GE PROJECTION TV

L

LawyerKill

Guest
LK

Hi I have an old(about 25 years) GE Projection TV. There is a circuit breaker
in the back for the horizonal output circuit. I turn the TV on, get audio, but
before I get a picture the CB pops. I checked the Filter Caps and they are OK.

Question: If the Flyback was bad would the CB pop when you first turn the TV
on, or pop after about 10 seconds like it's doing?
 
I have seen these mechanical breakers themselves go defective. You should
find out exactly how much current the circuit after the breaker is supposed
to be pulling, and verify that. If the current pull is too high, you can
work from there. If it is normal, then the breaker has to be changed. I
have seen these breakers go defective, and become easy to trip.

The fault may be some high ESR caps in the scan outputs, or anywhere after
the breaker. Even a cap somewhere that is going resistive (internal
leakage) that is causing too high a current pull, can cause the breaker to
trip. It is possible that a bias resistor on a power device is going off
value, thus causing it to pull too much current.

If the picture is normal, chances are that the flyback and HV module is
okay. This has to be determined.

To work on your set, you will need the proper training, service manual, and
tools.

NEVER jump that breaker. If you do, and there is a defect, then the failure
will be catastrophic, thus doing a lot of component damage.

Considering that the set is 25 years old, it will probably be impossible to
find many of the specialized parts. Only the generic parts such as the
standard resistors, most of the semiconductors, and caps would be available.
As for transformers, custom devices, mechanical parts, and etc, these will
be almost impossible to have. The tubes must also have signs of wear on
them as well.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"LawyerKill" <lawyerkill@aol.com> wrote in message
news:20031128233609.28534.00001101@mb-m14.aol.com...
LK

Hi I have an old(about 25 years) GE Projection TV. There is a circuit
breaker
in the back for the horizonal output circuit. I turn the TV on, get audio,
but
before I get a picture the CB pops. I checked the Filter Caps and they are
OK.

Question: If the Flyback was bad would the CB pop when you first turn the TV
on, or pop after about 10 seconds like it's doing?
 
LawyerKill wrote:
LK

Hi I have an old(about 25 years) GE Projection TV. There is a circuit breaker
in the back for the horizonal output circuit. I turn the TV on, get audio, but
before I get a picture the CB pops. I checked the Filter Caps and they are OK.

Question: If the Flyback was bad would the CB pop when you first turn the TV
on, or pop after about 10 seconds like it's doing?
Click to expand...
I would expect a shorted HOT to pop it in less than a second, but a bad
flyback (depending on how bad) could cause this. Do you get HV? You
can always put an ammeter in series with it to see what the current
really is. A short, or overload on one of the flyback secondaries would
cause this type of thing. A shorted yoke is another possibility. On a
25 year old GE, the first thing I would do is check the soldering very
carefully, ESR the caps and resolder any through board connections if it
uses double sided boards.
--
Andy Cuffe
baltimora@psu.edu
 
Didn't GE put out a rear projection tv from a very long time ago that was
actually an overdriven 13" tv set with a big lens? I seem to recall seeing
someone try and bring one of those in for repair several years ago.

David

Jerry G. <jerryg50@hotmail.com> wrote in message
news:bqa708$bo5$5@news.eusc.inter.net...
I have seen these mechanical breakers themselves go defective. You should
find out exactly how much current the circuit after the breaker is
supposed
to be pulling, and verify that. If the current pull is too high, you can
work from there. If it is normal, then the breaker has to be changed. I
have seen these breakers go defective, and become easy to trip.

The fault may be some high ESR caps in the scan outputs, or anywhere after
the breaker. Even a cap somewhere that is going resistive (internal
leakage) that is causing too high a current pull, can cause the breaker to
trip. It is possible that a bias resistor on a power device is going off
value, thus causing it to pull too much current.

If the picture is normal, chances are that the flyback and HV module is
okay. This has to be determined.

To work on your set, you will need the proper training, service manual,
and
tools.

NEVER jump that breaker. If you do, and there is a defect, then the
failure
will be catastrophic, thus doing a lot of component damage.

Considering that the set is 25 years old, it will probably be impossible
to
find many of the specialized parts. Only the generic parts such as the
standard resistors, most of the semiconductors, and caps would be
available.
As for transformers, custom devices, mechanical parts, and etc, these will
be almost impossible to have. The tubes must also have signs of wear on
them as well.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"LawyerKill" <lawyerkill@aol.com> wrote in message
news:20031128233609.28534.00001101@mb-m14.aol.com...
LK

Hi I have an old(about 25 years) GE Projection TV. There is a circuit
breaker
in the back for the horizonal output circuit. I turn the TV on, get audio,
but
before I get a picture the CB pops. I checked the Filter Caps and they are
OK.

