If the problem gets better suddenly, then look for bad solder joints
(can be invisible without strong light and a magnifying glass), but if
it gradually improves, suspect a worn-out capacitor. As people much
more knowledgeable have said, the fault is in the horizontal
deflection circuitry. The PC board should be labelled by section, or
you can trace the 4-6 wire cable going to the yoke of the CRT (yoke is
that big coil around the neck).
Be careful not to let the TV fall forward, which it can easily do
because its center of gravity is only 2" behind the screen. One
person mentioned placing a CRT on a bed and seeing it fall forward and
tumble to the floor, so either place it on a solid horizontal surface,
or place it face-down on a soft surface.
Apparently Japanese CRT TVs at least 15 years old were built better
than newer ones and had CRTs that would last a long, long time. I'm
still using a 34-year-old Sanyo that still works well and has needed
only 2 new capacitors.
I had a CRT that would go red after being on a few minutes. I took the
cover off and while it was on, poked around the components with a 2
foot wooden dowel until I found one that resolved the problem when I
held pressure on it. Unplugged the TV and checked that board from the
other side (staying well away from any big caps) and found a circular
crack in the solder around one leg of that component. I remelted the
solder and it was fine for several more years.
I just wanted to some what you can realistically do.
This is likely a cap problem. If you look at the top of an electrolytic
cap it will have a cross scored "vent" on the top of the cap. Damaged
caps will often appear slightly bulged there. Look for one and replace
it with one of the same value and the same or higher voltage rating. The
negative end is marked, make sure the polarity is correct.
This may, or may not, fix your problem. But it is in the low dollars to try.
The effect's called pincushion; it's unlikely to be the CRT itself -
chances are a bad capacitor in the horizonal deflection or something
specific to the pincushion correction circuitry (bad transistor, bad
solder joint etc.)
See if you can find a schematic online. Might take a bit of digging
because some chassis are shared between manufacturers or between models
from a specific manufacturer, and the schematics are often filed by
chassis designation rather than whatever manufacturer / model number is
printed on the back of the set.
1) TVs are about the worst-built of any consumer appliance; just about
everything's designed to be as low-cost as possible so that the TV works
when you buy it but doesn't necessarily last for long. Bad solder joints
aplenty, and cracked PCBs aren't unheard of. You may be looking for a
mechanical fault rather than component failure.
2) Some capacitors fail in an obvious way - sometimes with can-style
electrolytics they'll visibly bulge and split and show signs of
electrolyte leakage. But most don't die that way, and you'll need an ESR
meter to detect faults (the other approach is to trace the fault to the
most likely area and simply replace all caps in that area)
3) Serious voltages inside a TV, and stored after the set's switched off.
I've only been zapped by a TV's HV once, but it's not something I'd care
to repeat - unlike the brief ouch from an outlet shock, TV HV *hurts*. Be
careful (if you've been inside TVs before you probably know this, but I
figure it doesn't hurt to mention it :-)
There's a huge amount of useful info on the repair of TVs at:
Anyway, yes, it's fixable - but only you can decide whether you want to
invest the time :)
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