General information

Job Number	0304-77
Equipment type	TV (17”)		Made in:	Belgium
Maker/Model/Chassis	PHILIPS	42KT3150		KT3 chassis
Dates 2003	In	Repaired		Out
	Wed.02.Apr	Mon.07.Apr		Sat.12.Apr
Comments	TV was bought 2^nd hand for 20Euros. It was severely repaired, as if it was in a repair-education school for novice students.

Symptoms observed

1	Turns off (dead) immediately after switch on

Repair notes

Full repair description and observations
1	Very strangely, when the TV set was opened, and the chassis was turned from vertical position to horizontal position (for servicing and diagnosis) the TV worked perfectly (raster present)
2	However a very abnormal whisling noise was produced from somewhere in the circuit, presumingly the High voltage transformer. On better checking, to my astonishment, there was sparks from the EHT transformer High tension wire (carrying the 20kV). The TV was switched off and the High Voltage (on the CRT plates) was discharged carfully to earth
3	The EHT wire was burnt and in consequence slightly perforated. At first I taught that a previous stupid technician by mistake touched the wire with the soldering iron and hence melting/burning the plastic insulation of the wire. On more evalation, I noted that there was plastic meltings/burns on a high wattage resistor, in close vicinity to the wire. What happened is that the EHT wire touched this resistor. On operation the resistor became very hot and as a result it melted slowly the wire insulation until it became perforated. Probably a spark passed into circuit causing it to switch off.
4	The perforation was properly insulated using evostick glue, then few rounds of electric tape, and a pull-to-tight plastic band (I don’t what it is exactly called) to keep everything in place - with time and heat the tape glue can wear off and the tape may fall.
5	I put the chassis back in the original upright position and switched on. The TV switched but there was no focus!!! Turned off again, and noticed that focus wire came free of from trippler. Resoldered it again, turned on and TV was OK. No whistling sound was produced from the EHT wire.
6	I noticed that the picture was a bit dark (even on full brightness controls). There was no G2 adjustment and R,G,B presets on CRT plate where already set to maximum! However there was a preset (R422) which increased the contrast and this helped to make the picture brighter and, on the whole, better.

Repair summary

INSULATION OF EHT CABLE PERFORTAED

Precautions, fouls and advises
1	I managed to get a nice eht shock. The sound was more scary than the pain itself. When working with EHT, always discharge EHT capacitor (tube) by a high Ohm resistor for sake of safety

Other measurements and technical comments

1