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RCA ColorTrak FMR620WR (CTC-130A) From 1986
This 25" tabletop set used to be my grandparents basement TV:
http://s30.postimg.org/3yiwuu8ct/Overview_2.jpg It's seen a lot of use over the years and attracted quite a bit of dust: http://s8.postimg.org/90om4v4td/Dusty_Caution_Tag.jpghttp://s30.postimg.org/5l84g2kel/Dusty_Yoke.jpg The flyback anode is shoddily zip tied to various yoke & neck board wires, leading to arcing: http://s2.postimg.org/mbn8mnpl1/Anode_Wrap.jpg I've since spread the wires apart by using a paint stick. This reduces the arcing noise. On the main board, R506 & (to a lesser extent) R417 had charred solder joints: http://s15.postimg.org/ba9aek54n/R506.jpg I presume that this is due to the solder pad/trace being too small. I made sure to resolder/reinforce them. -- As for other issues with this set: 1.) The top left corner convergence magnet was broken off and is missing (likely from a previous "servicing"). 2.) The convergence is off in general. I presume the adjustment magnets are under the zip tie on the CRT neck. Can anyone confirm? 3.) The picture is shifted down and to the right. There are no centering potentiometers on this chassis. Has anyone installed their own? 4.) Stereo speakers without stereo circuitry. Does anyone have the schematic and/or the theory of operation for the stereo adapter? |
This set may have a bonded yoke. In other words factory
adjusted for purity, tilt & convergence then glued in place. See if its loose. Normally this set can not get out of convergence. If its not bonded they sold a magnet kit to replace the magnetic tape on the neck if the CRT was changed. Not sure what magnet is missing. ?? Arcing is strange. I cant think of an set after abt 1980 that arced at the wire. Just a few at the connector. Centering could be done with taps but again would not change without a failure. Stereo decoders take the IF from the tuner & its basicly a radio added. put up some screen shots that will help. Do some with NO color & some with. Also normal pix & a pattern. |
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You can lay a clean 2nd anode lead against anything without arcing - 40KV wire doesn't arc - the dust is providing a second path for the HV. |
The V magnets are correction magnets. They are over the area
where the purity is off after the set-up. You can use any small magnet, a refrigerator door gasket magnet works fine. But for convergence on the sides you bend the yoke then jamb a wedge in place. For now its best NOT to mess with it til you can put up a pattern & screen shots. Could be other things like the CRT. For now bring it outside & blow the dust out. Remove the HV lead & clean everything along the wire & the uncoated glass around the anode button with 91% isopropal alcohol. Let dry then try it. 73 Zeno:smoke: |
The wisdom and knowledge on this site never ceases to amaze me.
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Here's the best I can do for photos:
The worst of the convergence is at the top right side (where the v magnet is missing): http://s29.postimg.org/wuu19icib/Top...onvergence.jpg Some full shots from my 16:9 calibration disc (excuse the interference): http://s29.postimg.org/y27z1q2mr/Calibration_Menu.jpghttp://s7.postimg.org/r7ja0cy07/Monochrome_Bars.jpghttp://s9.postimg.org/tfhk3hd9n/Red.jpghttp://s12.postimg.org/xvjokpzbd/Green.jpghttp://s13.postimg.org/4o0ryilzn/Blue.jpg Other A/V sources: http://s1.postimg.org/87uh2mvln/get_TV_Monochrome.jpghttp://s9.postimg.org/ydi3lay5n/LD_Turtle.jpg |
Unfortunately, your image host has a pop up that requires a download, so I'm not going there...
Flickr, photobucket and imgur are better, and don't badger folks with popups that starts a download of unneeded junk. |
^That's not a pop-up, it's a banner. The photo is at the center of the page. If you can't stand those banners, an app like this one will remove them.
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I run AdBlockPlus already. |
^Then why am I not receiving any pop-ups? I trust you're running Windows.
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OK the conv is off in the center & you wont get the sides
right without the center. CRT looks strong, grey scale off a little try a little green. So why is it off ? May have always been like that ? Another theory is the neck magnet has changed by sitting in the same place for 30yrs by the earths field. If it were me I would mark the magnet so you can put it back then cut the tie and try adjusting it. Without a set of rings thats about all you can do. 73 Zeno:smoke: |
Found the RCA part number for magnets.
36157300008 this is not the usual 6 digit format so it may be a drawing number. 73 Zeno:smoke: |
After creating a 4:3 test pattern DVD from here, I proceeded to make adjustments.
I did not cut the zip tie from the convergence magnet. It was loose enough to slide off and proved useful for clamping down the magnet after the packaging tape was removed. The static convergence was not originally calibrated. Instead, they chose to generically set the seam of the magnet to the 12 o'clock position on the yoke assembly, probably to speed up the assembly process. I found it looked best between the 7 & 8 o'clock positions: http://i.imgur.com/2UPckVOt.jpg ^The upper right corner is still bad. No amount of yoke adjustment would improve it. I'll need to make a v magnet at the very least. Then, I adjusted the green bias: http://i.imgur.com/3SkQO4Bt.jpg Note the powdery blue distortion at the upper left on the white and yellow, it's not dust and it's not on the outside of the CRT: http://i.imgur.com/oanzkr3t.jpg While the static convergence adjustment did greatly improve the horizontal centering, the vertical centering is still off: http://i.imgur.com/U8bpw41t.jpg ^The yoke doesn't go up any further. It needs to be adjusted electronically with modification. I just need to know where to install a variable resistor, as well as its' ohm range and any supplementary components. |
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