Here is what I have found so far. I opened up the rig, verified I was
getting 13.6 volts to the logic board on connector 2. When I turned the rig
on, the lower section of the display was out, the unit would loose audio,
keypad and encoders locked up, etc. I verifed that when the audio went away,
I could pull off the 2 mini coaxs at 54 and 56, hook them together to bypass
the DSP and audio returned. I decided to look at one thing at a time. I
found that the display output from the logic board was on connector 90. I
preesed on that connector. It was not fully seated, and when it did, the
display lit up, and it appears all funtions were back to normal. I left the
power supply on with the rig off, overnight. Yesterday while doing BARTG
RTTY Sprint, I had the rig on most of the day and it never lost audio,
locked up, all appeares OK. I shut everything down. I came down Sunday after
lunch and turned the rig on. All was OK for a few minutes, then the audio
went away and the keypad and encoders locked up again. I turned off the rig
and decided to leave the power supply on to keep the crystal oven heating
up. I waited about 30 minutes, turned the rig back on, and so far it is
This leads me to believe, as you stated, the time base is where a lot
of the problem lies. I am going to order and replace the TXCO, order the
precision BFO crystals and align those 2 portions of the rig. I have not
went any deeper than that.
----- Original Message -----
From: "Dr. Gerald N. Johnson" <email@example.com>
Sent: Friday, January 21, 2011 7:22 PM
Subject: Re: [TenTec] Symptoms of logic board failure
> The time base messes up the processors, both control and DSP. Likely the
> buttons are side effects of the control processor running poorly. And
> that could be an effect of the FSK also. Flickering meter lamps points
> to a power supply problem that might be what ails the control board.
> ALC might be a separate ailment from nearby lightning having fried the
> ALC detector diodes, its happened to many a Tentec.
> Not everyone working RTTY knows what shift is or how to tell if its wide
> or not, especially with computer based RTTY. Hardware terminal units
> displayed shift as a normal function.
> 73, Jerry, K0CQ
> On 1/21/2011 7:26 AM, Don Steele wrote:
>> The original problem started during to 10 meter contest. All was working
>> I took a short break, and when I came back, the audio was dead on the
>> rig. I
>> cycled power, and at that point, the rig would not power up. No audio, no
>> display, and every LED indicator came on. Also the meter lamps were very
>> dim. I verified 13.66 volts out of the power supply, pulled the covers
>> could find no obvious issues with a quick look around.
>> However, before this all occurred, I was having issues with the rig,
>> which may or may not be related to the logic board. Most of this rigs use
>> the second rig for SO2R RTTY contesting. I had many comments that my
>> was too wide, way off frequency, etc. However these were intermittent. I
>> have made 30 or 40 qso's and only have 1 or 2 comments. Was it bad every
>> time? I do not know. I also has flickering meter lamps, with new bulbs,
>> speech processor appeared to be inoperative, and the S meter was not
>> correctly, mostly stuck at about s 5 with very little movement. I do not
>> know,yet,if any of this was related to the logic board.
>> I received the rig back this week and hope to begin some testing
>> myself this weekend. I will keep the list informed if I can find any
>> issues.I am not a fully trained service tech and do not have any test
>> equipment other than a good multimeter, so I will be limited in how far I
>> can go with this.
>> Here is the list of problems from the service department at Ten Tec.
>> Rid has several major problems.
>> 1.Time base (Logic Board) hard to start and will drop out.
>> 2. Key pad will lock-up
>> 3. Display missing "D" segment
>> 4. Audio will drop out.
>> 5. TX?Audio board needs 1 or 2 crystals,RX and PLL not tested,RF amp
>> but no ALC.
>> Please keep in mind, I am not faulting Ten Tec or their service
>> in any way. Paul gave me the choice of continuing the trouble shooting
>> repair as far as I was willing to pay for. However, he said we could
>> spend 400 to 500 dollars and possibly end up with a logic board problem
>> they could not fix. Stopping where they did was my choice financially. As
>> has been mentioned these are around a 1000.00 dollar rig used. Would you
>> spend up to 500.00 out of your pocket, with no guarantee that the rig
>> be fixed?? Think about it.
>> ----- Original Message ----- From: "Zivney, Terry L."<firstname.lastname@example.org>
>> Sent: Wednesday, January 19, 2011 4:56 PM
>> Subject: [TenTec] Symptoms of logic board failure
>>> I have seen lots of postings about "logic board failures" but haven't
>>> any listing of the symptoms (specific problems) that caused the owners
>>> send their rigs in for repair. Is there any common problem?
>>> NT0F, what was the original problem?
>>> Terry Zivney, N4TZ
>>> TenTec mailing list
>> TenTec mailing list
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