Question: If the Flyback was bad would the CB pop when you first turn the
TV
on, or pop after about 10 seconds like it's doing?
Click to expand...
 
Subject: Re: GE PROJECTION TV
From: "David" dkuhajda@locl.net.spam
Date: 11/29/03 4:55 PM Eastern Standard Time
Message-id: <3fc94ced@news.greennet.net

Didn't GE put out a rear projection tv from a very long time ago that was
actually an overdriven 13" tv set with a big lens? I seem to recall seeing
someone try and bring one of those in for repair several years ago.

David
Click to expand...
Dear God yes! I remember those too. The cabinets were "L" shaped as the 13"
TV part was stuffed off to the side. The focal length must have been 10 feet!
They had a crappy picture even when new.
My guess is that the poster's TV is actually a Panasonic. I fixed a couple of
GEs years ago that were.
John Del
Wolcott, CT

"I'm just trying to get into heaven, I'm not running for Jesus!"
Homer Simpson

(remove S for email reply)
 
David
Didn't GE put out a rear projection tv from a very long time ago that was
actually an overdriven 13" tv set with a big lens? I seem to recall seeing
someone try and bring one of those in for repair several years ago.
Click to expand...
LK

That's the one, the only reason I'm trying to repair it is that I have no one
here to help me push it out the door and onto the sidewalk.
 
Just out of curiousity, do you (or anyone) have any web resources showing
photos of this contraption?

Are you in a position to take and upload photos somewhere?

Thanks,
-Steve


"LawyerKill" <lawyerkill@aol.com> wrote in message
news:20031205180240.28525.00000238@mb-m01.aol.com...
David
Didn't GE put out a rear projection tv from a very long time ago that was
actually an overdriven 13" tv set with a big lens? I seem to recall
seeing
someone try and bring one of those in for repair several years ago.


LK

That's the one, the only reason I'm trying to repair it is that I have no
one
here to help me push it out the door and onto the sidewalk.
Click to expand...

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.547 / Virus Database: 340 - Release Date: 12/2/2003
 
Andy Cuffe
I would expect a shorted HOT to pop it in less than a second, but a bad
flyback (depending on how bad) could cause this. Do you get HV? You
can always put an ammeter in series with it to see what the current
really is. A short, or overload on one of the flyback secondaries would
cause this type of thing. A shorted yoke is another possibility. On a
25 year old GE, the first thing I would do is check the soldering very
carefully, ESR the caps and resolder any through board connections if it
uses double sided boards.

LK

Thank Andy, it turns on and you can hear a whine for about 15 seconds, the
audio is loud, after 15 seconds the circuit breaker pops and the audio drops to
about half of what it was, the screen never gets a raster.

The breaker is OK, I checked that.

I disconnect the voltage from the horizontal output and measure it and it's a
nice 140 VOLT, I hook it back up and turn it on and it's about 85 volt until
the CB goes, it's drawning 2.5 amps. I put a scope on the Horizontal output
transistor and it looks like I'm getting the wave form that I should (The set
came with service information). I measured all the diodes and resistors in the
Horizontal section and they appear OK, the Driver and Output transistors check
OK with an ohm meter.

There's a lead coming out of the flyback and it shows 4 diodes on the winding
where that lead is, I took it off and laid it on that side, turned the TV on
and it started arcing about 3 inches to the chassis, so I guess I have HV.

I'm not a TV guy, I have an FCC First Class that I got in 1969 but I went right
into engineering(Logic circuits) and I forgot most of the TV stuff.

Now I'm measuring my doorway and distances to the sidewalk.
 
Steve Reinis
Just out of curiousity, do you (or anyone) have any web resources showing
photos of this contraption?

Are you in a position to take and upload photos somewhere?
Click to expand...
LK

I can take a picture of it, if you want, that's no problem.
 
LawyerKill wrote:
LK

Thank Andy, it turns on and you can hear a whine for about 15 seconds, the
audio is loud, after 15 seconds the circuit breaker pops and the audio drops to
about half of what it was, the screen never gets a raster.

The breaker is OK, I checked that.

I disconnect the voltage from the horizontal output and measure it and it's a
nice 140 VOLT, I hook it back up and turn it on and it's about 85 volt until
the CB goes, it's drawning 2.5 amps. I put a scope on the Horizontal output
transistor and it looks like I'm getting the wave form that I should (The set
came with service information). I measured all the diodes and resistors in the
Horizontal section and they appear OK, the Driver and Output transistors check
OK with an ohm meter.

There's a lead coming out of the flyback and it shows 4 diodes on the winding
where that lead is, I took it off and laid it on that side, turned the TV on
and it started arcing about 3 inches to the chassis, so I guess I have HV.

I'm not a TV guy, I have an FCC First Class that I got in 1969 but I went right
into engineering(Logic circuits) and I forgot most of the TV stuff.

