The Sony Trinitron won't start,..

[raymond@f_ing_swave.com]

Hello, when we push the power button there is no response; nothing
lights up at all. My neighbor said if he remembered to just push the
button once it would all of a sudden come on by itself after a half
hour or so and everything would be fine.
I removed gobs of dust and checked the fuses a wiggled the
wires/connectors. The ON button is kind of pressure button that runs a
flip-flop circuit but disapears into the maze. The power section has
ac but no dc. I was hoping this is a common problem or easy fix for
someone familiar with tv repair. Thank you.

 

[JANA]

Thermo sensitive parts. After the power is on for a while, they heat up and
drift close enough in to specs. When cooled down, they are out of specs.
Most of the time, it is capacitors that can become thermo sensitive with
age.

--

JANA
_____


Hello, when we push the power button there is no response; nothing
lights up at all. My neighbor said if he remembered to just push the
button once it would all of a sudden come on by itself after a half
hour or so and everything would be fine.
I removed gobs of dust and checked the fuses a wiggled the
wires/connectors. The ON button is kind of pressure button that runs a
flip-flop circuit but disapears into the maze. The power section has
ac but no dc. I was hoping this is a common problem or easy fix for
someone familiar with tv repair. Thank you.

 

[I.F.]

Hello, when we push the power button there is no response; nothing
lights up at all. My neighbor said if he remembered to just push the
button once it would all of a sudden come on by itself after a half
hour or so and everything would be fine.
I removed gobs of dust and checked the fuses a wiggled the
wires/connectors. The ON button is kind of pressure button that runs a
flip-flop circuit but disapears into the maze. The power section has
ac but no dc. I was hoping this is a common problem or easy fix for
someone familiar with tv repair. Thank you.

The most common cause of this type of symptom is the start up resistor going
high in value. Whatever chip the PSU uses must have some form of Vcc supply,
once the PSU is started this supply comes from a winding on the chopper
transformer but to get started in the first place there is usually a high
value resistor from the reservoir cap +ve to the chopper chip, value varies
depending on design of circuit and is often 2 resistors in series and can be
anything from abou 68k to 180k.

 

[Andy Cuffe]

Hello, when we push the power button there is no response; nothing
lights up at all. My neighbor said if he remembered to just push the
button once it would all of a sudden come on by itself after a half
hour or so and everything would be fine.
I removed gobs of dust and checked the fuses a wiggled the
wires/connectors. The ON button is kind of pressure button that runs a
flip-flop circuit but disapears into the maze. The power section has
ac but no dc. I was hoping this is a common problem or easy fix for
someone familiar with tv repair. Thank you.

Depending on its age, it could be a problem with the power relay, or
the circuit that controls the relay. I've seen power relays in Sony
TVs that no longer close reliably.
Andy Cuffe

[email protected]