[TechAssist] Re: CTC203 won't start and click
- From: "teltek3" <teltek3@xxxxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Thu, 23 Jan 2003 08:06:58 -0500
Accidentally is the key word. Since the yoke is an integral part of the
Horiz/Vert circuit, not very much can be proven by disconecting the yoke,
sort of like taking your car arond the block with the wheels off, because
you have a noise from the differential. Output transistors were meant to be
run with a load applied, and burns on the CRT don't take very much time,
with High Voltage applied.
-Ed-
Tel-Tek Electronics
Ontario-Canada
teltek2@xxxxxxxxxxxx
----- Original Message -----
From: "Gary McCartney" <gary@xxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Thursday, January 23, 2003 1:20 AM
Subject: [TechAssist] Re: CTC203 won't start and click
>
> The only time I accidently ran a set without the yoke connected, it
> burnt a spot in the center of the screen in about 5 seconds. Before I
> noticed it and reached for the cord, it was too late.
>
>
>
>
> Gary McCartney
>
> McCartney Electronics
> 7134 Fife Rd, RR 7
> Guelph Ontario Canada N1H 6J4
> Fax: (519)821-1530
> email: gary (at) number63.ca
>
>
>
>
>
>
> Jeff Dougherty wrote:
> >
> > Al,
> > Yes it would..the brighter the DOT...the quicker it would burn.
> > support@xxxxxxxxxxxxxxxxxx
> > FAX 717-564-4952
> > Jeff Dougherty
> > Intrepid Video & Electronics Be careful of your thoughts.
> > 501 Luther Rd They may become your words
> > Harrisburg, PA 17111 any moment.
> > 717-909-8844
> > VCR tips, electronics info & general interest.
> > www.intrepid-video.com www.tech-repair.net
> > www.thetoolcaddy.com www.9-11-2001tragedy.com
> > ***********************************************************************
> >
> > ----- Original Message -----
> > From: "al m" <ampm@xxxxxxx>
> > To: <techassist@xxxxxxxxxxxxx>
> > Sent: Tuesday, January 21, 2003 9:18 PM
> > Subject: [TechAssist] Re: CTC203 won't start and click
> >
> > Now this might seem like a stupid question but would turning down the
screen
> > voltage stop the burning of the CRT?
> > al marquardt
> > ampm@xxxxxxx
> >
> > ----- Original Message -----
> > From: "Jeff Dougherty" <support@xxxxxxxxxxxxxxxxxx>
> > To: <techassist@xxxxxxxxxxxxx>
> > Sent: Tuesday, January 21, 2003 4:24 PM
> > Subject: [TechAssist] Re: CTC203 won't start and click
> >
> > >
> > > Yes, I have seen it in 90 sets, at least.
> > > I never left it on long enough to burn the phosphors.
> > > support@xxxxxxxxxxxxxxxxxx
> > > FAX 717-564-4952
> > > Jeff Dougherty
> > > Intrepid Video & Electronics Be careful of your thoughts.
> > > 501 Luther Rd They may become your words
> > > Harrisburg, PA 17111 any moment.
> > > 717-909-8844
> > > VCR tips, electronics info & general interest.
> > > www.intrepid-video.com www.tech-repair.net
> > > www.thetoolcaddy.com www.9-11-2001tragedy.com
> > >
***********************************************************************
> > >
> > > ----- Original Message -----
> > > From: "Bil Green" <tv.vcrrepair@xxxxxxxxxxx>
> > > To: "Joe Batchelor" <techassist@xxxxxxxxxxxxx>
> > > Sent: Monday, January 20, 2003 8:21 AM
> > > Subject: [TechAssist] Re: CTC203 won't start and click
> > >
> > >
> > >
> > > I have been pulling the yoke plug on direct view TVs on ocassion for
> > > many years and don't recall seeing a bright dot on sets made in the
> > > 1980 or 90s. Have you seen this?
> > >
> > > When talking to tech support I have not been critised for doing this.
> > > At one point GE recommended this proceedure to limit the HV and
> > > reduce the chance of blowing a HOT while testing.
> > >
> > > In the 1960s and 70s this was definately a no-no.
> > >
> > >
> > > --
> > > Best regards,
> > >
> > > Bil Green
> > > 2001 TV VCR
> > > Mammoth Lakes, California
> > > 760-934-2001 mailto:tv.vcrrepair@xxxxxxxxxxx
> > >
> > >
> > > Sunday, January 19, 2003, 2:58:00 PM, you wote:
> > >
> > >
> > > >>One of the first things to do is simply pull the yoke plug . . . .
