Hello,
I am now facing the problem of my old RCA television set not being able to produce a picture. i have replaced tubes and a few condensers. It brings strong sound, but no picture. If anyone is able to tell me what might be wrong with this, i would be extremely grateful.
Thank You

Replace following:
Rest of paper caps.
All electrolytics.
Selenium rectifiers.
Off value resistors.
Add some resistance to your new 4007 silicons on the ac side. They have less resistance than the seleniums did, so, voltages will be higher.
These sets are also prone to poor connections on circuit boards.
Have you tested the crt on a crt tester to make sure it is good?
Bill Cahill

If you turn up the brightness control do you get light on the screen of the picture tube? This is called a raster. If not, I would check the high voltage and horiz section. If you do, I would check the video section. Common problem with no raster is bad horizontal output tube or bad HV rectifier. However let us know about raster and folks here can walk you through repair. Jim

You just received two responses each having a different theory as to handling these old TV sets. I am of the school of thought that I like to find the problem and fix that problem and then do any preventive work. You have turned the set on or you would not know that it has sound. I say this because many folks do not turn the set on until they replace some parts. I can not take issue with this approach, but since you have had it on, I would fix the problem before replacing parts for preventive work. This way you have a working set before replacing a great number of parts. If you make a mistake in your preventive work you will immediately find it. If you start replacing many parts of a non working set you run the risk of incorrectly installing a part and making a set with multiple problems and making the repair much more difficult. Now having said that, note that it is my opinion and others have a different opinion. I expect to recieve some hostile e-mail. It is your set and you will have to decide how you want to fix it. Jim

This will require some methodical diagnosis to determine why you don't have a picture or raster on screen.

The first step would be to determine if the set is producing High Voltage to the CRT.

The easiest check for this is to hold the blade of an insulated screwdriver next to the cap of the HV rectifier tube (probably a 1B3 or an 1X2 in this case) you should be able to draw a healthy blue arc to the blade of the screwdriver, if you can't in indicates a problem in the HV system, very possibly an inoperative Horizontal Oscillator.

If you do get High Voltage but nothing on the screen then you need to see if the Ion trap on the neck of the CRT is adjusted correctly. This is a small magnet assembly on the neck of the tube between the Yoke and the Base.

Do not replace everything first and hope it works, as noted you can cause yourself no end of headaches doing that.

Find out why you don't get a picture and concentrate on that first, i.e. no High Voltage, work on that section first.

Thank you for your input. No, no picture whatsoever or any light projects on the screen. i will get to replacing the other necessary parts. I do not usually turn on old things without replacement, but i had been told it was reconditioned and it worked.

Is the horizontal oscillator running? Can you hear the high pitched noise from the Horizontal output transformer? Be careful in there, it is a very high voltage area and if you don't know what you are doing you can get in a world of hurt fast. Jim

The ability to hear the high pitched noise from the Horizontal output transformer depends on how old you are and how much very loud music you have listened to. The frequency involved is 15700 HZ. Kids can hear frequencies a little beyond 20000 HZ. Old people may not be able to hear even 10000 HZ.

Holding a well insulated screw driver blade near the cap of the high voltage rectifier and checking for an arc will tell you if the horizontal oscillator and horizontal output stages are working. You can still fail to have high voltage at the CRT if the high voltage rectifier tube is bad.

I agree with diagnosis 1st. If it was working and then not, then it may be a single problem. By replacing stuff you add the possible new problem.

1st thing to do is determine if there is HV at the anode. do that then check back for more help. It seems pointless to try and give you step by step advise without knowing the results of a basic test. Testing for HV at the anode will prevent a TON of maybe this maybe that answers.

Back to basics. If you put a neon bulb near the horizontal output, it should glow if the set is mostly working. CRAIG