Jerry,
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
working OK.
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.
Don
NT0F
----- Original Message -----
From: "Dr. Gerald N. Johnson" <geraldj@weather.net>
To: <tentec@contesting.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
OK.
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
and
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
is
the second rig for SO2R RTTY contesting. I had many comments that my
shift
was too wide, way off frequency, etc. However these were intermittent. I
may
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,
the
speech processor appeared to be inoperative, and the S meter was not
reading
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
here
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
working
but no ALC.
Please keep in mind, I am not faulting Ten Tec or their service
department
in any way. Paul gave me the choice of continuing the trouble shooting
and
repair as far as I was willing to pay for. However, he said we could
easily
spend 400 to 500 dollars and possibly end up with a logic board problem
that
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
would
be fixed?? Think about it.
Don
NT0F
----- Original Message ----- From: "Zivney, Terry L."<00tlzivney@bsu.edu>
To:<tentec@contesting.com>
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
seen
any listing of the symptoms (specific problems) that caused the owners
to
send their rigs in for repair. Is there any common problem?
NT0F, what was the original problem?
Terry Zivney, N4TZ
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