CTC210_211_ScanB+_Supply_Trblshoot_A2D9706F72E8182CE0339DFEEACC182C_25.pdf part of RCA D52130 RCA_CTC210-211_01.rar, Large File 6 pare RAR Folder containing: Flow Charts, Tech Tips, Trouble Shooting Manuals, Updates, Module Training, and Symptom Fixes text manual preview

Text preview for : CTC210_211_ScanB+_Supply_Trblshoot_A2D9706F72E8182CE0339DFEEACC182C_25.pdf part of RCA D52130 Large File 6 pare RAR Folder containing: Flow Charts, Tech Tips, Trouble Shooting Manuals, Updates, Module Training, and Symptom Fixes

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Troubleshooting Scan B+ Supply (Q14800)
1. Obtain latest Chipper Check failure code and check circuit areas accordingly. IMPORTANT: DO NOT reinitialize the EEPROM! 2. Remove & secure CRT CBA. 3. Disable Horizontal Drive Q14451 by removing L14454 (removes B+ from Q14451). 4. Disable Scan Loss Detect on Main CBA by shorting B-E of Q14813. 5. Unsolder pin 18 of J14102 (defeats Scan Loss Detect from deflection SIP CBA). 6. Turn instrument on and measure Scan B+ voltage (TP14801); should be between 130-145VDC. 7. If Scan B+ = 130-145VDC (2H Scan B+ supply is operational), check collector circuit of Q14451 and yoke return circuitry. 8. If horizontal collector circuit checks OK, check for horizontal drive from Deflection SIP CBA. 9. Check Q14805 and associated components. 10. Verify that Q14811 is turned off (always OFF except during scan loss shutdown). 11. If Q14805 & Q14811 checks OK, go to next step. 12. If Scan B+ (TP14801) is below 130, check 2H Scan B+ generator and Regulator circuits (Q14800/801/802/804) if suspect replace all active devices.