[Premium-Rx] RA1792 Problems. Help Please!

[David Schofield]

Hi All,

As most of you  may have noticed I don't know my Left from my Right :-) .
Stuart. The processor PCB is on the RIGHT hand side at the top not the left.
There are no PCB'S on the left hand side.

Thanks,
Dave.S.



David Schofield wrote:
> Hi Stuart,
>
> The short answer to your question is YES. There are very well known 
> faults on the RA1792. Basically suspect "every" tantalum capacitor in 
> the unit.
> The easy way to fix the unit is to replace all the tants. 
> Unfortunately  there are a lot of them. The other way to go about it 
> is to check all your supply rails, one of them will almost definitely 
> be low, then unplug one PCB at a time. When the voltage comes back 
> replace every tant on the PCB you unplugged last.
> You can also check each tant with a meter the faulty one will nearly 
> always measure short circuit. The problem with this is that as they 
> are supply decoupling capacitors, they are all in parallel so unless 
> you lift one leg they will all appear short. By the time you have 
> lifted one leg you may as well change the cap.
>
> If you are in the North West UK and still having problems, feel free 
> to contact me off the list and I'm sure I can help.
> I have at present got 10 of these receivers, all of which I have 
> successfully repaired. All bar one were capacitor faults.
>
> The only other thing to check is, has the memory backup battery leaked 
> on the CPU board. This is the first board on the left hand side top of 
> the unit viewed from the front.
>
> Cheers,
> Dave.S
>
>
> Stuart Lamb wrote:
>> Hello Premium RX Group,
>>
>> About five years ago I purchased a Racal 1792 (non-BITE). It worked 
>> fine for
>> a couple of years then the FAULT bar started to flash occasionally. 
>> However
>> I’ve hardly used it in the last three years and when I came to fire 
>> it up
>> recently I was met with the following:
>>
>> *    The FAULT bar on the LCD is blinking continuously. *    Channels 
>> and frequencies can be entered via the keypad but the TUNE
>> function of the VFO doesn’t increment frequencies or channels. *    
>> There is no audio output and the S meter shows no deflection in
>> response to local strong signals. *    Mode, bandwidth and AGC 
>> selection is possible.
>> Please can anyone give me an indication of any known faults that may 
>> account
>> for this behaviour, or clues as to where to start looking?
>>
>> Thanks very much,
>>
>>
>>
>> Stuart
>>
>> No virus found in this outgoing message.
>> Checked by AVG. Version: 7.5.524 / Virus Database: 269.23.6/1404 - 
>> Release Date: 29/04/2008
>> 18:27
>>  
>> _______________________________________________
>> Premium-Rx Mailing List
>> To Post: premium-rx at mailman.qth.net
>> For Info: http://mailman.qth.net/mailman/listinfo/premium-rx
>> Visit the Website: http://www.premium-rx.org
>> Email Help: paul at premium-rx.org
>>
>>
>>   
>
> _______________________________________________
> Premium-Rx Mailing List
> To Post: premium-rx at mailman.qth.net
> For Info: http://mailman.qth.net/mailman/listinfo/premium-rx
> Visit the Website: http://www.premium-rx.org
> Email Help: paul at premium-rx.org
>
>