If you do not feel comfortable performing these repairs, or feel
you are not qualified to perform these repairs in a safe manner, please do not
risk trying to do so. Seek the assistance of a qualified service technician. Always unplug TV’s AC power cord from the
wall before: Removing or reinstalling
any component, printed circuit board, module, or a plug connection.
Never use a heat sink as a ground connection for your test
equipment. You should find the proper chassis ground for this.
If you are working on a CRT type projection TV set, you have three
picture tubes that should be discharged to prevent accidental shock. You can
discharge the picture tube’s anode at any of the R, G, or B outputs on the High
Voltage distribution block only by:
First connecting one end of an insulated clip lead to the ground
on the back of the picture tube, or the mounting plate of the picture tube.
Then touch the other end of the insulated clip lead to the wire coming out of
the High voltage distribution block, or by using a long handled screwdriver,
with the clip lead attached and slid up underneath the rubber boot on the
picture tube High Voltage connection.
All TV sets that have a picture tube will have a high voltage
transformer with a heavy red wire that runs up and connects to the picture tube
with a suction cup. Under there is an average of 32,000 volts when the sets on.
Even when the set is off, it can hold a large electrical charge. If it zaps or
bites you, it can make a grown man cry, and not only that, can stop your heart!
Therefore, the point is to never ever stick a screwdriver under the HV cap even
if it is unplugged
If the cap has to be removed, attach one end of a clip lead to the
metal exposed strap that is around the picture tube, and the other end to the
screwdriver. Without the metal blade of the screwdriver being exposed to you,
slide the screwdriver under the cap slowly. There should be a little pop if
there is any voltage left. Wait for a second or two, remove the screwdriver,
and pinch the top of the cap perpendicular to the wire while pulling up on it.
Never pull on the wire. With the cap off, clip the clip lead to the anode
connection on the tube while the other end stays on the grounding strap.
