CTC169

First off, let me say that I'm not a TV tech.... I'm an elec. eng. who does controls for a living.

Anyhow, I got this dead RCA set for free and am working on it for fun and to learn.

The TV: RCA colortrack 2000 invar CHASIS CTC169

The set was initially dead. After reading through many postings in this group... I have done the following troubleshooting and replaced the following components.

Failed components found:

blown 5A inline fuse Open flame proof resistor 2.5 ohm (if i remember correctly) Shorted B+ regulator

Components replaced: (based on my internet reading)

Above mentioned parts plus....

CR4118 U4101 C4102 C4104 C4108

The set is no longer dead but presents some odd symptoms. The set powers up.... audio is fine. The first thing I see is a horizontal green line across the screen which is shortly replaced by a picture. The picture and menus are darker then they should be and are vertically stretched. If I do an autoprogram (channel search), the picture will return to a normal size, but will remain on the dark side with the menus showing up in dark blue which is barely visible. Once, the set is powered down and back up, the picture is once again vertically stretched and cured by autoprogram.

I've measured the cathode voltages of CR4118 & CR4116 to the ground around the picture tube. The voltage readings are 12.47 and 135 respectively Based on my reading, these sound a bit low, but I'm not sure where to go from here. I have followed the ground path around the board and cleaned up some solder joints, but the symptoms persist. Any thoughts?

Thanks Bob

Bob, I have even less qualifications than you to open up a TV set, but I just finished fixing the remote receiving unit on a 1987 Mitsubishi set. In the course of the repair I discovered two switches on the printed circuit board mounted on the end of the cathode ray tube. They are both three-position switches and while manipulating the main circuit board with all its wiring I managed to move one of them to the wrong position.

I ended up with a single horizontal line across the middle of the tube. After resetting it and getting back the whole picture, I flipped them both all three ways to see what happens. The color changed as if the blue or red had been lost. So I flipped them back to where everything was good. This may or may not have anything to do with your problem, but you may find this site helpful. It's where I learned about those switches and where they are located:

Sci.Electronics.Repair FAQ: Main Table of Contents

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Scroll down to where it reads:

Television Sets (new segmented, includes download link) | (latest whole

- slow)

Lots of great troubleshooting info there.

Good luck, Jack