Riddled TV Repair Forum

pensacol · Joined: 02 Jul 2009 Posts: 30

Been working on a RCA 46" rear projection with a convergence problem. Have tried to adjust convergence but it won't adjust right. I made a dvd with a convergence pattern on it to use as a reference cause the built in one just has a little crosshatch in the center of the screen. I am used to the tv's with the STK amplifiers but this one has transistors. Has anybody come across this problem before, or have any suggestions? Also fet U109 on the convergence board is pretty hot to the touch.

Google

kuhurdler · Joined: 28 Dec 2006 Posts: 2879 Location: Overland Park, KS

Is this the 169 with the potentiometers on the front?

There are two different versions of the ctc169 for convergence.

pensacol · Joined: 02 Jul 2009 Posts: 30

yes. this has all of the convergence pots on the convergence board in the front of the tv. i have tried to set it via the pots but it just wopnt come out right.

kuhurdler · Joined: 28 Dec 2006 Posts: 2879 Location: Overland Park, KS

So, what caused the initial change, did this get new CRTs?

pensacol · Joined: 02 Jul 2009 Posts: 30

I got this tv from a friend and he said it got this way over time. When I got it though one of the bolt holes in the plastic housing that holds the mirror in the back had a crack in it and wasn't secure. When the picture would get off he would just adjust the housing until it was right. I have glued the housing back together to the way it should be and bolted it down secure. Could the placement of the mirror being off just a hair mess with the convergence that bad, or just the size of the picture?

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kuhurdler · Joined: 28 Dec 2006 Posts: 2879 Location: Overland Park, KS

Yes, I was afraid that was the case.

I would expect you won't have much success unless you start over with the convergence. You need to follow the procedure given in the service manual. That goes something like this:

First set all the pots on the front to their starting position, and then use the centering rings on the CRT necks themselves. Then you move the pots on the front in the order described. I don't have the manual, or I would give it to you. But have seen it before.

pensacol · Joined: 02 Jul 2009 Posts: 30

That's cool. I have the service manual. So you suspect it's just that, and there's nothing wrong with any of the transistors, by guess?

Jesse Mack · Joined: 22 May 2008 Posts: 600 Location: The Last Frontier

Before you center everything, from the looks of your picture your green, (which is the reference) looks good. Run a string from corner to corner to find the exact center of the screen. Adjust the green centering rings to make the green match the exact center. Now you have a reference. Center pots only for the red and blue and proceed with the convergence. After centering the red and blue pots use the centering rings on the red and blue to match the green (only in the exact center) It looks like the blue and red have horizontal linearity and size missadjustment and adjusting this first (before centering the pots) just might save you a great deal of time.

Hope this helps

Jesse

pensacol · Joined: 02 Jul 2009 Posts: 30

You guys are great. I just wanted to give a big thanks to everybody on here. I will try this tomorrow and see how it goes. My uncle worked for Curtis Mathis and repaired tv's for 30+ years. He was teaching me these things and then he died. I'm getting pretty good at repairing them but some things stump me. I appreciate everything ya'll do here. Keep up the good work.

pensacol · Joined: 02 Jul 2009 Posts: 30

Ok, I've done as you instructed and via the service manual, but some things just won't get right. The top left red is still pincushioned a little to the inside and won't adjust out far enough, and the OSD is halfway off the left hand side of the screen. None of the convergence controls control the osd menu if I'm correct so what could cause this?