[TenTec] Recalcitrant Orion

Sat Aug 6 12:38:07 EDT 2016

I have already replaced the cap and the reset device. 

I have also tried directly reseting the CPU at this point by pulling the cap low with a shorting wire. This has worked on other Orion’s but only partially works with this one.

Gary

> On Aug 6, 2016, at 11:31 AM, Katz Ajamas <ajamas.rn at gmail.com> wrote:
> 
> Replacing all the caps! No Way!. Maybe testing a few.
> If you have dual trace scope with trigger, you can look to see if the CPU is resetting. If not, I would suspect this small circuit. Note the timing admonition on the schematic!
> 
> Copy attached.  Let us know. My 565 still needs repair!
> 
> 73, -Bob
> 
>  
> > On Aug 5, 2016, at 11:09 AM, Katz Ajamas <ajamas.rn at gmail.com <mailto:ajamas.rn at gmail.com>> wrote:
> >
> > So what was wrong? CPU power on reset problem? Please share.
> > 73, -Bob ah7i
> > _______________________________________________
> > TenTec mailing list
> > TenTec at contesting.com <mailto:TenTec at contesting.com>
> > http://lists.contesting.com/mailman/listinfo/tentec <http://lists.contesting.com/mailman/listinfo/tentec>
> 
> 
> 
> ------------------------------
> 
> Message: 5
> Date: Fri, 5 Aug 2016 22:47:32 -0500
> From: Gary J FollettDukes HiFi <dukeshifi at comcast.net <mailto:dukeshifi at comcast.net>>
> To: Discussion of Ten-Tec Equipment <tentec at contesting.com <mailto:tentec at contesting.com>>
> Subject: Re: [TenTec] Orion II repair
> Message-ID: <0141B9C2-28C8-4211-BE27-3DA03028E199 at comcast.net <mailto:0141B9C2-28C8-4211-BE27-3DA03028E199 at comcast.net>>
> Content-Type: text/plain; charset=utf-8
> 
> To clarify, for the more well advance EE?s out there, what I called an I/O controller is actually a complex programmable logic device (CPLD).
> 
> It is, however, so far as I can tell, acting as traffic cop for the CPU.
> 
> Gary
> 
> 
> > On Aug 5, 2016, at 10:19 PM, Gary J FollettDukes HiFi <dukeshifi at comcast.net <mailto:dukeshifi at comcast.net>> wrote:
> >
> > I still don?t know.
> >
> > Here is an update o the rather strange behavior:
> >
> > I already swapped power distribution board, button board and CPU board. A different CPU board operates properly in the radio. perfectly.
> >
> > Here is the sequence:
> > 1) Cold startup  normal boot up sequence, receives signals, none of the encoders except VFO?s work, none of the pushbuttons work.
> > 2) Connect to N4PY software and connect, most functions work but not necessarily correctly. Tuning rate is very slow and some buttons do not do  what they should.
> > 3) Shut down for maybe 30 minutes.
> > 4)  Cold startup  normal boot up sequence, receives signals, none of the encoders except VFO?s work, none of the pushbuttons work.
> > 5) Wait 15 minutes, everything works fine.
> > 6) Shut down for maybe 30 minutes.
> > 7)  Cold startup  normal boot up sequence, receives signals, none of the encoders except VFO?s work, none of the pushbuttons work.
> > 8) Wait 15 minutes, everything works fine.
> >
> > Now, if I operate the encoders while the radio is ignoring them, then wait out the 15 minutes, the radio responds just as if I had just taken those actions. That is, if I turn the volume down while the radio is not responding, the volume will drop once the radio starts working. Ditto for all other encoders. So data is getting to the I/O controller, just not being sent to the CPU. In this state, the actions of pushbuttons are NOT saved, however.
> > One thing that is different about the VFO encoders, both of which always work, and the 6 small encoders is that the VFO encoders are pull high devices operating from the R5 volt supply. The 6 small encoders are pull down devices with outboard pulp resistors also operating from the R5 volt supply.
> >
> > If I operate the encoders in the first fractions of a second after boot up, before the S meter makes is normal bump swing to the right, the encoders work but stop working after that bump.
> >
> > The delay to normal operation is pretty repeatable. It acts as if there is a high resistance somewhere and a capacitors is charging up to enable the CPU to see data that is in the I/O controller.
> >
> > I really doubt that this is a thermal issue or a CPU or I/O controller issue. I am contemplating simply replacing all of the capacitors on the CPU board.
> >
> > Gary
> >
> >
> >
> >> On Aug 5, 2016, at 11:09 AM, Katz Ajamas <ajamas.rn at gmail.com <mailto:ajamas.rn at gmail.com>> wrote:
> >>
> >> So what was wrong? CPU power on reset problem? Please share.
> >> 73, -Bob ah7i
> >> _______________________________________________
> >> TenTec mailing list
> >> TenTec at contesting.com <mailto:TenTec at contesting.com>
> >> http://lists.contesting.com/mailman/listinfo/tentec <http://lists.contesting.com/mailman/listinfo/tentec>
> >
> <Power on reset main board..png>