[time-freq] REF input problems Reflock 2

[Luis Cupido]

Very fine.

Take a look on my web pages and look for the
configuration you want.
It is indeed advisable to load the 'pof' file
again before final conclusions.

http://www.qsl.net/ct1dmk/reflock.html

lc
ct1dmk.



On 2/29/2012 1:51 PM, Merv Thomas wrote:
> Hi Luis,
>
> Thanks for the prompt response and information.
>
> There is definitely no short from pin 89 GCLK2 to any adjacent pin so
> the suspect seems to be the CPLD itself.
>
> I wonder in the event that the firmware that was downloaded into this
> CPLD had a glitch in it that pin 89 might have been configured as an
> output to ground instead of an input?
>
> For this reason I have separately emailed you for other files to help
> possibly trace a software fault. I have the assistance of a highly
> qualified electronics engineer/programmer who is willing to spend time
> on this at no cost to me(a fellow radio amateur(VK6IC).
>
> Any help you or anybody else can provide will be appreciated.
>
> Regards,
>
> Merv VK6BMT
> ----- Original Message ----- From: <time-freq-request at tapr.org>
> To: <time-freq at tapr.org>
> Sent: Wednesday, February 29, 2012 8:00 PM
> Subject: time-freq Digest, Vol 37, Issue 1
>
>
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>> Today's Topics:
>>
>> 1. Reflock 2 (Merv Thomas)
>> 2. Re: Reflock 2 (Luis Cupido)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Wed, 29 Feb 2012 17:49:29 +0800
>> From: "Merv Thomas" <vk6bmt at iinet.net.au>
>> Subject: [time-freq] Reflock 2
>> To: <time-freq at tapr.org>
>> Message-ID: <CE72EC6C488F43828B1583A447124C25 at merv>
>> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>> reply-type=original
>>
>> Hi - I have a populated board that is not working. The output of the
>> BFT92
>> transistor on the REF input chain - that is the input to CPLD pin 89
>> GCLK2
>> is being pulled down to about 180 mv. If I cut the trace on the board to
>> this pin then the output from the BF92 goes up to 2.6v Seems like an
>> internal short in the CPLD chip.
>>
>> The input to pin 91 GCLK3 has 2.6v on it from the BF92 in the VCXO input
>> chain which seems correct.
>>
>> Does this show that the CPLD is not serviceable please?
>>
>> I know most of the forum comments on this subject go back some years
>> so I am
>> hoping that maybe Luis Cupido or someone can answer my question!!!
>>
>> Regards,Merv VK6BMT
>>
>>
>>
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Wed, 29 Feb 2012 11:08:10 +0000
>> From: Luis Cupido <cupido at mail.ua.pt>
>> Subject: Re: [time-freq] Reflock 2
>> To: TAPR time and frequency projects <time-freq at tapr.org>
>> Message-ID: <4F4E071A.3020904 at mail.ua.pt>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> Hi Merv,
>>
>> You must be sure that you don't have any short circuit on the CPLD
>> pins somewhere, the 180mV may suggest also a short circuit to a pin
>> being used as output.
>> (I did not check how I have the unused pins, but they are likely to be
>> configured as outputs driving ground, so check a short to a unused pin ).
>>
>> Once you have discarded this short circuit possibility
>> the CPLD itself will be the next part to suspect.
>>
>> Luis Cupido.
>> ct1dmk.
>>
>>
>> On 2/29/2012 9:49 AM, Merv Thomas wrote:
>>> Hi - I have a populated board that is not working. The output of the
>>> BFT92 transistor on the REF input chain - that is the input to CPLD pin
>>> 89 GCLK2 is being pulled down to about 180 mv. If I cut the trace on the
>>> board to this pin then the output from the BF92 goes up to 2.6v Seems
>>> like an internal short in the CPLD chip.
>>>
>>> The input to pin 91 GCLK3 has 2.6v on it from the BF92 in the VCXO input
>>> chain which seems correct.
>>>
>>> Does this show that the CPLD is not serviceable please?
>>>
>>> I know most of the forum comments on this subject go back some years so
>>> I am hoping that maybe Luis Cupido or someone can answer my question!!!
>>>
>>> Regards,Merv VK6BMT
>>>
>>> _______________________________________________
>>> time-freq mailing list
>>> time-freq at tapr.org
>>> https://www.tapr.org/cgi-bin/mailman/listinfo/time-freq
>>>
>>
>>
>>
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