> > >
> > > JB> I would never tell anyone to do this.
> > > JB> It could burn a spot on the CRT if high voltage does come up.
> > >
> > > JB> In the good old days they had a jumper or interlock that would
> > > JB> break the B+ when the yoke was unplugged.
> > >
> > > JB> I would remove the CRT socket before trying to run a set without
> > > JB> the yoke plugged in.
> > >
> > > JB> Joe Batchelor CET TX-80
> > >
> > > JB> 1/13/03 10:44:42 AM, Bil Green <tv.vcrrepair@xxxxxxxxxxx> wrote:
> > > >>Hi Pete,
> > > >>
> > > >>If you have way too much current flowing through the flyback then
the
> > > >>problem should be in the collector circuit of the HOT (including the
> > > >>flyback of course). I don't see how the Gemstar module could cause
too
> > > >>much current in the collector circuit of the HOT unless the horiz
freq
> > > >>is way off.
> > > >>
> > > >>One of the first things to do is simply pull the yoke plug (much
easier
> > > >>than changing the yoke or troubleshooting the whole circuit).
> > > >>
> > > >>With the yoke out of the circuit the HV will be much lower than
normal
> > > >>(may even work if the yoke circuit was the problem).
> > > >>
> > > >>Good to scope the collector of the HOT also. Make sure your scope
can
> > > >>handle at least 200VAC and always set the 10x probe to 10X or the
> > > >>~1500 or so volts will fry your scope. With the 100W lamp in series
> > > >>with the ~130V B+ you may get a reading on the collector. Somewhere
> > > >>around 1000VPP (without the light bulb), very clean pulses, about
12us
> > > >>wide, ~55us between pulses.
> > > >>
> > > >>You replaced the flyback, yoke, etc? I almost always check to see
> > > >>which parts are actually bad first. Whenever I guess, I'm almost
always
> > > >>wrong. Expensive to replace a few large parts. Pull the yoke, ring
> > > >>test the flyback (or eliminate other possibilities first).
> > > >>
> > > >>You may want to put the original symptom back into this e-mail so
> > > >>people know what the problem is. I forgot what you said.
> > > >>
> > > >>--
> > > >>Best regards,
> > > >>
> > > >>Bil Green
> > > >>2001 TV VCR
> > > >>Mammoth Lakes, California
> > > >>760-934-2001
mailto:tv.vcrrepair@xxxxxxxxxxx
> > > >>
> > > >>
> > > >>Saturday, January 18, 2003, 5:53:06 AM, you wote:
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>P> Thanks Bil, that's what I get, to much current and no any raster,
and
> > as
> > > >>P> I wrote in my first post, I've replaced all those parts in the
output
> > > >>P> circuit. scoping the base drive signal on the HOT, seems to be on
> > > >>P> frequency and value.
> > > >>
> > > >>P> Well..... this is an RCA 203 model chassis...
> > > >>P> Do you think that the "GEmstar" module
> > > >>P> could be the problem??
> > > >>
> > > >>
> > > >>P> E-mail message
> > > >>
> > > >>P> Sender: techassist-bounce@xxxxxxxxxxxxx From:
> > tv.vcrrepair@xxxxxxxxxxx
> > > >>P> (Bil=A0Green) Date: Wed, Jan 15, 2003, 4:19am (EST-3) To:
> > > >>P> techassist@xxxxxxxxxxxxx (Pete)
> > > >>P> Subject: [TechAssist] Re: CTC203 won't start and click
Reply=A0to:
> > > >>P> techassist@xxxxxxxxxxxxx
> > > >>
> > > >>P> Hi Pete,
> > > >>P> When using a 100W lamp in series with the B+ to the flyback, it
> > should
> > > >>P> not light up brightly. If it does you have too much current
flowing.
> > > >>P> If everything is OK you will get a raster (smaller than normal,
but
> > good
> > > >>P> enough to show that the all the circuits are working).
> > > >>
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> > >
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> --
>
>
>
>
> Gary McCartney
>
> McCartney Electronics
> 7134 Fife Rd, RR 7
> Guelph Ontario Canada N1H 6J4
> Fax: (519)821-1530
> email: gary (at) number63.ca
>
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