"Mark Zacharias" wrote in message
...
"Arfa Daily" wrote in message
...

"Meat Plow" wrote in message
...
On Sun, 8 Nov 2009 01:41:13 -0000, "Arfa Daily"
wrote:


"b" wrote in message
...
On 7 nov, 17:12, "David B." wrote:stanby light
flashes 7 times.
Does anyone knowwhat would cause the above issue and how I could fix
it?

yeah. it's broken.

seriously now, you will need to get in there and measure a few
voltages , test a few components and at least give us the chassis
reference if you expect any more detailed help than the above!

Flashing LEDs can mean almost anything, from a dry joint to a
transformer failure, and are not a relaible guide. If I were you, I
would take the set to a local repair place and get a quote, based on
proper diagnosis rather than any internet guesswork. The inside of a
TV is no place to be if you have no electroncis experience.

best of luck.
-B

With Sony TV sets, the number of times that the LED blinks, is generally
a
code to refer you to the faulty area. ISTR that 7 flashes indicates a
horizontal deflection failure, so I guess that the first favourite would
have to be the HOP transistor short circuit, although be aware that
there
are issues which can cause transistor failure.


Like the driver/driver coupling.

Yes, quite so. Anything in the base coupling circuit which slows the
transition of the drive waveform will do it. Also bad joints on the
driver transformer when one is used, bad joints on the driver transistor,
faulty flyback tuning caps, faulty HOPTx, and incorrect HT volts to name
a few more common ones.

Arfa


Worked on quite a few of these the past couple years. IC8002 is a frequent
offender. These models are quite different from the standard issue type
we've seen for so many years. I'm actually a relative newbie on TV's,
having been "promoted" to working on them in-shop with the other guys
always out on service calls, but just to give you an idea how different
these sets are from the norm, I can tell you the high voltage is a
complete separate circuit from the 200 volt line. This is because of the
different scan rates supported.

IC8002 provides the PWM drive for the high voltage. IC6501 relates to the
200 volt line. The typical failure mode is that sometimes the set will
fire up just fine, then maybe not for days on end, then mysteriously start
working again, sometimes for up to a couple months.

If the white 0.1 ohm Micron resistors are OK, then IC8002 is by far the
most likely suspect. If the 0.1 resistor associated with that set of FET
switchers is open, then of course those transistors are bad. This seems to
be the case only very rarely, mainly if the flyback(LOPT) goes tango
uniform.

The IC's involved, again are generically known as MCZ3001D and should be
replaced with the newer DB suffix model.

Mark Z.

Aha ! I bow to your definitely superior knowledge on this chassis then Mark.
It's not one that I've had cause to work on I think - in fact nowadays, I
try to steer clear of TV sets altogether. I was just thinking back to all
the Sony models with the LED flash codes, and remembering (I think) that 7
flashes was a H def failure, when the HOP and HV were all part and parcel of
the same stage.

Arfa