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27. Grand Wega Lamp Control
Table 27-1 - How the Main Micro Determines if the Lamp or Circuitry is Bad
Condition
PRT (Protect)
CN1908/pin 3
Visual Arcing at G1/ RF at CN1908/pin 12
Normal
Low (0Vdc)
None
Lamp LED blinks Continuously (HV OK.
Lamp bad)
High (5Vdc)
Yes at power ON and repeats every 5
seconds later until TV shutdown (3 mins.).
Standby LED blinks 5 times (No HV,
Power Block, PS fuses, or M board bad)
High (5Vdc)
None
Defect – The Standby LED blinks five times – At power ON when the Power block is instructed to turn ON (HIGH
@ white wire to Power Block / CN1908/pin 1), but no current is drawn (HIGH at end gray wire / CN1908/pin 3),
the lamp or the Power Block is defective. To determine which is defective, the antenna signal (explained in the
last paragraph) is used by the Main Micro only when the PRT line (CN1908/pin 3) remains HIGH (no lamp
current).
During this defect, PRT = HIGH forces the Main Micro IC9004 to request information about the presence of HV
via serial data from Lamp Control IC1952. If RF (HV) is not detected, the Main Micro keeps the audio and video
muted, blinks the Standby LED blink five times and shuts down the TV in three minutes.
HV antenna positioning
After repairs, reposition the black HV antenna near one of the HV leads as shown in Figure 27-2. If it is not
positioned as shown, the LAMP LED will NOT flash during a lamp defect.
FIGURE 27-2 - HV ANTENNA POSITION
HV
ANT
WIRE