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  #1  
Old 08-14-2014, 08:22 AM
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63 sivertone roundie again

hi all, i am trying i think one last time to narrow down what is wrong with this 63 silvertone ctc12 clone. to keep it short i just put a new flyback in this set because of hv issues but only to find out that the focus circuit was wired wrong so i corrected it and now i have hv where it should be but with the hv adjust at max. the problem i have been having is setting the drives up i have red, green , blue lines across the top of the screen about 2 inches down and much worse if the crt bias is raised so the bias is at min but still have the lines faint. it is like the drives are being driven to hard and cannot figure out why. no matter how i adjust the color even by the sams setup procedure it still is not right. all i want to do here is get the picture bright with good colors and no lines, like my other sets. its like there is a problem in the bias circuit, i checked the bias pot its ok, but maybe a problem befor the the pot in the circuitry, i just dont know. if the drives are down adjusted low and the bias is used alittle to get the weaker gun to show color on setup then after the switch is put back to normal the lines are worse and to high on the bias and the picture will bloom as if the bias is maxxed. tried different tubes but none make any difference. i am thinking there may be a problem in the chroma board like maybe a cap in or around the color amp tubes, 6cg7 or the 6gy6. any help would be great at this point because i am out of ideas,lol...
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Old 08-14-2014, 09:56 AM
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did you check L14 in the crt cathode circuit like I mentioned originally.
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Old 08-14-2014, 10:31 AM
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L14, i dont remember but would i be checking for an open or short and i think the sams says there is a 2200 ohm resistor to do with that L14?
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Old 08-14-2014, 11:06 AM
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you need to look at the sams. it attaches to the service switch.

Next you need to resolve the HV it should not have to be set at max

you need to check the HV and the shunt tube current to make sure all is working correct. AFTER you get all that worked out then you can start working other issues.
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Old 08-14-2014, 11:36 AM
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as far as the hv, i also checked the hv pot and checks good, ohms, and i also tried several 6bk4 tubes as well as checking ohms on the 2 resistors that are said to be matched but mine are not. all this was done befor finding out that the focus circuit was wired wrong but since fixing that problem the hv is at 24kv and dont dip on white scenes or any other scenes for that matter anymore except if the bias is raised just alittle. and yes i see L14 is connected to the service switch, but what is it im looking for with the L14. all the resistors around the service switch test what they are said to be. if i get into the procedure of checking the ma for the shunt tube and it comes up way off in some way which direction would i go to correct that. these tvs are alittle difficult for me as i am not nor was i ever a tv tech but rather an auto tech, but i do try.
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Old 08-14-2014, 12:13 PM
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sams covers how to check current should be between .75ma(bright) and 1.5ma(dark) IIRC.

you need to make sure the line is set to 117vac

have an HV prob to monitor CRT anode voltage

have an meter to monitor the cathode current of the Horz out

have an meter to monitor the current or voltage drop (where a resistor is used)on the shunt.

adj eff coil for dip on horz out coil (should be around 190-200ma)
adj voltage HV pot for 24kv on dark screen
check shunt currrent or V drop on 1k resistor look for 1.5ma dark .75 bright
if all this checks then HV is ok.

This is standard stuff that should be done anytime you put in new HV tubes (horz out/damper/shunt/HV rec).

if you are ok with this then post a pic of the problem. or better a video.
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Old 08-14-2014, 12:28 PM
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well ok, but i dont have all the meters required for that procedure and a pic im almost certain the lines wont be seen as i dont have anything worth taking a good pic. and the line voltage well im at the mercy of the grid it self,lol lol. ok ill see what i can get as far as several meters, i do have 1 ma meter and hv prob and a fluke dvom.
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Old 08-14-2014, 12:37 PM
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I dont know if HV setup will have anything to do with the color problem you noted, but when you said you have the HV adj maxed out, a few red flags went up.

So.. I would make sure there are now issues there (HV). It may be as simple as a weak Horz Out/damper/HV rec all of which would limit the HV output.

Generally speaking if HV is not acting "right" as in having to run max setting, then start with those tubes by SUBBING known good tubes, I will often try several. btw how is the width?

Now that we have addressed the HV, without a pic its very hard to diagnose, a video is better still for the color problem.
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Old 08-14-2014, 01:01 PM
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well its funny you ask about width, well the old fly and the new both seem to share the same thing and that is the width is fine but when it comes to centering the pic the horiz centering pot is almost all the way to one end of the pot and some scenes can be seen as the centering is to much to one side but it fills the whole screen. if i took an image and centered it there would be something missing on the screen but with the bar dot gen i can center the pattern fine. ill put fireworks inside and light them up,lol,lol
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Old 08-14-2014, 01:18 PM
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make sure the 10 ohm pot is not open
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Old 08-14-2014, 01:33 PM
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horiz centering pots on both the nos fly and the old fly both check exactly where they should be. this set i think is cursed,lol,lol...
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Old 08-14-2014, 01:38 PM
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you took the horz centering pot out of the circuit and tested for continuity and action of wiper? an analog resistance meter is best for this.
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Old 08-14-2014, 02:10 PM
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yup there both good and besides what are the odds of a new one and an old one both being bad or doing the same thing. i think its safe to say this set is wacky.
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Old 08-14-2014, 07:09 PM
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don't forget to check the boost rectifier diode
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Old 08-15-2014, 10:15 AM
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i dont believe there is a boost rectifier diode in the ctc12 clone, well i never found one.
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