1981 Magnavox with a problem.

[miniman82]

There have been multiple suggestions that you obtain a schematic, i suggest you heed that advice before taking any more stabs in the dark. You're only likely to cause self-induced faults by shotgunning parts into it, and I doubt there's anything wrong with the flyback if you still have high voltage.

[Firebird]

No its the sound and color.

[miniman82]

Go to Sams website, order the schematic if they have it.

[holmesuser01]

See post #58.

My final reply on this.

[Firebird]

Can anyone tell me what component would cause this set to have a near perfect black and white picture. No color, no sound. Picture does streach about a half an inch to the right. Tuner seems to work perfect on basic cable and of course there is no analog broadcast tv anymore. If you can help you will be a hero. TV has not played regularly since 1986 when it died right in the middle of a Joan Rivers joke. Of course i knew nothing about tv repair back then.

[mpatoray]

No we can not GUESS at what component may have failed. You need a schematic to troubleshoot. I know you have been told that many times but for some reason you do not want to listen. Heck if you don't want to BUY a Sam's for the set some good public libraries have collections, find it and make a Xerox!

[Firebird]

Where i live in rural NC?

[holmesuser01]

I live in rural NC, and have no problems getting schematics for things I want. Dont blame NC for your problems.

[sampson159]

the techs here in this board will point you in the right direction but you have to perform the actual work.get a schematic and get busy.we will help you along the way but start with a schematic.ask for one here and you will get one.i wish you the best of luck on this set.pretty decent models with a fine picture when right.

[dieseljeep]

Originally Posted by sampson159

the techs here in this board will point you in the right direction but you have to perform the actual work.get a schematic and get busy.we will help you along the way but start with a schematic.ask for one here and you will get one.i wish you the best of luck on this set.pretty decent models with a fine picture when right.

I don't remember if that set is a modular set. The set came out around the time I quit repairing, on a regular basis.

[Jeffhs]

I agree with Sampson159 as to finding a schematic for anything you attempt to service or repair, be it a TV, radio or anything else electronic, before troubleshooting; "blind" attempts at finding trouble in a set often cause more problems than are solved.

My only other advice, however, is to be cautious around the CRT, as it has a very high voltage (in the double digit kilovolt range) -- the second anode voltage -- on it that can be lethal or can cause serious injury if you don't take the appropriate precautions. In color sets like your Maggie, the normal HV will be around 25kV or so; in a b&w set, it is a bit lower, around 18kV or thereabouts, but still, nothing to take lightly. And whatever you do, do not work on a TV or radio while the unit is still under power (plugged in to the AC line). Pull the plug and discharge the CRT in a TV before doing anything inside the cabinet. To discharge the tube, simply slide a metal screwdriver under the cap covering the high-voltage lead coming from the flyback. Remember that the HV charge on a CRT can remain on the tube for quite a while after the set is turned off, even if it has been unplugged and unused for years.

[jr_tech]

Originally Posted by Jeffhs

To discharge the tube, simply slide a metal screwdriver under the cap covering the high-voltage lead coming from the flyback. Remember that the HV charge on a CRT can remain on the tube for quite a while after the set is turned off, even if it has been unplugged and unused for years.

Hopefully that is a GROUNDED screwdriver!

jr

[Jeffhs]

Originally Posted by jr_tech

Hopefully that is a GROUNDED screwdriver!

jr

I stand corrected. Yes, a grounded screwdriver should be used to discharge the residual HV charge on a CRT; I've been in electronics (as a hobby) and in ham radio 40 years, and should know that.

This is a good warning for newcomers to tube TV repair, however, as folks who have only known solid-state and, particularly (since the mid-'80s) flat-screen TVs may not be aware of the dangers of the redsidual charge on the CRT bell on old analog NTSC TVs -- even after the set has been unused for some time. The aquadag coating on the CRT bell acts as a huge capacitor and can hold a charge for a very long time, so discharging the tube by using a grounded screwdriver slid under the second anode cap until it contacts the terminal which connects to the 2nd anode well on the side of the tube is a must, before any work is begun on the chassis. (I would discharge the CRT even before changing tubes, as some older TVs had some tubes located near or directly under the CRT bell; I've owned a few -- my Philco Microgrid 390 23" console, now long gone, of course, comes to mind.)

Again, the voltage coming from the flyback in all CRT televisions is extremely high (20kV+ in color sets) and can cause serious injury or even death, so be careful. The voltage on LCD or plasma panels in today's flat TVs is nowhere near that high (several hundred volts at most), but, nevertheless, caution should be used around them as the potential for serious injury still exists.

[holmesuser01]

Originally Posted by dieseljeep

I don't remember if that set is a modular set. The set came out around the time I quit repairing, on a regular basis.

Its got several modules. Other than the mentioned parts earlier, I rarely had one on my bench that had other problems. I worked on them from 1981-on.

I threw out a good T-815 chassis that had been sitting in my old shop for 10 years. Kept it because it worked, and the CRT went to air. Intended to use it, but never had another one to work on.

[Firebird]

Does anyone have a T815 schematic?