Olympic model 950 issues that maybe someone has an idea

[kramden66]

This olympic set i was hoping would retore without any issues , the sound was one that i think i've cured other then a buzz in the audio that only goes away if the volume is turned up all the way , i can live with that and could live with the next issue that i can't seem to be able to get the horizontal circles proper , the right side squeezes a little , the drive helps a little and the lin barely but here are the true issues , the top of the picture bends for some reason that i can't figure outr , if i were playing a tape i might think this is normal but its a dvd , now add to this when the set runs after about 15 to 20 minutes it becomes wavey , if i rotate the horz hold it gets worse and looks like the old scrambled images on cable , i tried all kinds of tubes and when i changed the 6sn7 sync amp / sync sep it stopped only to return after 10 to 15 minutes , all resistors were checked , all caps replaced , any leaky micas replaced , the only thing i can think of is theres a mica or resistor somewhere in that circut that gives up after getting warm / running a while unless someone knows something different ( the crt ? ) the vertical doesn't seem to be affected by this , another thought was agc but i can't put a finger on what to replace.
sorry for the bad pictures taken by my cel but here they are
mike

[kramden66]

one more picture

[earlyfilm]

Originally Posted by kramden66

... i can't seem to be able to get the horizontal circles proper , the right side squeezes a little , the drive helps a little and the lin barely but here are the true issues , the top of the picture bends for some reason that i can't figure outr , if i were playing a tape i might think this is normal but its a dvd , now add to this when the set runs after about 15 to 20 minutes it becomes wavey , if i rotate the horz hold it gets worse and looks like the old scrambled images on cable , i tried all kinds of tubes and when i changed the 6sn7 sync amp / sync sep it stopped only to return after 10 to 15 minutes , all resistors were checked , all caps replaced , any leaky micas replaced , the only thing i can think of is theres a mica or resistor somewhere ....

I can't be more specific, as I have not seen a schematic of your set.

Your photographs indicate a signal overload somewhere.

You most probably have a gassy IF tube. Next probabilities are flaky AGC tube or gassy tuner tube. The high value resistors in the AGC circuit and the resistors in the tube that supplies the keying for your AGC are suspect.

James

[kramden66]

I tried the tuner tubes , only one of the if tubes did i try , tried the video det / agc rect tube , tried the sync amp / syncsep tube , tried the horz afc / horz osc tube , tried others like the horz out , the damper ..... just tried it cold and the picture is ok , i did have to touch the horz freq adjustment because i couldn't get a straight picture, i can obtain that scrambled look by decreasing the contrast till the signal gets weak and if weak enough the vertical gets effected , i can not overload it when the set is cold or when the problem occurs ... can't put up the schematic because i don't have a scanner but could take pictures of it which might not look so good with my cel but can try another one.
whatever is the issue here it is definately something that after it gets hot then it happens and vertical is not effected.

mike

[dieseljeep]

Originally Posted by earlyfilm

I can't be more specific, as I have not seen a schematic of your set.

Your photographs indicate a signal overload somewhere.

You most probably have a gassy IF tube. Next probabilities are flaky AGC tube or gassy tuner tube. The high value resistors in the AGC circuit and the resistors in the tube that supplies the keying for your AGC are suspect.

James

I don't think those older, simpler sets used keyed AGC. They used an AGC circuit similar to the AVC circuit used in radios.
A lot of good advice in this entry.
Make sure no IF tubes were subbed either. That is, a sharp cutoff tube used instead of a remote cutoff tube.

[kramden66]

now i'm wondering if a cold solder joint could have caused this problem since I redid it the set hasn't done it again , I ran it two times for an hour and its ok , still has the bend at the top but if that's the worst I will deal with it since rotating the horz to fix the bend if you do the picture gets wigley and then slips to the twited image but runs stable with the bend.image

on the third play I had something happen I wasn't expecting , a replaced cap when pop and a puff of smoke came from it , a 47uf at 160 volts , now either the cap was crap to begin with or there is more then 160 volts running there , its supposed to be a 150 volt max cap , I will investigate further to see what voltage is there , also wondering if this helped cause the unstable image.

mike

[kramden66]

There is no start up voltage and it rises to 95 volts so the capacitor must be at fault , its made by jakec , a Chinese brand ? I have others like it that were used in sets and i'm wondering if this was just a bad one or if they are going to go bad too , it was hot after it popped but no idea if it was getting hot when first installed or it would have been examined and pulled before it blew.

mike