[TenTec] Orion II repair

[Gary J FollettDukes HiFi]

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> 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> wrote:
>> 
>> So what was wrong? CPU power on reset problem? Please share.
>> 73, -Bob ah7i
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