Here is a second occurance of the 9 blink ZDC failure. These are not
my words but someone that spent time enough to document this symptom
and post it on Sony's web site.

SYMPTOMS

9 Blinks

RESOLUTION

Z-Det waveform was present, although with no reference, could not tell
if it was correct.
Replaced D640 & D641, then D646, Q690 & Q646, then all the 10k chip
resistors in that circuit. NO improvement.

Checking the Z-Det waveform at the Collector of Q606 found it to be
about .3ms longer than the defective board. In addition to the
slightly longer waveform, some noise pulses that were present on the
waveforms. Replaced Standby Transformer. It did not help. Also tried
D602, no help.

I found the noise was greatest on pin 7 of the Standby Transformer.
Disconnected D647. Noise gone. Replaced (new) D647. Noise is back.
Replaced Q605 and noise was gone and set working again. Apparently,
one of the junctions was flaky at certain voltage levels, causing
noise (change in load) on the collector that was seen back through the
Standby Transformer and was causing the ZCD circuit to malfunction.


Have subsequently found that a bad Q605 can generate the above
mentioned noise pulses. Replacing Q605 cured the problem. A bad D690
could also cause the problem