Hi;

Another fun one. Video blinks out every 8 seconds and fades back. Pic
is also a bit low on Y drive, i.e. it's a bit dark and color is a bit
oversaturated with the cust controls centered (exc. pic). OSD is
unaffected.

I scoped the ABL line and I'm not seeimg it, if it were arcing I'd have
a dip in the voltage when the blinkout occurs. It's also not at pin 49
of the jungle IC, in fact it looks like it rises slightly when it
occurs, so this must be from the loss of beam current. In other words I
think this is basically caused by the problem, not the cause of the
problem.

Lacking any inputs to the jungle IC that are changing this way when it
happens and having steady video coming in I decided to change it. No
good.

I ran the set's diagnostic and got :

NO. 23906009
POWER :129
BUS LINE :OK
BUS CONT.:OK
BLOCK : UV V1 V2
QV01 QV01S

Block reads that there is sync to the tuner, but not to the video
inputs, the UV is green and the other two are red. QV01 is green and
QV01S is red. From what I gleaned from a similar service manual this is
normal. It also says that POWER is supposed to read 000. This got
cleared when I reset it and did not come back, but it did read 129
before. Anyone know what this means ?, another great situation where
they tell you how to get into it but leave out a few details.

I noticed the bus is always active in this set, unlike some sets that
settle down if you don't push any buttons. Since the set works and the
controls seem to work I assume this is normal for this set, but does
that mean the data are corrupt ? For example could it setting the pic
control to 0 for a split second and then setting it back properly ?
Being digital, would it fade back in in a few seconds ? Seems to me it
would be right back next data cycle, but who knows ? (who indeed)

Thanx in advance.

JURB

Monitor the screen volts to the CRT, and see if this is steady.

I have seen a weak CRT do this type of thing in many models of sets. The CRT
auto-bias circuit runs out of range to keep the CRT working, and thus starts
to cycle. It only takes a few volts of change at the electron guns to make a
difference.

--

Jerry G.
======


wrote in message
ups.com...
Hi;

Another fun one. Video blinks out every 8 seconds and fades back. Pic
is also a bit low on Y drive, i.e. it's a bit dark and color is a bit
oversaturated with the cust controls centered (exc. pic). OSD is
unaffected.

I scoped the ABL line and I'm not seeimg it, if it were arcing I'd have
a dip in the voltage when the blinkout occurs. It's also not at pin 49
of the jungle IC, in fact it looks like it rises slightly when it
occurs, so this must be from the loss of beam current. In other words I
think this is basically caused by the problem, not the cause of the
problem.

Lacking any inputs to the jungle IC that are changing this way when it
happens and having steady video coming in I decided to change it. No
good.

I ran the set's diagnostic and got :

NO. 23906009
POWER :129
BUS LINE :OK
BUS CONT.:OK
BLOCK : UV V1 V2
QV01 QV01S

Block reads that there is sync to the tuner, but not to the video
inputs, the UV is green and the other two are red. QV01 is green and
QV01S is red. From what I gleaned from a similar service manual this is
normal. It also says that POWER is supposed to read 000. This got
cleared when I reset it and did not come back, but it did read 129
before. Anyone know what this means ?, another great situation where
they tell you how to get into it but leave out a few details.

I noticed the bus is always active in this set, unlike some sets that
settle down if you don't push any buttons. Since the set works and the
controls seem to work I assume this is normal for this set, but does
that mean the data are corrupt ? For example could it setting the pic
control to 0 for a split second and then setting it back properly ?
Being digital, would it fade back in in a few seconds ? Seems to me it
would be right back next data cycle, but who knows ? (who indeed)

Thanx in advance.

JURB