On 1/16/2011 10:25 PM, Tony Miklos wrote:
On 1/16/2011 9:18 PM, PE wrote:
Hi all: My 15-yr old Toshiba 27" crt television has recently developed a
problem which is that approx 15 minutes after being turned on, the
picture
bows inward on the left and right sides. Then, after a few more minutes,
the picture resolves and returns to normal and remains perfect for the
remaining time the tv is on. If the symptom described above means the crt
is wearing out, so be it, the set will soon be history. However, I'm
wondering whether some other, replaceable part, might be going bad and
causing the temporarily distorted picture.

Would appreciate any suggestions re. probable cause(s) of symptom
described
above. Am basically novice, but handy and with soldering skills, and have
done a few simple tv repairs in the past. Thanks for your replies!


I'll bet it is a bad capacitor, fixed hundreds of video game monitors
with similar symptoms. Most of the time we don't even test the caps,
look for parts of the circuit board that look like they run hot, then
replace all caps in that area. Also replace all caps rated for 100 volts
or higher, they go bad much more often. Also if you know your way around
a monitor, be sure to change the caps in the vertical and horizontal
circuitry. For newbies in the video game monitor repairs, lot's of
people put together a list of all the common caps that fail on that
particular model and sell you a bag of caps and a picture showing what
goes where. The "cap kits" will fix several problems at once, including
problems you didn't notice yet but are about to go.

Actually my TV is doing the same as yours but it stays that way. When it
quits I'll probably take a look inside, but chances are I'll toss it and
get a new one instead of fixing mine. TV's have a lot more components
than cheap video game monitors and aren't as easy to fix (not for me
anyway).

OH, no way is that a sign of a bad CRT, and no way is the yoke itself
bad, just the circuitry that powers the yoke.

You beat me to the bad capacitors. 15 years is a darn good life for
consumer grade electrolytic capacitors. I had a customer who's Viewsonic
LCD monitor on his server/office computer died after a year.
I thought it a shame to toss a nice monitor so a little Google search
turned up a common problem with an electrolytic in the power circuit
on the main circuit board. The store had a problem with recurring power
surges and even though there is good surge protection on the computer
system, what can get past the surge arresters will damage some
components. I believe it was a 100uf 16volt electrolytic and when
looking at the circuit board I noticed lands on the board for a parallel
capacitor. I installed two 47uf 35volt caps and there have
been no more problems with the monitor.

TDD