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General Electric 19PF6756
One of our neighbors put a GE 19PF6756 out on the curb with the free sign so I picked it up because it looks like it was made in the USA in Portsmouth Virginia. The CRT seems good for being around 29 years old.
There are lines going from top to bottom on the left side and people and objects have halos around them. I’m sure replacing almost all the electrolytic capacitors can improve the picture a lot, but I am worried about the flyback. The flyback makes a lot of little popping noises when I turn on the TV but after letting it run for around a half an hour to an hour the noise seems to disappear. See and hear video: https://www.youtube.com/watch?v=U4zj...zwGrSUp7Ee8uvA Are there any capacitors I should replace before using the TV anymore? Is my hearing too good with worrying about the flyback? |
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Gotta be one of the last real GEs made. Nice set!
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Looks nice from what I can see. How about a wide shot of the whole set?
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Looks like a "PC" chassis set. There's a 100 uf cap in the vertical circuit (near the vertical output transistor heatsink) that is a very common failure on these sets. When replacing, use a 100V high temperature (105 degree) capacitor. The originals were either 50V or 63V, 85 degree, and they failed often. Another high failure capacitor is the 100uf, 200V capacitor by the flyback. When it fails, it often burns up the horizontal centering control. I can't remember the value; but, there is another capacitor in the B+ line to the video output stage and if this capacitor opens, it will cause a smeary picture with one side of the screen being darker than the other. It will be a HV cap of at least 250V, probably in the 4.7uf to 22uf range.
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http://www.youtube.com/user/radiotvphononut |
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AND_-if this is a monitor-type set--it MAY be a "PM' chassis, similar to the PC, but with an SMPS supply on the side of the chassis and an AVIO package. |
Audiokarma |
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Looks like its a PM to me. I remember the set but not the guts.
Best to pull the back & find the chassis # & the mini-manual. As far as caps go a recap is a fools errand. 'Lytics in the power supply, vert & horz are 99% of the problems. Any others are only suspect rarely on "modern" solid state sets. GE which I hated actually built some very good sets in the end (1980's) like yours. Nice to see some survive. I miss working on them 73 Zeno |
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Was the PM chassis a real GE design or had Matsushita stepped in by the time they came out? I know the PC chassis was a real GE chassis made in USA. I had a nice clean 19" PC with electronic tuner from '84 or so.. It had excessive width, as its only problem, and 1 slip of the screwdriver took out the HOT. It's still sitting in the attic. I saved it because the thing looked like it had no hours on it.
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board. Used in better sets with comb filter, VIR, better audio etc. The PC was no slouch, I loved them. Only a few things went on them & they always looked damn good when done. 73 Zeno |
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The popping noise could just be corona arcing around the flyback, or around the suction cup at the CRT. Also the high voltage might be running too high, as that would also cause it. It's normal to hear some crackling when the set is first turned on and turned off, when the HV hits the picture tube. Corona arcing can also cause streaks and speckles in the picture. Also the capacitors mentioned, it would be a good idea to change them. Easy job. I remember changing a lot of those. If your getting HV, (which you are), I doubt if the flyback is bad. Could be some arcing around it, and if there are cracks in it, you can use some high voltage dope, (It's sort of an insulating paint), paint it on where it is arcing and let it dry good before powering the set up again. Humidity and moisture can also cause it to arc. As the set warms up, the moisture and condensation goes away and the arcing stops. I've experienced where people bring a TV inside after it has been setting in the cold, (especially in the winter), turn it on, and snap, pop, crackle, and they end up blowing other components. I bet if you do have to replace the flyback, you can find them on the web. Just google the part number, and do some searches. MCM electronics used to have a lot of replacement flybacks. Watching your video, it also could be the focus voltage arcing in the CRT socket. Also clean off the flyback, especially where the wires exit the flyback, and if there are cracks, see if you can get some HV dope and coat it. If you have a HV probe measure the HV to see if it's within specs, and also you can run the probe around the flyback to see if you get any discharge around or through the housing of the flyback. Just make sure you have the ground wire of the probe connected solid to the chassis ground, or yes, you will get bit!
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Brian
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Brian USN RET (Avionics / Cal) CET- Consumer Repair and Avionics ('88) "Capacitor Cosmetologist since '79" When fuses go to work, they quit! |
Audiokarma |
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Pardon me if i come off sounding like a noob. I was wondering how you got the time and weather to show up like that? is it part of your cable or a function on the tv perhaps?
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#12
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I know some of you want to see some more photos of the TV and I plan on taking some more tomorrow. |
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