I read your solution. on my chirping problem.. I found the C920 but cannot find the IC 401.. is it possible you meant IC 501? the LA6324N Thanks in Advance
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It sounds like you may problems in the TV's circuits, but try resetting first by unplugging TV from power source. If no fix try these areas of concern:
1. SHUTDOWN CAN BE CAUSED BY NO VERTICAL DEFLECTION. SINCE THE VERTICAL CIRCUIT IS POWERED BY THE SWITCHED POWER SUPPLY THE UNIT MUST BE TURNED ON TO TROUBLESHOOT THE CIRCUIT. THIS CAN BE ACCOMPLISHED BY TEMPORARILY DISCONNECTING THE VERTICAL INPUT TO THE X-PROTECT CIRCUIT. ** TO PREVENT DAMAGE TO THE CRT'S YOU MUST UNPLUG THE CRT PCB'S. ** TO DEFEAT THE X-PROTECT CIRCUIT, UNSOLDER D4A1 LOCATED OFF THE COLLECTOR OF Q4A1. IF THE UNIT POWERS ON AT THIS POINT, YOU HAVE CONFIRMED A VERTICAL FAILURE AS THE CAUSE FOR SHUTDOWN. ** D4A1 MUST BE REINSTALLED IN CIRCUIT TO PREVENT CRT DAMAGE. ** 2.CHECK PIN 1 OF IC401 FOR 10.7VDC. IF LOW OR MISSING CHECK FOR SHORTED D4000 LOCATED OFF PIN 1. (PCB-MAIN) D4000 PART #264P487030 3. CHECK PIN 8 OF IC401 FOR 27.7VDC. IF MISSING CHECK FOR OPEN D955 AND L961 AT S1 TERMINAL OF T902. (PCB-POWER) D955 PART #264P102040 L961 PART #411P012010 4. CHECK FOR DEFECTIVE IC401. IC401 PART #272P239040, OR INSTALL PT# IC-401, THIS KIT CONTAINS CAPACITOR C920, D4000 AND IC401. BE SURE TO MOUNT C920 ON FOIL SIDE OF PCB. 5. EXCESSIVE 130V SUPPLY. CHECK C911 47 UFD 100 V AND C914 47 UFD 50 V, IN THE IC900 CIRCUIT.
Good Luck, big IRISH.
1. SHUTDOWN CAN BE CAUSED BY NO VERTICAL DEFLECTION. SINCE THE VERTICAL CIRCUIT IS POWERED BY THE SWITCHED POWER SUPPLY THE UNIT MUST BE TURNED ON TO TROUBLESHOOT THE CIRCUIT. THIS CAN BE ACCOMPLISHED BY TEMPORARILY DISCONNECTING THE VERTICAL INPUT TO THE X-PROTECT CIRCUIT. ** TO PREVENT DAMAGE TO THE CRT'S YOU MUST UNPLUG THE CRT PCB'S. ** TO DEFEAT THE X-PROTECT CIRCUIT, UNSOLDER D4A1 LOCATED OFF THE COLLECTOR OF Q4A1. IF THE UNIT POWERS ON AT THIS POINT, YOU HAVE CONFIRMED A VERTICAL FAILURE AS THE CAUSE FOR SHUTDOWN. ** D4A1 MUST BE REINSTALLED IN CIRCUIT TO PREVENT CRT DAMAGE. ** 2.CHECK PIN 1 OF IC401 FOR 10.7VDC. IF LOW OR MISSING CHECK FOR SHORTED D4000 LOCATED OFF PIN 1. (PCB-MAIN) D4000 PART #264P487030 3. CHECK PIN 8 OF IC401 FOR 27.7VDC. IF MISSING CHECK FOR OPEN D955 AND L961 AT S1 TERMINAL OF T902. (PCB-POWER) D955 PART #264P102040 L961 PART #411P012010 4. CHECK FOR DEFECTIVE IC401. IC401 PART #272P239040, OR INSTALL PT# IC-401, THIS KIT CONTAINS CAPACITOR C920, D4000 AND IC401. BE SURE TO MOUNT C920 ON FOIL SIDE OF PCB. 5. EXCESSIVE 130V SUPPLY. CHECK C911 47 UFD 100 V AND C914 47 UFD 50 V, IN THE IC900 CIRCUIT.
Good Luck, big IRISH.
This model is famous for capacitors being bad in the low voltage regulators on the signal board. Also has been known for cold solder connections in the power supply to the convergence IC. I don't have my notes at home but I belive that model only uses one IC for convergence, STK393-570. You cant see it from the back because of it being hidden by its heat sink.
Yes sir change IC 401 and dont forget to change C 920 also. This is a very common problem with this set. If you do not change the capacitor, the IC will fail again in a few weeks or days.
PS Dont forget to rate this.
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