Now I'm measuring my doorway and distances to the sidewalk.
Click to expand...

Since you have HV, the flyback is probably ok. What's the circuit
braker rated at? As a LAST resort you could always bypass the circuit
braker and see what smokes. Of course there's a good chance you'll lose
the HOT, or components in the power before learning anything. One thing
to try would be unplugging the yoke and CRT socket (so you don't burn
the CRT screen).
--
Andy Cuffe
baltimora@psu.edu
 
Andy
Since you have HV, the flyback is probably ok. What's the circuit
braker rated at? As a LAST resort you could always bypass the circuit
braker and see what smokes. Of course there's a good chance you'll lose
the HOT, or components in the power before learning anything. One thing
to try would be unplugging the yoke and CRT socket (so you don't burn
the CRT screen).
Click to expand...
LK

Thanks Andy. What I just finish doing was disconnecting all but the drivers for
the HOT and the winding of the flyback for the HOT. Across the HOT there is a
diode, an 300 pf 2kv cap, and a .0145 5% 1.5 kv Cap, that's all, and it still
pops the breaker. Resistance checks of the caps, HOT and diode all appear to be
good. I'm one step away from putting a 15 ohm resistor in line with the power
supply and jumping out the circuit breaker and see which of the few parts left
smoke.
 
If ya don't mind, I'd love to see it. It sounds like such an oddball idea -
using a 13" single CRT for a projection set.

You can email it to:

Ragtop429
@
Hotmail.com

I'd sure appreciate it,
-Steve


"LawyerKill" <lawyerkill@aol.com> wrote in message
news:20031205190554.28525.00000241@mb-m01.aol.com...
Steve Reinis
Just out of curiousity, do you (or anyone) have any web resources showing
photos of this contraption?

Are you in a position to take and upload photos somewhere?

LK

I can take a picture of it, if you want, that's no problem.
Click to expand...

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.547 / Virus Database: 340 - Release Date: 12/2/2003
 
"LawyerKill" <lawyerkill@aol.com> wrote in message
news:20031205180240.28525.00000238@mb-m01.aol.com...
David
Didn't GE put out a rear projection tv from a very long time ago that was
actually an overdriven 13" tv set with a big lens? I seem to recall
seeing
someone try and bring one of those in for repair several years ago.


LK
Click to expand...
They actually sold something like that commercially? Is there any more info
out there?
 
"LawyerKill" <lawyerkill@aol.com> wrote in message
news:20031205190554.28525.00000241@mb-m01.aol.com...
Steve Reinis
Just out of curiousity, do you (or anyone) have any web resources showing
photos of this contraption?

Are you in a position to take and upload photos somewhere?

LK

I can take a picture of it, if you want, that's no problem.
Click to expand...
Yeah I'd like to see this too, very strange, must have had a horrible
picture quality.
 
LK sent me a couple photos of this monster. And what a beast it is, too!
Very 70's looking cabinet. I'll forward them your way. I'd actually love
to strip the guts from the cabinet and stick another pullout style lightbox
in there just to get a functional RPTV with that great (tacky) retro look!
The cabinet looks to be in great shape for the age.

-Steve


"James Sweet" <jamessweet@hotmail.com> wrote in message
news:BvfAb.36298$_M.167275@attbi_s54...
"LawyerKill" <lawyerkill@aol.com> wrote in message
news:20031205190554.28525.00000241@mb-m01.aol.com...
Steve Reinis
Just out of curiousity, do you (or anyone) have any web resources
showing
photos of this contraption?

Are you in a position to take and upload photos somewhere?

LK

I can take a picture of it, if you want, that's no problem.

Yeah I'd like to see this too, very strange, must have had a horrible
picture quality.
Click to expand...

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.547 / Virus Database: 340 - Release Date: 12/2/2003
 
LK sent me a couple photos of this monster. And what a beast it is, too!
Very 70's looking cabinet. I'll forward them your way. I'd actually love
to strip the guts from the cabinet and stick another pullout style lightbox
in there just to get a functional RPTV with that great (tacky) retro look!
The cabinet looks to be in great shape for the age.

-Steve
Click to expand...
LK

The cabinet is in great shape, too bad you're not in New Jersey, I give the
thing to you, if you can get it out the door (It fits in the door way, but it's
heavy as hell)
 
"Steve Reinis" <no-email@all.com> wrote in message
news:bqsu8u01uhm@enews1.newsguy.com...
LK sent me a couple photos of this monster. And what a beast it is, too!
Very 70's looking cabinet. I'll forward them your way. I'd actually love
to strip the guts from the cabinet and stick another pullout style
lightbox
in there just to get a functional RPTV with that great (tacky) retro look!
The cabinet looks to be in great shape for the age.

-Steve
Click to expand...
Yeah that thing is hideous, but interesting at the same time.
 
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