Re: Pet64 DOA

The supply voltages to the ICs are all correct?

Reset line is being released?


----- Original Message ----- 
From: "Philip Lord" <random6000@mac.com>
To: <cbm-hackers@musoftware.de>
Sent: Thursday, December 09, 2010 3:23 AM
Subject: Re: Pet64 DOA


> Well, it seems like the power might be ok after all, so I broke out my  
> logic probe...it's a cheap one but has helped me fix many simple  
> issues over the years.
> 
> The first think I noticed after probing around is that I'm not getting  
> any pulsing (or at least that what the probe indicates), lines are  
> either high, or low, or nothing, but there doesn't seem to be any  
> pulsing at all!
> 
> So I guess I should look at the timing circuit or Xtal? Anywhere else?  
> Not sure how to test is a Xtal is working as I don't think my probe  
> can do that.
> 
> Cheers
> 
> Phil
> 
> 
> 
> On Dec 9, 2010, at 2:10 PM, Philip Lord wrote:
> 
>> Great...so then maybe my power voltages are all good? Should I find  
>> some test point on the C64 motherboard and get some voltages there?  
>> Any idea what I should check next?
>>
>> Re-PET board. Ethan has been working very hard, and he believes he  
>> has fixed both boards now (but can not test loading as his C2N data  
>> cassette deck is in need of a new drive belt). Last I heard  
>> everything is almost packed up and ready to ship. It would be great  
>> to get the boards back before years end, as I have been building a  
>> number of add-ons in anticipation for their arrival and I'm excited  
>> to try everything out.
>> I have built one of Nicolas Welte's Ram/Rom boards which will  
>> hopefully take my ram to 32k and allow me to use various basics (V1  
>> through V4) and not have to worry about failing RAM in the future. I  
>> have also built a number of adaptor boards to replace the video ram  
>> and character ROM. Finally I got myself a C2N232 as I don't know how  
>> reliable the original cassette drive is. I'm hoping to 'fail proof'  
>> this machine for at least another 30 years ;-)
>>
>>
>>
>>
>> On Dec 9, 2010, at 1:44 PM, MikeS wrote:
>>
>>> 5V DC and 9V AC - sounds OK.
>>>
>>> Did you finally get your PET boards back and working?
>>>
>>> m
>>>
>>> ----- Original Message ----- From: "Philip Lord" <random6000@mac.com>
>>> To: <cbm-hackers@musoftware.de>
>>> Sent: Wednesday, December 08, 2010 10:41 PM
>>> Subject: Re: Pet64 DOA
>>>
>>>
>>>> 8.91 vac
>>>> On Dec 9, 2010, at 12:31 PM, MikeS wrote:
>>>>> Hi Philip!
>>>>>
>>>>> What AC voltage do you get between the two white wires?
>>>>>
>>>>> mike
>>>>>
>>>>> ----- Original Message ----- From: "Philip Lord" <random6000@mac.com 
>>>>> >
>>>>> To: <cbm-hackers@musoftware.de>
>>>>> Sent: Wednesday, December 08, 2010 10:07 PM
>>>>> Subject: Re: Pet64 DOA
>>>>>
>>>>>
>>>>>> Sorry maybe I should have tested the some lines using AC not DC.
>>>>>> So here again is what I believe I have (suing the black line as  
>>>>>> GND):
>>>>>> White: - 5.8 vac
>>>>>> (KEY)
>>>>>> White - 0.5 vac
>>>>>> Black (I'm guessing this is ground)
>>>>>> Red - 4.98 vdc
>>>>>> Of course I could just be confused as I've never owned a C64  
>>>>>> before.
>>>>>> Looking at schematics seems maybe the two white lines could/ 
>>>>>> should  be  9vac, and maybe the red line should be 5 vdc???
>>>>>> Phil
>>>>>> On Dec 9, 2010, at 11:16 AM, 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
>>>>>
>>>>>    Message was sent through the cbm-hackers mailing list
>>>>     Message was sent through the cbm-hackers mailing list
>>>
>>>     Message was sent through the cbm-hackers mailing list
>>
>>
>>      Message was sent through the cbm-hackers mailing list
> 
> 
>       Message was sent through the cbm-hackers mailing list

       Message was sent through the cbm-hackers mailing list