Re: Pet64 DOA

I'm assuming you measured these voltages with the main board connected and
turned on? It certainly does sound like the problem isn't in the PS; time to
get a schematic and start probing... ;-)

Re the PET: Wow, sounds like you've been busy! Bet you're looking forward to
getting it (them) back so you can put it all together.

Obviously you've already made yours and they're easy enough to make, but for
anyone else needing to replace a 6540 character generator or firmware ROM
chip Jim Brain sells those 6540>27xx adapters for $5.00, with provisions for
bank selection with a jumper or switch, e.g. for multiple character sets
like your Japanese PET.

Nicolas' board is obviously more versatile and also adds RAM, but by adding
a few jumpers you can also use one of Jim's adapters to replace all the ROMs
and even also have two selectable firmware/BASIC versions in one chip.

Good luck!

mike


----- Original Message ----- 
From: "Philip Lord" <random6000@mac.com>
To: <cbm-hackers@musoftware.de>
Sent: Thursday, December 09, 2010 12:10 AM
Subject: Re: Pet64 DOA


> 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
>
>
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