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#1
11-06-2014, 09:27 AM
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65 silvertone
ok so i have another silvertone this one is a 65 and it works fine however i have a focus issue where when i turn it on as soon as the picture appears its sharp and clear but after about 30 seconds it gets blurry and out of focus and then after about a minute and a half its clear again and fine from that point on. i already replaced the rec stick , 66 meg, 6kv cap, and a 1 watt resistor, forgot what the value is but i changed it. is there anything else i should be looking at as a possible cause for this. i know it should not come on clear then go out of focus then clear up. its a though something warms up, the flyback is new and all the focus components except the focus coil.
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#2
11-06-2014, 10:39 AM
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does it always take the same amount of time, each time it does it...?
Have you tried wacking it when it goes in or out of focus to see if it's a bad connection...? .
__________________
Yes you can call me "Squirrel boy"
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#4
11-06-2014, 12:57 PM
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Did the set have this problem when you got it, or is this a problem that cropped up
after replacing parts at random....? If it does this reliably then you should monitor the focus voltage and see what's going on before replacing more stuff... If the focus voltage goes up or down, look for parts in that circuit.... It's a simple circuit, or is it some other HV related problem.... Troubleshoot carefully....
__________________
Yes you can call me "Squirrel boy"
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#5
11-06-2014, 02:47 PM
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had the problem when i got it but the parts i replaced helped it to be much sharper focus once its cleared. hv is adjusted and where it should be and i already did check the focus voltage and it never went up or down it was where it supposed to be.
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#6
11-06-2014, 04:22 PM
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Well, if nothing else is changing with this symptom then you should look at the
voltages of pins on the picture tube that can change and cause this.... Common to all 3 guns, like focus, other grids where all three are common. Is HV stable...? Source voltage to the 3 screen adjustment pots.... Just before the focus grids.. When I say monitor the focus voltage, I mean stick the meter on it till it goes out, and then comes back into focus all by itself.... Even if you take 5 hours to let it cycle through a few focus cycles.... Diagnose it before replacing stuff... And during this time does anything else happen...? Screen width, height, sound...? No snapping sound...? Good ground on the picture tube...? How about B+ Boost 386v is it steady while this happens....? Put the meter on it and watch it while it cuts out.... then comes back.... I'm just guessing what chassis this is.... ctc12....? anyway, same ideas, different chassis.. If you got chassis number post it, if there is a link to schematic post it, or do the conversion to appropriate parts off the ctc12 schematic I found off google. .
__________________
Yes you can call me "Squirrel boy"
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#8
11-06-2014, 07:04 PM
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This is better looked at as you set up a meter to monitor the voltages using clip leads
or something you have, set it up then turn on the set and wait for the show.... .
__________________
Yes you can call me "Squirrel boy"
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#9
11-06-2014, 09:03 PM
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I've got a 64' model that has a brightness/contrast issue that behaves the same as your focus issue...So far I've yet to track it down.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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