Hitachi CT13C2 vertical screen distortion

[StarquestMan]

well i checked out that cap and it was reading 28v across it. i should mention that the waxy coating i found was very very thin like hot engine oil residue or penetrating oil of some kind it definitely was not candle wax, in fact the only reason i guessed it was wax was because i could see a glossy reflection on that wax dipped cap and was able to wipe it right off with my finger when the set was running. i did notice that some of the electrolytics near the flyback and power supply section were warm to the touch with the set running last night and i will definitely check them out since they tend to dry out especially with heat. i hope the pictures i uploaded will work. i dug out my pattern generator and used a crosshatch pattern that shows a bit of what is happening but i can definitely take more if needed.

[StarquestMan]

well just after posting my last post i started looking at the residue pattern again and noticed that it may be coming from that dark brown Nippon Chemi-Con cap at c903 and running back towards the flyback making it look like its originating from the wax dipped cap next to it. now that i think of it this capacitor seemed to stick out as being the warmest cap i found.

[zeno]

C903 is in 135V regulator so try it. Also check for 135 VDC at
pin 6 of the FBT or pin 7 of the reg module CP901. Must
be 135V !
BTW the screen shot dont show much, in the case use a
few real pictures.

73 Zeno

Originally Posted by StarquestMan

well just after posting my last post i started looking at the residue pattern again and noticed that it may be coming from that dark brown Nippon Chemi-Con cap at c903 and running back towards the flyback making it look like its originating from the wax dipped cap next to it. now that i think of it this capacitor seemed to stick out as being the warmest cap i found.

[StarquestMan]

sorry i took so long to get back to this thread. here are some more pictures i took unfortunately none are of a moving image because it was impossible to take a picture with my camera at the precise moment something would jump off/on screen but i did find some menus that had a bright section that would have a similar effect.

i haven't checked that 135v rail yet but i will definitely do that once i pop the set open again. is there a certain tolerance that is acceptable? i am very suspicious of the cap at c903 but i cant find any lying around that are high enough voltage so i will have to order it if it is in fact bad but i will check the 135v rail first. which brings me back to one of my original questions as to weather or not i should do a full recap of the set? also if i do will everything have to be completely re calibrated to compensate for the new caps or will it just be "better than original" and improve the overall sharpness and clarity of the set? i guess im wondering because i recently recapped an old pioneer and the improvement was huge and was wondering if tvs benefit in a similar way?

(quick update-i just tested the voltage between pin 6 and 5(gnd) on the FBT and got 136.3 volts so i assume this is fine?)

[zeno]

Pix has bending so try C903 first.
Then try turning the briteness all the way down & see
if the 135 V goes up.
BTW do you have a variac ??
I would not recap this set or most modern solid state sets.
Costs add up & things often go wrong. Just change the known
trouble makers.

73 Zeno