[TenTec] Paragon is it dead?

[Louis Ciotti]

Thanks Mike.

I scoped out those two ICs (U10 and U111), and they appear to be 
functioning fine, at least the signals coming out of them look like TTL 
logic.



Mike Bryce wrote:
> FYI….
>
> The last Paragon I worked on had about the same issues. I traced the problem to two common CD4000 series ICs in the rear left corner of the mother board. It’s been so long that I don’t remember the number of the chips. They are common off the shelf parts.
>
> That cured the goofy logic board problem.
>
> MIke, WB8VGE
>
>
> Mike Bryce
> prosolar at sssnet.com
>
>
>
>> On Sep 14, 2016, at 12:42 PM, Louis Ciotti<lciotti1 at gmail.com>  wrote:
>>
>> Fresh battery is in place.
>>
>> I really thing it is either a dead CPU or the EEPROM got scrambled.  I
>> found a source for a low cost CPU so I ordered it.
>>
>> When looking at the signals with the O'scope, the IRQ line does not look
>> right:
>>
>> https://goo.gl/photos/6ohJcT8Lu4qrSsVp9
>>
>> All the other logic line look nice with out the finky ripple on the lines.
>> If I remove the CPU this line goes to nice smooth a logic high, which is
>> what ll the digital line with a logic high on it look like.
>>
>> If I swap the CPU and that does not cure it, I am going to say the EEPROM
>> is dead.
>>
>> I wonder if TenTec would have the source code for the 6805 assembly code,
>> or the EPROM image stored somehwere and I can re-burn since it looks like I
>> can still get the eprom as well, I just would need to get a burner.
>>
>>
>
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