jeff@cs.tamu.edu (Jeff Goldberg) (08/27/90)
A couple of days ago I was watching my TV (1984 Sony Trinitron) during a Texas thunderstorm. There was a lightning strike *very* close to my house and my TV went out. The TV acts like it is getting no power at all. The circuit breaker in the house was not blown. I assume lightning is a high voltage as opposed to a current surge. I should add that I am a computer scientist with no real experience in electronics so I am in need of *basic* advice. I followed the part of the circuit that the power cord goes into and saw the "main" fuse was intact. There was one additional fuse (away from the power supply part) and it was also intact. I was looking for a "kind of power regulator" component just at the point where the power goes into the "main board" but this seems to be difficult to spot without a schematic or knowing exactly what to look for. Any suggestions for things likely to have been damaged by such a storm? How likely it is to be something I can learn to fix? How extensive the damage is likely to be/How much to expect to pay to get repaired?
reilly@motcid.UUCP (Patrick L. Reilly) (08/28/90)
jeff@cs.tamu.edu (Jeff Goldberg) writes:
:A couple of days ago I was watching my TV (1984 Sony Trinitron)
:during a Texas thunderstorm. There was a lightning strike *very*
:close to my house and my TV went out.
:The TV acts like it is getting no power at all. The circuit breaker
:in the house was not blown. I assume lightning is a high voltage as
From the world of a former TV repairman...
Try checking the power suppply diodes. Should be near the
power cord and either consisting of 4 small black round
objects with a silver band at one end. OR, may be a
single square package with ~ & + symbols on it.
Diodes should read low ohms in one direction and very high ohms
in the other direction using the diode selection on your voltmeter.
I suspect one is shorted.
Another possibility is the start up circuitry that is used to
protect against excessive X-ray outputs when the high-voltage
circuit is defective. To check this, you will need a variable
voltage source. Try turning on the set at about 90 volts. As you
crank up the voltage the start up circuit will kill the set.
Finally,
I used to charge $50 EXTRA just to service a SONY TV!
Why? They are great sets when they work, but their elaborate
systems of closed loops causes plenty of troubleshooting grief.
Good luck.