My rca, when started, the sound come on but not the picture
Either your RCA tvs horizontal oscillator section or it LOT [Line Output Transistor} has some trouble. You just open your TV and check the voltage at the LOT pin. It should be around 112VDC or so. Check the voltage at its line drive transformer also. It is a small transformer diretly soldered on to the main board, and can be located very close to the above said LOT. Check voltage at its primay side , and if you have a digital multimeter capable of measuring frequency, check the frequency at this point. It should come around 15500Hz or so, without video signal. As far as sond is OK, all othere sections, ie video IF, Tuner Audio output and so, are working properly, only horizontal output is not. Check the horizontal output transistor, which drives the LOT, can be located very near to the LOT screwed onto a metal heatsink. If it collector to emitter or collector to base junction has some leak, it won't work properly, LOT will not work, and there will be no EHT [Extra High Tension], and will be no screen at all. Check these. If you wants anymore asistance from me, get me through Fixya. The fault with your TV is no horizontal sweep. OK.
Jan 08, 2011 |
RCA F27442 27" TV