[Drake] Re: RR3 Digital Control Board replacement

[James C. Garland]

At 04:24 AM 10/1/2003, you wrote:
>Cornell, PA3BTS, asked:
>
> > After an extensive fault search in my RR3 receiver (maritime
> > version of the R7) it seems that the Digital Control Board
> > is faulty, most probably the PROM IC type (N)82S123(N).
> > Can anyone give me a source for a replacement board or a
> > replacement IC? Is it necessary to program the IC and if so,
> > with which information?
Hi Cornell,
Although I don't have knowledge of the RR3, in my experience, PROMS and 
EPROMS seldom fail. Most of the time, problems that I initially think are 
PROM-related turn out to be an interface support chip.  Unfortunately, it's 
hard to troubleshoot these circuits.  Usually, an address or data line will 
be dead (showing either 0 or +5), but since several chips are connected to 
the lines, it's not easy to know which one is causing the problem.  My 
point is simply not to focus in on the PROM prematurely. Good luck!
73,
Jim Garland W8ZR