Quote:
Originally Posted by rca2000
Off of the grid pin--pin 2--there is a choke--l15--should read 10 ohms. Ths is paralleled by a resistor--R65, shoukd be 4.7K.
SOMETHING..is OPEN here.
ALSO..On the OTHER SIDE of L-15 is the delay line. COUld be open. if not...on the other sid eof it...is ANOTHER choke--L-12. 5.2 ohms. Then...it goes to a transsitor--Q5--the 2ND video amp, collector pin. SHould read 11.6 voilts or so. ,Base should read 16 volts, emitter 16.5 volts. lThis is a PNP transsitor---it relies on a differential i voltages on base to collector--toi conduct. base goes CONTRAST control--which is connected to 21 volt line.through R-61 18K.
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You sure you're looking in the right SAMS? because there's no R 61, 65, or 70 anywhere near the 12HL7 tube. Also to my knowledge this TV does not have a contrast control... or at least I can't find it.