tv trouble shooting part two(visiual inspec)

so we come up on a tv chassic you never seen before on a service call.lets say dead set with out a print analog chassic. the first thing i do is follow the power cord and locate low voltage power supply check fuses .also some tech do not realise that low ohm resistors 10 ohms are really fuses anything ten ohm or lower are fuses sand block resistors 2.2 ohm 10 or 15 watt are really high current fuses check sand blocks also. again look at caps for clue to what the voltages might be.the first thing i do is check voltages at collector of the horizontal out put transistor should be 126 volts to 146 unloaded horizontal is high voltage power supply if voltage is missing go back to low voltage power supply check the voltage at rectifier bridge cathode if present should be in the area of 126 or 136 volts dc.so between what do you got let see hand full of caps 250volt possible or open resistors then theirs stk packs voltage regulator 126 in possible 136 out to collector to horizontal out put.then their s the high voltage supply that we will cover in the next editioral.you do not need a print to trouble shoot this circuit on this service call power supply method trouble shooting is the same.also a quick visiual of circuit board for burnt or discolored componients turn board over and look for dark areas will tell you somrthing not right and it that general area componients got hot and start checking that area this is something i pick up over twenty eight years doing serviceing in the home. we will cover this also till next time have a nice day.



clue to tell if a capacitor might be bad look for domeing on top of a electrolitic also yellowish/brown substance at the base where the cap leak its dielectric on circuit board and has glued cap to the board careful removing seen it many times in small tvs sets where is a lot of heat.

Post edited by: hobbist, at: 2008/05/05 00:27

Post edited by: hobbist, at: 2008/06/05 18:31

How to Measure magnification
How can I see how strong a magnifying glass is?


I bought this magnifying glass http://www.liangdianup.com/inventory/189901.htm and I want

to know how to test it to see how strong it is. I hear a lot of people talk about

magnifying and how strong the magnification is, but I would like to know the true

magnification of my magnifying glass. I have a few of them and some seem stronger then

others. How can I rate these? How can I pin a correct number on mine? How do the companies

that make these come up with these numbers.

they are measured same as reading glasses.go to an eye ware retailer and get a flash card with letters and bar code graffics.that are set for each eye glasses mag.