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Help - My old sony Trinitron TV wont tune into any channels

S

Salgaller

Jan 1, 1970
0
Dear sony boff,

I have an old Sony Trintron and it has literally gone on the blink. When I
press the channel button too far it seems to not be able to tune back in again.
I have a clicking number 29 on the panel and thats all. The screen is blank and
the video machine is totally ignored.

How can I get my TV back in again, i've pressed all the buttons and there is
not change.

Please help. Someone. Anyone.

V Salgaller
 
S

sofie

Jan 1, 1970
0
Salgaller:
Gosh..... it sounds like you have a faulty tuner module or a variety of
other possible faults..... you would be best advised to take your
television to a service shop for a repair cost estimate so you can make an
intelligent repair decision with facts instead of internet or telephone
guesses.
Furthermore..... it should be obvious to you that there have been MANY MANY
models of "old Sony Trinitron TVs" manufactaured over the years. If you
are hoping for anything close to a specific repair suggestion you MUST post
the all important MODEL NUMBER and approxiamately how old the television is.
Best Regards,
Daniel Sofie
Electronics Supply & Repair
 
H

Heinz Schmitz

Jan 1, 1970
0
I have an old Sony Trintron and it has literally gone on the blink. When I
press the channel button too far it seems to not be able to tune back in again.
I have a clicking number 29 on the panel and thats all. The screen is blank and
the video machine is totally ignored.

Got the same/similar problem. Stuck on channel 19.
Sony KV-2056EC RM-635 AEP Model, Chassis No. SCC-507A-A.
Not quite recent product, but I love it, because it does look nice
design-wise.

Since I've got the (voluminous) service manual, I took a look into the
device, which is not quite trivial due to the exorbitant amount of
cross-boards-cabling that Sony used here.

The info from the keys seems to be processed in a (4-bit?)-CPU with
internal ROM and stored in a separate serial RAM-chip. I'll have to
verify, wether the processor does get input (would be fault of the
keys or related circuitry) or wether the processor itself is dead.
In the latter case I wonder, if I would be able to obtain a
replacement chip and from whom?
Best wishes,
H.
 
J

James Sweet

Jan 1, 1970
0
Heinz Schmitz said:
Got the same/similar problem. Stuck on channel 19.
Sony KV-2056EC RM-635 AEP Model, Chassis No. SCC-507A-A.
Not quite recent product, but I love it, because it does look nice
design-wise.

Since I've got the (voluminous) service manual, I took a look into the
device, which is not quite trivial due to the exorbitant amount of
cross-boards-cabling that Sony used here.

The info from the keys seems to be processed in a (4-bit?)-CPU with
internal ROM and stored in a separate serial RAM-chip. I'll have to
verify, wether the processor does get input (would be fault of the
keys or related circuitry) or wether the processor itself is dead.
In the latter case I wonder, if I would be able to obtain a
replacement chip and from whom?
Best wishes,
H.

With weird problems like this it's always best to start by verifying the
power supply, check the voltages and look for bulging or leaking
electrolytic capacitors, a low voltage or lots of ripple can cause all sorts
of apparently random problems. Also I assume you've tried unplugging it
overnight?
 
H

Heinz Schmitz

Jan 1, 1970
0
With weird problems like this it's always best to start by verifying the
power supply, check the voltages and look for bulging or leaking
electrolytic capacitors, a low voltage or lots of ripple can cause all sorts
of apparently random problems. Also I assume you've tried unplugging it
overnight?

Everything else works. High voltage is present, voltages are in range,
even the quartz for the processor is oscillating as it should. I
didn't do all the measurements during one day, so it did sleep
unplugged before being questioned further :).
As the tuner gets its freq-control-voltages from the processor, the
fault is definitely in the chain keys->cpu/RAM->tuner.
H.
 
N

Nigel

Jan 1, 1970
0
Got the same/similar problem. Stuck on channel 19.
Sony KV-2056EC RM-635 AEP Model, Chassis No. SCC-507A-A.
Not quite recent product, but I love it, because it does look nice
design-wise.

Usual problem on those was failure of one or more of the front panel
switches. They stay shorted and inhibit signals from any other keys or the
remote. Test them all, even the ones that aren't associated with the tuning
or programme selection.

Let me know if that is not the cause and I'll find some additional info for
you.
 
H

Heinz Schmitz

Jan 1, 1970
0
Usual problem on those was failure of one or more of the front panel
switches. They stay shorted and inhibit signals from any other keys or the
remote. Test them all, even the ones that aren't associated with the tuning
or programme selection.

Let me know if that is not the cause and I'll find some additional info for
you.

Hey, thanks for the tip. Testing the keys does sound much easier then
testing the processor :). Will keep you informed, but it may take
some time due to other patients waiting on the bench :-(.
Best regards,
H.
 
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