Sony KV-24FS120 Video Blanking (and what is IK Shutdown?)

[Frank]

Hi Everyone,

Here's the scoop. I've got a Sony KV-24FS120 TV which after being on
for several hours, begins to blank the video for several seconds while
flashing what I understand is a diagnostic code, then pops the video
back on. Once the cycle starts, it does not stop. The interval between
blank screens appears to depend on the brightness of the picture. While
all this is happening, the audio is fine, and I do not notice any
stopping of the HV whistle.

If I understand the diagnostic blinking correctly, the problem is B+ OCP
(blinking twice), and B+ OVP (blinking three times). With each
fault, either two or three blinks occurs. Once or twice the LED blinked
four times.

Bringing up the diagnostic screen (Disp, 5, Vol-, Pwr), lists the
following information:

2: +B OCP 0
3: +B OVP N/A
4: VSTOP 0
5: AKB 1
101: WDT N/A

Yup, I agree these settings don't agree totally with the # of blinks.
When I first noticed the blinking pattern (I'm new to this whole
diagnostic blinking thing), there **may** have been one time it blinked
five times (explaining the AKB '1').

So, with all my hot air above, are there any suggestions?

Also, just what does the "IK" in "IK Blanking" mean? I've Googled and
Googled, but no definitions.

Thanks a bunch!

-Frank
Holland, PA

 

[[email protected]]

I = Current K = Cathode
AKB failure is related directly to the current being sensed off the
picture tube during the three scan lines checked during the vertical
interval.

Usually in a Sony it is due to the picture tube having cathodes that
are so unabalanced in current that the AKB circuit cannot compensate
and provide a balanced gray scale, hence they blank the video.
Basically the AKB circuit and video drive circuits including the
voltages all need checked per the Sony training manual.

Lots of postings here regarding AKB and Sony video blanking. Do a
Google groups search.