet64 DOA

From: Philip Lord <>
Date: Thu, 09 Dec 2010 12:08:33 +0900
Message-id: <>
Oh...Hi Pete, you just read my mind.
I was just looking at some schematics and it seems that the C64 needs  
5vdc and I decided to recheck using AC setting on my  

White: - 5.8 vac
White - 0.5 vac
Black (I'm guessing this is ground)
Red - 4.98 vdc

I was also wondering if this type of power supply needed some draw to  
measure the voltages correctly (I know the Apple II does, but this  
transformer arrangement looks much simpler than the II's, so maybe not.


On Dec 9, 2010, at 11:45 AM, Pete Rittwage wrote:

> On 12/8/2010 9:15 PM, Philip Lord wrote:
>> I just got myself a PET64 from Yahoo Auction Japan. Quite a rare  
>> machine I hear, so I'm not sure how one ended up in Japan. I got if  
>> for a decent price as I don't think the Japanese knew exactly what  
>> it was.
>> Anyway, It arrived the other day, after a quick internal  
>> inspection, I powered it on. I can hear the transformer buzzing(!),  
>> but no action at all on the screen at all, and it doesn't seem like  
>> the chips are getting warm at all Maybe need to leave it on a  
>> little longer to make sure, but I didn't want to do that incase bad  
>> voltages kill anything more).
>> There are 4 wires leading from the small PCB which is attached to  
>> the transformer to the C64 motherboard, and I have measured the  
>> voltage from the black wire (GND?) to the 3 others. Here are the  
>> reading i get:
>> White: - 100mv
>> (KEY)
>> White - 100mv
>> Black (I'm guessing this is ground)
>> Red - 4.98v
>> That's as far as I have gotten. Next I will remove the motherboard  
>> and see where exactly these 4 wires go.
>> Anyway, I was just wondering if anyone had any insights or thoughts.
>> Cheers
>> Phil
>>      Message was sent through the cbm-hackers mailing list
> I believe your white wires should be 9VAC, so I would remeasure in  
> case you used a meter on DC setting.
> -
> Pete Rittwage
> C64 Preservation Project
>      Message was sent through the cbm-hackers mailing list

       Message was sent through the cbm-hackers mailing list
Received on 2010-12-09 04:00:09

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