■Troubleshooting
No Power
The possible causes of No Power are listed below. Please check following and refer to power supply and protection cir- cuits diagram in the figure opposite.
1. Stop the operation of power supply circuit due to detection of abnormality.
-Detected the abnormality on the secondary power supply lines.
Power failure detection diodes detect an abnormal volt- age on the power supply. Check the shortage of second- ary circuits, ICs, condensers, etc.
-Detected the operation stop of cooling fans.
Power failure detection diodes detect the fan operation stop. Check Fans FN901, FN902, FN903, FN904, FN905 and FN906
Check fan's power supply lines and detection diodes and transistors D69A, D69B, D69C and Q69A
- Detected the abnormal temperature rise inside the projec- tor.
Temperature sensor ICs detect abnormal temperature. Check peripheral circuits and sensor ICs IC4881 and IC2881.
Thermal switch (TSW611) detects abnormal temperature. Check peripheral circuits and TSW611.
TSW611.................... open in normal
TSW611 shorts when the peripheral temperature is over 90°C.
Thermal switch (SW902) detects abnormal temperature. Check peripheral circuits and SW902.
SW902...................... short in normal
SW902 opens when peripheral temperature is over 100°C.
- Detected the abnormality on the lamp ballast unit.
The lamp ballast unit outputs error signal (LAMP_ERR) to pin 47 of IC801.
LAMP_ERR .............. High in abnormal
-Detected the over load/over voltage on power supply circuit. Feedback circuits detect over load or over voltages. Check PC641, PC642 and peripheral circuits.
-Operated the mechanical protect on the Interlock switch (SW904). Check lamp cover fixed correctly.
-Fuse (F601) open.
-Abnormality on lamp ballast drive signal (BALLAST_AC). BALLAST_AC signal is output from pin 39 of IC801 and sent to pin 11 of IC1881, and output from pin 9 by the name of BALLAST_AC1 signal. BALLAST_SW1 signal drives the lamp ballast unit.
Check BALLAST_AC and BALLAST_AC1 signals and lamp ballast unit.
-Abnormality on fan drive signal (FAN DRIVE).
FAN DRIVE signal is output from pin 41 of IC801 and sent to pin 15 of IC1881, and output from pin 5 by the name of FAN DRIVE1 signal. FAN DRIVE1 signal drives fan supply voltages (12V/12V1) on the power board.
FAN DRIVE/
FAN DRIVE1 .............. High in power on
Check FAN DRIVE/FAN DRIVE1 signals, 12V regulator circuits IC681, Q681, Q682, Q66A, IC671, Q671, Q672 and peripheral circuits.
-Abnormality on power drive signal (LAMP_BST_SW). LAMP_BST_SW signal is output from pin 82 of IC801 and sent to pin 2 of IC1871, and output from pin 18 by the name of LAMP_BST_SW1 signal. LAMP_BST_SW1 signal drives the power factor control IC on the P.F. board through the Power board.
LAMP_BST_SW/
LAMP_BST_SW1 ............ High in power on Check LAMP_BST_SW and LAMP_BST_SW1 signal,
3.Abnormality occurs on the power circuit.
- Abnormality on power primary circuit
Check Line filters, L601, L602, D614, L611, IC631, D632, etc.
- Abnormality on power secondary circuit Check D651, D652, D653, IC651, etc.
2.Abnormality occurs on drive signals for power or lamp circuit.
-Abnormality on power starter signals (POWER, 5V_SW). POWER signal is output from pin 1 of IC801 and sent to pin 17 of IC1881, and output from pin 3 by the name of 5V_SW signal. 5V_SW signal drives 15.5V and 9VMCI power supply circuits on the power board.
POWER/5V_SW ............ High in power on
Check POWER and 5V_SW signals, 9V regulator circuit Q65A, Q65B, Q65C, IC65A and peripheral circuit, 15.5V switch circuit Q661, Q662 and peripheral circuit on the Power Board.
