POWER SUPPLY PROBLEMS SONY KV35V36,32V26,32V36,34V36,35V36,35V76,37V36m

hAI REPAIR YOUR SONY TV......... KV32V26, 32V36, 34V36, 35V36,35V36C, 35V76,37V36M SMPS section. Problem: dead set….POWER SUPPLY PROBLEM...HORIZ.. PROBLEM (TAKE A BULB OF 60W TO DISCHARGE AND CHECK THE SMPS) 1.Remove from power and disconnect degaussing coil and main board.*** BE CAREFUL with the capacitors c 606 ,c607 and c 643. discharge it after remove from power. 2.Remove the rectifiers D615,D645,D644,D643 also remove D648 Zener diode(EZ0150A) and replace capacitor C643 with 220 mf,200v or higher.. also disconnect the diode D641 and D646. which is connected to the secondary of the SMPS transformer. 3.Now check the smps transistors Q601 and Q602 (2sc 4834MNP) if its bad replace it with any transistors with same parameters. And check the resistor r607 and r622 check the varistor VDR601 .(Short the legs of varistor until the repair is complete). Replace resistors r615,612 ,r613,r614 which is 220k.and R617,616,610,609 at 22ohms, Check the resistors R611, R 608, ,623 ,R607,R622.. 4. Replace capacitors c609 ,0 .47 and c610 , 0.47 5.check the diodes D603,604,605,606,607,608,609,610.(1ss119) if you can replace it with almost same parameters , which is used here as voltage stabilizers to transistor Q601 and Q602. 6. Now disconnect the resistor R607 and plug in to mains. 7.Check the voltage at point R607 +ve to R623 –ve. … ie ….floating negative.( negative on the primary side of the SMPS transformer is called floating negative, Never check multimeter between this side and secondary side)The voltage will be …. 8. If the voltage is around the diodes D602 and capacitors C 607 and C606 is ok …..but not 100%.( because still the any one of the bridge in diode D 602 may be defective) If no voltage then suspect the diodes, fuseF601 or the harsh filters. 9.Now connect R607 and plug it to mains, check the voltage (AC) in between 5 and 6 of the transformer T605. If “yes” the transformer is oscillating , now check the voltage between point c641(dc). If “No”then check this rectifier D641 and associated circuit .including R671,672,670,660,667,666. If “yes”the audio voltage is ok 10.Now check the voltage (AC) at point 7,8,9 of the transformer T605 . If yes then check voltage at point 5 of IC641 (9v regulator) to ground ,If “yes” check the pint 3-4 to ground which is about 9v(DC) .If no then suspect ic 641 to resistors R663,664,665 or D646 . 11. Now check the voltage(AC) at point 10 and 11 of T605 If “yes” then connect the diodes d615,644,643,645 . (THE ZENER DIODE D648 IS REMOVED) the voltage between c643 this is the main +ve voltage. If ‘ no”then suspect diodes If everything is” ok “then only connect the D648 , which normal case you don’t need this zener diode.connect the 60w bulb between B+ and –ve. 12. If everything ok connect to main board, after connect main board any problem suspect horizondal transistor,yoke,flyback transformer , fly back capacitor c509,c527,c511 ir damper diodes D502, 503 504 (ERC06-1SS). Note: Diode D602 can replace with 4 IN4004 or similar (Bridge) Diode D644,643,615,645( D2L20U0 ) can be replaceable with high efficency high voltage recifires. Diode D646 (D10sc4M) can replace with high efficiency low volgage full wave diodes Diode D641 is (RBA-1004B) can replace with high efficency low volgage bridge. IC641 is S!-3090CA is 9v regulator. IC 642 (NJM78MOS) is 5v regulator.

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