sony 3400 v2

Ramji · Guest

i got a sony 3400 v2.chasis is SCC-C29E-A.The picture is wavy.I found one of the filter capacitor C619(850mfd/250v) is getting too much heat and causing problem and one of the resistor 330k has gone high value.Replaced both the filter capacitor in the powersupplu and the resistor.Now when i power on the tv is trying to start and the buse gets blown.The capacitor c619 is getting too much heat.What might be causing the capacitor too get too much heat.Need Solution.

With Regards,

Ramji

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

1) Installed Backwards.

Guest · Posted: Tue Jan 27, 2009 9:05 am Post subject: sony 3400v2

the capacitor is installed correctly.but it is getting too much heat and the fuse blows off.

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

2) Exceeds Voltage Rating of Capacitor.

Guest · Posted: Tue Jan 27, 2009 2:45 pm Post subject: sony 3400 v2

I put a new capacitor which is mentioned in the circuit.In circuit it is mentioned c619(820mfd/250v).I replaced both the filter capacitor c618 and c619(820mfd/250v),but c618 is ok but c619 is getting heat immediately.

With Regards,

Ramji

LJ · Joined: 09 Dec 2008 Posts: 47 Location: Earth

I don't have schematics, wondering if you tell me, are both capacitor at regulator? are they both connected in series? is the resistor 330K parallel with the capacitor? if yes, try to check diode before capacitor, maybe it's short.
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jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

Measure Voltage across C619? (If more than 250 WILL overheat)

Guest · Posted: Sat Jan 31, 2009 12:59 pm Post subject: sony 3400 v2

One capacitor c618 is charged through bridge rectifier circuit and the other capacitor c619 is charged through STR81145A(Voltage Doubler).This c619 is getting too much heat when powered on.

With Regards,

Ramji

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

What is the measured voltage across C619?

LJ · Joined: 09 Dec 2008 Posts: 47 Location: Earth

Possibility:
-Over voltage at C619 caused by:
* C at pin1 and pin2 STR81145A defective.
* STR81145A defective.
- Bridge rectifier defective ( pin - ).
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