Sanyo DS-31650 shutdown - here we go again! :)

[BigMike]

Hey guys, left a post about this Sanyo 31" DS31650 TV a while back, that had
a bad flyback and HOT. After replacing the set would turn on, but only for
about 3 seconds and then turnoff. Repeating pressing of the on switch will
get the tube to light up enough to show there is a raster, but no video.
Sound is fine. The customer decided to buy a new set right after this one
was brought in to me, and said he was in no hurry to fix it, so I set it
back while I had more pressing things to work on. Now I would like to get it
out of the shop. Before I order a schematic on this thing, I was wondering
if anybody had at least enough info on this chassis for me to take a crack
at fixing it without the schematic. The problem is the set won't stay on
long enough to do much. I'm sure the micro is tripping the set and shutting
it off, but I don't know if it might be the micro itself, which some have
claimed to replace and solve this problem, or whether the lack of a video
signal, is tripping the micro. If anybody has any info, schematic, or at
least the correct voltage points/waveforms to check that would cause the
micro to shut down, it would be appreciated. If not, I'll probably just
order the schematic and a new micro. I just hate rapping much money up in
this thing, since I doubt it will have all that much more life left in it.
Thanks!

 

[David]

If it is on 3 seconds or so, the micro is not seeing either the h-pulse or
the v-pulse to tell it that both circuits are running. Since the flyback
was back look for a line that goes to a zener diode that gets buffered and
goes to the micro for the h-sync pulse.

David

BigMike <bigmike@cornhusker.net> wrote in message
news:3f0dc4cf$0$11774$9a6e19ea@news.newshosting.com...

Hey guys, left a post about this Sanyo 31" DS31650 TV a while back, that
had
a bad flyback and HOT. After replacing the set would turn on, but only for
about 3 seconds and then turnoff. Repeating pressing of the on switch will
get the tube to light up enough to show there is a raster, but no video.
Sound is fine. The customer decided to buy a new set right after this one
was brought in to me, and said he was in no hurry to fix it, so I set it
back while I had more pressing things to work on. Now I would like to get
it
out of the shop. Before I order a schematic on this thing, I was wondering
if anybody had at least enough info on this chassis for me to take a crack
at fixing it without the schematic. The problem is the set won't stay on
long enough to do much. I'm sure the micro is tripping the set and
shutting
it off, but I don't know if it might be the micro itself, which some have
claimed to replace and solve this problem, or whether the lack of a video
signal, is tripping the micro. If anybody has any info, schematic, or at
least the correct voltage points/waveforms to check that would cause the
micro to shut down, it would be appreciated. If not, I'll probably just
order the schematic and a new micro. I just hate rapping much money up in
this thing, since I doubt it will have all that much more life left in it.
Thanks!

 

[Mark D. Zacharias]

I think I would check the 200 volt line. The timing sounds about right. Beam
current starts, gets excessive, shuts down.

Mark Z.


"BigMike" <bigmike@cornhusker.net> wrote in message
news:3f0dc4cf$0$11774$9a6e19ea@news.newshosting.com...

Hey guys, left a post about this Sanyo 31" DS31650 TV a while back, that
had
a bad flyback and HOT. After replacing the set would turn on, but only for
about 3 seconds and then turnoff. Repeating pressing of the on switch will
get the tube to light up enough to show there is a raster, but no video.
Sound is fine. The customer decided to buy a new set right after this one
was brought in to me, and said he was in no hurry to fix it, so I set it
back while I had more pressing things to work on. Now I would like to get
it
out of the shop. Before I order a schematic on this thing, I was wondering
if anybody had at least enough info on this chassis for me to take a crack
at fixing it without the schematic. The problem is the set won't stay on
long enough to do much. I'm sure the micro is tripping the set and
shutting
it off, but I don't know if it might be the micro itself, which some have
claimed to replace and solve this problem, or whether the lack of a video
signal, is tripping the micro. If anybody has any info, schematic, or at
least the correct voltage points/waveforms to check that would cause the
micro to shut down, it would be appreciated. If not, I'll probably just
order the schematic and a new micro. I just hate rapping much money up in
this thing, since I doubt it will have all that much more life left in it.
Thanks!

 

[bigmike]

"David" <dkuhajda@locl.net.spam> wrote in message
news:3f0e3906@news.greennet.net...

If it is on 3 seconds or so, the micro is not seeing either the h-pulse or
the v-pulse to tell it that both circuits are running. Since the flyback
was back look for a line that goes to a zener diode that gets buffered and
goes to the micro for the h-sync pulse.

David

Thanks David, I'll give it a look. I have a raster for those 3 seconds,
just no video. However, I can see faint retrace lines in the raster, but
it's hard to tell if that might just be the screen control set too high,
since all I can see on the screen is the on-screen menu for those couple of
seconds. Anyway, I'll check it out. Thanks again.

