Re: Dead PET 2001

Re: Dead PET 2001

From: Philip Lord <random6000_at_mac.com>
Date: Fri, 07 Aug 2009 21:25:37 +0900
Message-id: <EDA5C365-1317-4881-8C87-E0C016BB76A1@mac.com>
Hi again,
Sorry it took me so long to get around to measuring the voltages off  
my machine...I hope you are all still here.
So here we go (All voltages are approximates):

Between the two transformer tabs that go to the monitor - 16VAC
Pin1 - 8VAC
Pin2 - 0V
Pin4 - 0V
Pin5 - 8VAC

I also took measurements on the 7805's and as they are tied to pin2,  
there is no voltage read. 0V.
Pin2 and Pin4 both come from the same place off the huge blue  
capacitor, so maybe I can assume this is dead?
Is there anyway to test this capacitor?

Any further advice would be greatly appreciated.

Thanks again
Phil


On Jul 30, 2009, at 11:50 AM, Ethan Dicks wrote:

> On Wed, Jul 29, 2009 at 10:39 PM, William Levak<wlevak@sdf.lonestar.org 
> > wrote:
>> I pulled out my 2001 and took some measurememts.  On connector J8  
>> the center
>> wire is ground. Measuring from the various pins to ground.
>>
>> Pin 1 - 8V
>> pin 2 - 20V
>> pin 4 - 20V
>> pin 5 - 8V
>>
>> Measuring between the two wires on the transformer that go to the  
>> video
>> board - 16V.
>
> That all makes sense - 8V should be enough headroom for a 7805 and
> ISTR there's a 7812 on the monitor analog board, so 16V is plenty hot
> enough to get 12V from a 7812 (+15V happens to be enough).
>
> -ethan
>
>
>       Message was sent through the cbm-hackers mailing list


       Message was sent through the cbm-hackers mailing list
Received on 2009-08-07 14:53:35

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