Vertical Lines
in [Repair]
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From: DB on 23 Jun 2010 10:42 "DB" <x(a)x.com> wrote in message news:vLmdnX7vEcXgzbzRnZ2dnUVZ_qCdnZ2d(a)earthlink.com... > > "DB" <x(a)x.com> wrote in message > news:deadnRItKurh1rzRnZ2dnUVZ_rCdnZ2d(a)earthlink.com... >> Have a Toshiba 30HF85 30" TV. There are vertical lines at the top of the >> screen. I believe I need to replace the cap near the vertical hold IC. >> Where is the vertical hold IC? Thanks. >> > > Mistake!! I have horizontal lines near top of screen!! Sorry. > I believe it's called vertical fold over. I most likely need to replace a bad cap near the vertical hold IC. Which takes me back to my original question: Where is the vertical hold IC? What's the shape and how many pins? Thanks.
From: DB on 23 Jun 2010 10:44 "Meat Plow" <mhywatt(a)yahoo.com> wrote in message news:pan.2010.06.23.14.32.45(a)gmail.com... > On Wed, 23 Jun 2010 10:18:24 -0400, DB ??o??: > > >> "DB" <x(a)x.com> wrote in message >> news:vLmdnX7vEcXgzbzRnZ2dnUVZ_qCdnZ2d(a)earthlink.com... >>> >>> "DB" <x(a)x.com> wrote in message >>> news:deadnRItKurh1rzRnZ2dnUVZ_rCdnZ2d(a)earthlink.com... >>>> Have a Toshiba 30HF85 30" TV. There are vertical lines at the top of >>>> the screen. I believe I need to replace the cap near the vertical >>>> hold IC. Where is the vertical hold IC? Thanks. >>>> >>>> >>> Mistake!! I have horizontal lines near top of screen!! Sorry. >>> >>> >> Listen guys. I have a 2 year degree in elect/electronics. > > I have a 35 year degree in experience on the job. The structure of your > questions are a dead giveaway (no pun intended) that you should not be > inside the back of a set relying on your associates degree to protect you. > That is unless you wrap it around your hand as an insulator. I've already been in there. You're not responsible. Which IC is it? Thanks.
From: stratus46 on 23 Jun 2010 11:16 On Jun 23, 7:44 am, "DB" <x...(a)x.com> wrote: > "Meat Plow" <mhyw...(a)yahoo.com> wrote in message > > news:pan.2010.06.23.14.32.45(a)gmail.com... > > > > > > > On Wed, 23 Jun 2010 10:18:24 -0400, DB ??o??: > > >> "DB" <x...(a)x.com> wrote in message > >>news:vLmdnX7vEcXgzbzRnZ2dnUVZ_qCdnZ2d(a)earthlink.com... > > >>> "DB" <x...(a)x.com> wrote in message > >>>news:deadnRItKurh1rzRnZ2dnUVZ_rCdnZ2d(a)earthlink.com... > >>>> Have a Toshiba 30HF85 30" TV. There are vertical lines at the top of > >>>> the screen. I believe I need to replace the cap near the vertical > >>>> hold IC. Where is the vertical hold IC? Thanks. > > >>> Mistake!! I have horizontal lines near top of screen!! Sorry. > > >> Listen guys. I have a 2 year degree in elect/electronics. > > > I have a 35 year degree in experience on the job. The structure of your > > questions are a dead giveaway (no pun intended) that you should not be > > inside the back of a set relying on your associates degree to protect you. > > That is unless you wrap it around your hand as an insulator. > > I've already been in there. You're not responsible. Which IC is it? > Thanks. Then buy the service manual. G²
From: Stefan Heimers on 23 Jun 2010 11:15 DB wrote: > Which takes me back to my original question: Where is the vertical hold > IC? > What's the shape and how many pins? Thanks. There are two coils on the back of the CRT. The horizontal is connected to the horizontal output transformer (which is also the high voltage transformer, I'm sure you recognize it). Now just track the connection to the other coil. This comes from the vertical output stage, which is driven by the vertical sync circuit. If your picture is stable besides of the wrong size, its probably not the vertical IC at fault, but the power amplifier after it, or the power supply. If there are only a few lines, and they are crossing the picture diagonally, then it's the beam which is not blanked during the vertical flyback. This can be caused by a worn out picture tube, or by the grid bias voltages. I don't know about your TV, but usually there are some potentiometers for adjusting the grid voltages and slightly changing it makes the lines diasppear. That's what it lools like: http://bs.cyty.com/menschen/e-etzold/archiv/TV/uvb/img/MC47_ohneUVB.jpg Is yours similar to that? Stefan
From: DB on 23 Jun 2010 11:30
"Stefan Heimers" <stefan.usenet(a)heimers.ch> wrote in message news:hvt8ke$rqb$1(a)news.albasani.net... > DB wrote: > > >> Which takes me back to my original question: Where is the vertical hold >> IC? >> What's the shape and how many pins? Thanks. > > > There are two coils on the back of the CRT. The horizontal is connected to > the horizontal output transformer (which is also the high voltage > transformer, I'm sure you recognize it). > > Now just track the connection to the other coil. This comes from the > vertical output stage, which is driven by the vertical sync circuit. > > If your picture is stable besides of the wrong size, its probably not the > vertical IC at fault, but the power amplifier after it, or the power > supply. > > If there are only a few lines, and they are crossing the picture > diagonally, > then it's the beam which is not blanked during the vertical flyback. This > can be caused by a worn out picture tube, or by the grid bias voltages. I > don't know about your TV, but usually there are some potentiometers for > adjusting the grid voltages and slightly changing it makes the lines > diasppear. That's what it lools like: > > http://bs.cyty.com/menschen/e-etzold/archiv/TV/uvb/img/MC47_ohneUVB.jpg > > Is yours similar to that? > > Stefan > > Thanks. Finally some useful info. The symptoms look more like when the picture is adjusted to large and it folds back, to where you can see and image in the lines, but upside down. Only about 1" at the top. |