BigMike <bigmike@cornhusker.net> wrote in message
news:3f0dc4cf$0$11774$9a6e19ea@news.newshosting.com...
Hey guys, left a post about this Sanyo 31" DS31650 TV a while back, that
had
a bad flyback and HOT. After replacing the set would turn on, but only
for
about 3 seconds and then turnoff. Repeating pressing of the on switch
will
get the tube to light up enough to show there is a raster, but no video.
Sound is fine. The customer decided to buy a new set right after this
one
was brought in to me, and said he was in no hurry to fix it, so I set it
back while I had more pressing things to work on. Now I would like to
get
it
out of the shop. Before I order a schematic on this thing, I was
wondering
if anybody had at least enough info on this chassis for me to take a
crack
at fixing it without the schematic. The problem is the set won't stay on
long enough to do much. I'm sure the micro is tripping the set and
shutting
it off, but I don't know if it might be the micro itself, which some
have
claimed to replace and solve this problem, or whether the lack of a
video
signal, is tripping the micro. If anybody has any info, schematic, or at
least the correct voltage points/waveforms to check that would cause the
micro to shut down, it would be appreciated. If not, I'll probably just
order the schematic and a new micro. I just hate rapping much money up
in
this thing, since I doubt it will have all that much more life left in
it.
Thanks!

 

[bigmike]

"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message
news:emwPa.41403$C83.3265891@newsread1.prod.itd.earthlink.net...

I think I would check the 200 volt line. The timing sounds about right.
Beam
current starts, gets excessive, shuts down.

Mark Z.

I'll give it a look. Thanks!

"BigMike" <bigmike@cornhusker.net> wrote in message
news:3f0dc4cf$0$11774$9a6e19ea@news.newshosting.com...
Hey guys, left a post about this Sanyo 31" DS31650 TV a while back, that
had
a bad flyback and HOT. After replacing the set would turn on, but only
for
about 3 seconds and then turnoff. Repeating pressing of the on switch
will
get the tube to light up enough to show there is a raster, but no video.
Sound is fine. The customer decided to buy a new set right after this
one
was brought in to me, and said he was in no hurry to fix it, so I set it
back while I had more pressing things to work on. Now I would like to
get
it
out of the shop. Before I order a schematic on this thing, I was
wondering
if anybody had at least enough info on this chassis for me to take a
crack
at fixing it without the schematic. The problem is the set won't stay on
long enough to do much. I'm sure the micro is tripping the set and
shutting
it off, but I don't know if it might be the micro itself, which some
have
claimed to replace and solve this problem, or whether the lack of a
video
signal, is tripping the micro. If anybody has any info, schematic, or at
least the correct voltage points/waveforms to check that would cause the
micro to shut down, it would be appreciated. If not, I'll probably just
order the schematic and a new micro. I just hate rapping much money up
in
this thing, since I doubt it will have all that much more life left in
it.
Thanks!

 

[bigmike]

"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message
news:80LPa.96158$Io.8286263@newsread2.prod.itd.earthlink.net...

Yeah, now it REALLY sounds like the 200 volt line.

Mark Z.

I have a raster for those 3 seconds,
just no video. However, I can see faint retrace lines in the raster

Yeah, it does. I will try to track it down tomorrow and I'll let you know.

"bigmike" <bigmike@cornhusker.net> wrote in message
news:3f0ef89f$0$11825$9a6e19ea@news.newshosting.com...

"David" <dkuhajda@locl.net.spam> wrote in message
news:3f0e3906@news.greennet.net...
If it is on 3 seconds or so, the micro is not seeing either the
h-pulse
or
the v-pulse to tell it that both circuits are running. Since the
flyback
was back look for a line that goes to a zener diode that gets buffered
and
goes to the micro for the h-sync pulse.

David

Thanks David, I'll give it a look. I have a raster for those 3 seconds,
just no video. However, I can see faint retrace lines in the raster, but
it's hard to tell if that might just be the screen control set too high,
since all I can see on the screen is the on-screen menu for those couple
of
seconds. Anyway, I'll check it out. Thanks again.


BigMike <bigmike@cornhusker.net> wrote in message
news:3f0dc4cf$0$11774$9a6e19ea@news.newshosting.com...
Hey guys, left a post about this Sanyo 31" DS31650 TV a while back,
that
had
a bad flyback and HOT. After replacing the set would turn on, but
only
for
about 3 seconds and then turnoff. Repeating pressing of the on
switch
will
get the tube to light up enough to show there is a raster, but no
video.
Sound is fine. The customer decided to buy a new set right after
this
one
was brought in to me, and said he was in no hurry to fix it, so I
set
it
back while I had more pressing things to work on. Now I would like
to
get
it
out of the shop. Before I order a schematic on this thing, I was
wondering
if anybody had at least enough info on this chassis for me to take a
crack
at fixing it without the schematic. The problem is the set won't
stay
on
long enough to do much. I'm sure the micro is tripping the set and
shutting
it off, but I don't know if it might be the micro itself, which some
have
claimed to replace and solve this problem, or whether the lack of a
video
signal, is tripping the micro. If anybody has any info, schematic,
or
at
least the correct voltage points/waveforms to check that would cause
the
micro to shut down, it would be appreciated. If not, I'll probably
just
order the schematic and a new micro. I just hate rapping much money
up
in
this thing, since I doubt it will have all that much more life left
in
it.
Thanks!