Flyback Transformer for Philips Widescreen TV

Be extremely careful when working around the flyback circuit. That CRT is also a high voltage capacitor that can store a lethal charge for a long time. Always ground out the high voltage sections first.

That being said I would also check the transistor that drives the flyback, they seem to fail quite often.

Hello,

When the horizontal circuit fails or shorts. This puts a very high load on the switch mode power supply and keeps it from starting and this in turns keeps the SMPS (for short) from starting up.This is the chirp you are hearing as it tries to start.

Philips tv's were bad for the solder joints around the horizontal transistor and the heatsink it mounts to to crack and the flyback transformer can develop cracks around the pins as they pass through the board.

So some of the checks are to look for these cracks and to remove the solder from all the joints and if you can get it, use real solder 60/40 or eutectic 63/37 solder and not the non lead type solder.Then re-solder the connections.

Another test is to check the horizontal transistor out of circuit to see if it's shorted.

Most likely it will be shorted but horizontal trans do test differently because they have a "flyback diode" in them. just find a spec sheet on it to guide in your testing of it.

Like some have said there are repair kits that should have most of the parts for a normal repair.

To temperately try to power up the tv is to use a 100watt light bulb inserted in the DC voltage line to the collector of the horizontal transistor. This trick should/will let the set power up minus the power supplies generated from the HIGH VOLTAGE CIRCUIT.

Just don't run it to long as it can damage other parts. Also the brightness of the buld is a good indicator of shorted parts. Bright = shorted high current draw, med = lower current draw may be ok?

Just be carful the voltages on the DC supply can be up to 175 volts or more and enough current to KILL.

All this said, it is just enough info to get you in to trouble if your electronic skills are not up to doing this proper. TV CRTs can carry a healthy jolt even after they been discharge, they sorta regenerate voltage back unless shorted for a long time, and thats no guarantee.

So my suggestion is to get either a factory service manual or SAMS manual they are good also, just reversed engineered so they flow a little different than factory IMO.

OR to save your self some headache and grief take it to a reputable service center and let them repair it and do a proper setup and check the crt. If the shop is good the and the sets crt still has life in it. Then it will come back to you almost as good as new.

Rule of thumb is repair should be around 1/3 -1/2 cost of a new set for service shop. If the set is 3-6 years old it's may be a good candidate for repair. If set is over 6 or more years old you might think about just replacing it.

Hope this helps you to decide.

metalSmith's