Lines in toshiba crt tv

[ENERGYSAVINGS]

MODEL 20AF41
MFG DATE 2001 CRT TV

I need opinions, info here.
What to suspect, old CRT or worn caps? Ive heard electrolytics in the vertical circuit could do this.
Thoughts all?

[ENERGYSAVINGS]

Re: Lines in toshiba crt tv

By the way, I have no schematic for this TV.
But I am equipped with a full line-up of test equipment, except a capacitor tester, as I have never seen one that can reliably test caps in or out of circuit, even expensive ones.
I test for ripple under load with an O-scope, provided the unit functions as this one does.
Thanks in advance!
-Lemur

[budm]

Re: Lines in toshiba crt tv

Service manuals:
http://elektrotanya.com/?q=showresul...oria=&kat2=all

So only seeing just one vertical line?

[stj]

Re: Lines in toshiba crt tv

foto's of the problem please.
and it's not the crt - they last and last.
unilike modern crap, a crt that does not use a narrow neck can last 30years+

[ENERGYSAVINGS]

Re: Lines in toshiba crt tv

I took a photo and forgot to attach it. Here it is.

[tom66]

Re: Lines in toshiba crt tv

To me, looks like it is not blanking the signal properly on the vertical retrace. I know bad capacitors are common with many older Toshiba CRTs due to the use of Capxon capacitors.

[ENERGYSAVINGS]

Re: Lines in toshiba crt tv

The picture looks bad because the shutter speed was too fast, the actual picture on the TV is good except for the lines at the top of the screen, at its worst, there is actually some "wrap around", or "foldover" your choice, at the top.

[stj]

Re: Lines in toshiba crt tv

probably small caps in the vertical timing area.

does the picture look shifted down if you use teletext?
because it could be your seeing the "hidden" lines used for teletext/closed-caption data.

[Th3_uN1Qu3]

Re: Lines in toshiba crt tv

Replace C436, C407, C406. As seen on the schematic, page titled "Deflection schematic diagram". Should work fine then. Of course, also check for other bulged caps while you're in there. Those mentioned are too small to bulge, they would have simply dried out.

[stj]

Re: Lines in toshiba crt tv

and check for broken solder joints on all transformers and parts bolted to heatsinks.
broken soldering was common on crt tv's

[ENERGYSAVINGS]

Re: Lines in toshiba crt tv

By small caps, do you mean not electrolytics?
I don't have the time to reverse engineer the TV, so it looks like I'm going to be shotgunning alot of caps. I haven't had to deal with this problem before, and could use a little direction of what area to shotgun, if some else has the experience/ knowledge.
By the way, I tried the text mode, it seems to make no difference.


But Hey!
THANK YOU guys for the schematic link and the other help, I am grateful.
By the way, I tried the text mode, it seems to make no difference.

[ENERGYSAVINGS]

Re: Lines in toshiba crt tv

Th3_uN1Qu3,
Didn't see your response before my last post, seems you answered my question.
Thank you.