Sony KV-32FV27

OK, here's one creating a time warp around my workbench:

Good sound, no picture via any input. Good raster and good OSD,
full menu, no failure events appear in diagnostic menu. No strange
numbers in service menu for cutoff, gain, sub brightness etc.

Just like Ik shutdown, but no blinks. If I disable
Ik detector then jungle tells uP which then does five blinks.
So have 2 way communication: Jungle -- uP.

Upon startup have large Ik pulses on each cathode which shrink as
emission comes up.

Have good Y and C entering jungle, H and V circuits sync up.
Tried PIP but still totally blank screen. "No Signal" message
goes away with active input.

So, looks like uP not bothering to issue PON, or, it does issue
PON but jungle is out to lunch. I do not have a I2C monitor.

Another possibility I suppose is that blanking is stuck somehow.

Am I overlooking something obvious? What other status bits
does the uP check before turning video on in this model?

Many years ago, I used to service these under a warranty contract.

I serviced many Sony models. I am going to try to go by memory here.

I am assuming from your description that you have a raster because you have
the OSD. This means that the main scans and the video path should be working
from the font generator. On the video input of this set, there is an input
switching IC. I have had these fail, and this produced no video, but OSD. I
am assuming you properly checked that all the voltages leaving the power
supply are correct.

On the flyback secondary output side, there are a number of different
voltage outputs used to operate the front end areas, such as the video input
section, including the input switching IC circuits, and also to operate the
tuner and IF sections. Make sure that no voltages are missing. Along their
path, I am sure that there are some voltage regulators. I have seen some
problems in those sections as well.

If the IF module is defective, it is possible, depending on the nature of
the failure, there may be a loss of any type of composite video input or
tuner video. I have had to change this module, and including the tuner
module in these sets.

Here at home, I am still using a KV20V60 from 1997. It is a great set, and
it is still going strong. I also have an old KV27XBR50 from 1992. This one
is a terrific set. About 8 years ago, I had to rebuild the main power
supply in the XBR. I was no longer able to buy the complete assembly. In
both of my sets, I installed quiet whisper fans to cool the scan areas and
the power supply area. This will certainly lengthen the life of the sets. I
installed a small separate power supply in each set to run the fans rather
than tap the 12 Volts off the main supplies.

--

Jerry G.
======


wrote in message
ups.com...
Sony KV-32FV27

OK, here's one creating a time warp around my workbench:

Good sound, no picture via any input. Good raster and good OSD,
full menu, no failure events appear in diagnostic menu. No strange
numbers in service menu for cutoff, gain, sub brightness etc.

Just like Ik shutdown, but no blinks. If I disable
Ik detector then jungle tells uP which then does five blinks.
So have 2 way communication: Jungle -- uP.

Upon startup have large Ik pulses on each cathode which shrink as
emission comes up.

Have good Y and C entering jungle, H and V circuits sync up.
Tried PIP but still totally blank screen. "No Signal" message
goes away with active input.

So, looks like uP not bothering to issue PON, or, it does issue
PON but jungle is out to lunch. I do not have a I2C monitor.

Another possibility I suppose is that blanking is stuck somehow.

Am I overlooking something obvious? What other status bits
does the uP check before turning video on in this model?