GE TV w/ CTC195 Chassis: Sound but no picture


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GE TV w/ CTC195 Chassis: Sound but no picture

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edominguez
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Aug 3, 2005, 2:48 PM

Post #1 of 13 (3882 views)
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GE TV w/ CTC195 Chassis: Sound but no picture	Can't Post

Greetings! Last night I replaced the flyback transformer in my GE TV, all thanks to this forum and everyone who wrote about this particular issue... thank you! The initial symptoms, before flyback xfrmr replacement, were no apparent power, no sound & no picture, only ticking / chirping sound and occasional arcing. Anyway, the TV now turns on, there is sound but there is no picture. The TV appears to function correctly with respect to raising / lowering volume, changing channels, etc. (all via DVD player & satellite recvr as well) I've checked the 2 wires connected to flyback xfrmr and confirmed that they are secure. Does anyone have any suggestions regarding my problem? I read a few posts regarding silimar symptoms related to bad HV splitters and horizontal output transistors. Could these components also be culprits to my "there is sound but there is no picture" dilemma? Any suggestions, and, or, comments would be greatly helpful.

Best Regards,

E Dominguez

kuhurdler
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Aug 3, 2005, 3:11 PM

Post #2 of 13 (3871 views)
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Re: [edominguez] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

I would definately check the HOT first.

-RiddledTV.com
http://www.riddledtv.com/forums/

mel
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Aug 3, 2005, 10:23 PM

Post #3 of 13 (3862 views)
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Re: [edominguez] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

Have you tried turning up the screen voltage?

shadetree
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Aug 4, 2005, 2:00 AM

Post #4 of 13 (3859 views)
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Re: [edominguez] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

make sure all the pins on the flyback are well soldered

edominguez
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Aug 4, 2005, 3:12 PM

Post #5 of 13 (3850 views)
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Re: [shadetree] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

All,

I am acknowledging all suggestions and advice:

Kuhurdler, I may have jumped the gun as I ordered an H/O transformer yesterday for $10 & some change. Unfortunately, I do not have a very strong skillset of component level troubleshooting / repair as it is not my profession. But I do have basic knowledge of electronics theory to perform various tasks, i.e., measuring voltage, current & resistance, soldering, etc. Is there a particular procedure to confirm that the existing HOT is good or bad, and if so will you enlighten me as to how to perform the test?

Mel, I have not tried your suggestion but I am willing to do so. I'm curious, is it possible that certain adjustments may be needed after installing a somewhat major component as the flyback transformer? Please advise on how to turn up the screen voltage and I will attempt the procedure today.

Shadetree, I reviewed the soldered pins and they all appear to be good; nice and shiny joints. I also made sure that I did not burnoff or otherwise damage any of the pads on the ckt board.

kuhurdler
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Aug 4, 2005, 3:17 PM

Post #6 of 13 (3846 views)
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Re: [edominguez] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

I'm with Mel. Make sure you adjust the screen knob on the flyback that you already installed.

To check the horiz output TRANSISTOR, I just connect it to a transistor tester (a $20 radioshack tester). I know you can also do it with a cheap multimeter, but I couldn't tell you how without actually doing it.

-RiddledTV.com
http://www.riddledtv.com/forums/

shadetree
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Aug 4, 2005, 4:20 PM

Post #7 of 13 (3838 views)
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Re: [edominguez] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

did you use an rca-ge replacement flyback or a generic part ? generics don't always work right

edominguez
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Aug 4, 2005, 6:02 PM

Post #8 of 13 (3834 views)
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Re: [shadetree] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

Good question. The part is actually an RCA replacement flyback xfrmr, or atleast that's what was conveyed on the box and installation instructions that the part came in / with. I'm also a bit confused now because I don't recall seeing any type of voltage adjustment on the old xfrmr or the new xfrmr. If I recall correctily Mel & Kuhurdler earlier suggested adjusting the "screen voltage" knob located on the flyback xfrmr. Is there perhaps a screen voltage adjustment elsewhere?

mel
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Aug 4, 2005, 10:22 PM

Post #9 of 13 (3829 views)
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Re: [edominguez] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

If the replacement did not come in an RCA box with an RCA part number on it, It is probably not an RCA part but a generic. There are two knobs on the back of the flyback. One is the focus and the other the screen voltage adjust. Both will need to be adjusted. Just turn the screen voltage up untill you see retrace lines and then back it off until they just disappear. You can test the HOT with a VOM by checking the resistance between the collector and base and collector and emitter and then reverse the leads. You should get a higher resistance in one direction that the other. Unsolder the base and/or emitter and do the same test there.

edominguez
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Aug 5, 2005, 3:27 PM

Post #10 of 13 (3820 views)
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Re: [mel] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

Mel, thanks for the insight (good stuff). I will attempt adjustments as you suggested, although I'm almost sure I did not see any adjustment knobs on the flyback xfrmr. I am also going to test the HOT using a V/O meter as you prescribed. It appears that I have my work "cut out" for me this weekend. I will update everyone on my progress / findings early next week. Again, thanks, Mel, and everyone else for your assistance!

shadetree
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Aug 5, 2005, 4:10 PM

Post #11 of 13 (3816 views)
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Re: [edominguez] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

is that a projection tv if so ck hi voltage divider must be if there are no controls on flyback

edominguez
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Aug 5, 2005, 6:43 PM

Post #12 of 13 (3813 views)
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Re: [shadetree] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

Shadetree, it is a projection TV. I've been pondering, intensely, how I could have missed any kind of adjustments on the flyback xfrmr. I am glad you were observing the latest posts on this issue! Where might I find the high voltage divider within the unit, and, is re-adjusting the voltage a common procedure after replacing the flyback xfrmr, or any other related component?

shadetree
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Aug 6, 2005, 5:53 PM

Post #13 of 13 (3803 views)
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Re: [edominguez] GE TV w/ CTC195 Chassis: Sound but no picture [In reply to]	Can't Post

you won't have to adjust voltage follow red lead out of flyback to divider

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