Many of the later model Sony TV's have a built in Self- Diagnosis
function. If the timer/standby indicator is blinking, this
could be an indication of the problem with the unit. The diagnostic
blinking will occur automatically with no action
required by you to engage it.
The timing of the blinking you see would be as follows: two to eight
blinks (depending on the fault) about a third of a
second apart, then pauses for 3 seconds, then the two to eight
blinks about a third of a second apart again.
Here is a list of the problems that might have occurred indicated by
the number of blinks. The words in parentheses are
those which you will see for each of these faults on a diagnosis
screen described later in this article.
Unit is dead and there are no blinks---Problem in the standby power
section. Might check fuse, R607, Q601, IC601, R612
and VDR601 (should show open)
Continuous Blink Once A Second, No Pausing As Discussed Above---
No reply from the jungle IC301 (data bus is busy, shorted to ground
or held high), IK video path is defective.
ONE Blink--- not used for the self-diagnosis
TWO Blinks---B+ over current protection (OCP) , unit goes to the
standby mode then displays the 2 blink fault. Could be a
short in the power supply of any of the circuits.
THREE Blinks---B+ over voltage protection (OVP), unit goes to the
standby mode then displays the 3 blink fault. This is
also a problem in the power supply circuit, check T603 and R672.
FOUR Blinks---No Vert. Deflection (V STOP), Screen goes to a single
horizontal line then the video signal muted. Check
FIVE Blinks---AKB circuit (AKB), the timer/standby indicator blinks
for about 30 seconds then goes to the self-diagnosis
function. Something is wrong with the video. Check video out, Q705,
732, 761 and other components on the C board, also check
Q218, 219, 220 on the A board. Also unit be in IK blanking, try
turning up screen slightly.
SIX Blinks---No Horizontal (H STOP), no raster, goes to the blinking
self-diagnosis function immediately. Check C515 & 516
and the jungle IC, IC206.
SEVEN Blinks---High voltage shutdown. The high voltage has exceeded
33k and the unit goes immediately into safety shutdown.
Check power supply regulation and horizontal circuits.
EIGHT Blinks---Problem with the audio (AUDIO), unit goes to standby
and blinks the self-diagnosis code. Check IC406 audio
amp, PS401 and 402.
Intermittent problems ?? This is a great feature. You can also bring
up these fault codes ON-SCREEN to see a list of the
problem numbers with the abbreviation of the problem and the number
of times this problem has occurred. This is slightly
different than entering the service mode. To see the diagnostic
screen, Press the following buttons:
Display, Channel, 5, Vol Minus, ( Not plus ) then Power. This brings
up a screen with a list of the problems and number
of times they have occurred. Each of the problem names is abbreviated
as, " OCP " , " OVP " , " V STOP " , ETC. We have repeated
them in parentheses in the text for the " Blinks " described above so
you can correlate between the diagnostic screen and
the blink codes.
So, now that you know about these self-diagnostics, how do you use
them? Say that you have a set with a black screen. You
see that the LED is blinking 4 times....This would tell you that you
have no vertical and that is why the video is muted.
If it was blinking 6 times, you would know that you have a
It's not a sure cure, but it's a little better than a poke in the eye
with a sharp stick.
IMPORTANT: after you repair the unit, PLEASE clear the values on this
diagnostic screen. These codes do not reset
themselves after the fault is corrected, so if you don't clear them,
you'll be seeing " old " fault codes the next time
you enter this screen.
Clearing is done by going into the service mode ( display, channel,
5, volume plus, then power ) then press 8 and Enter,
which of course returns everything to the factory preset condition.