Overall System Description; Protection Circuits Functional Description; Lamp Error (Continuous Lamp Red Led Flash); Temperature Error (2X Red Power Led Flash Pattern) - Sony KDS-50A2000 Training Manual

Overall System Description

Reference Figure 5-1
The protection circuits (aka. Self-diagnostics routines) for the 2005 SXRD
monitor the following circuits and conditions in and around the TV for
abnormalities. If a failure occurs the Red Power LED on the front panel
will flash a unique pattern depending on the failure that occurred.
• Lamp Protect (Lamp Red LED Continuous Flash Pattern)
• External Temperature (2X Red Power LED Flash Pattern)
• Internal Temperature (2X Red Power LED Flash Pattern)
• Lamp Temperature (2X Red Power LED Flash Pattern)
• Lamp Door (3X Red Power LED Flash Pattern)
• Fan Error (4X Red Power LED Flash Pattern)
• Lamp High Voltage (5X Red Power LED Flash Pattern)
• Power Supply (6X Red Power LED Flash Pattern)
• Audio Output (7X Red Power LED Flash Pattern)
• Power OVP (8X Red Power LED Flash Pattern)
• Communications Error (9X Red Power LED Flash Pattern)
The Display Engine (DE) and TV (BE) microprocessors monitor all
protection circuits. The Protection Mode system employs nine unique
RED Power LED flash patterns to identify one of the circuit failures listed in
the previous bullet list. Notice that in some cases the same flash pattern
will occur for different failures, in these cases, you will apply further
troubleshooting procedures to identify the exact area of the failure.
TVP-23

Protection Circuits Functional Description

Lamp Error (Continuous Lamp Red LED Flash)

A current sensing circuit mounted on the Lamp Driver board (or Lamp
Power Supply Block) monitors the current drawn by the Lamp. As the
lamp ages the current it draws gradually decreases, and once it falls
below a predetermine threshold or stops completely the protection circuit
detects a defective Lamp. The TV will shutdown and the Lamp LED
flashes continuously.

Temperature Error (2X Red Power LED Flash Pattern)

The temperature error protection circuit monitors three areas for an
excessive temperature conditions.
The S1-Borad (LM75 Temperature Detect IC) monitors the local ambient
room temperature. The DE microprocessor regularly queries IC3150 on
the S1-Board over the I2C bus for temperature information. The threshold
is set to approximately 47 degrees Celsius. The S1-Board is located in
the lower right rear corner of the unit (mounted on the PCD chassis shield)
when looking at the unit from the rear.
The S2-Board (LM75 Temperature Detect IC) monitors the temperature
near the lamp. The DE microprocessor regularly queries IC3200 on the
S1-Board over the I2C bus for temperature information. The threshold is
set to approximately 70 degrees Celsius, and is located in the lower left
front corner of the unit on the top of the Lamp housing when looking from
the unit from the rear.
There is also a LM75 mount on the C-board, which monitors SXRD panel
area temperature. The DE microprocessor regularly queries IC2000 on
the C-Board over the I2C bus for temperature information. The threshold
is set to approximately 90 degrees Celsius, and is located on the C-board
atop the Optical Block. The C-board and Optical Block come from Sony
Parts Dept. as an assembly.
When any one of the areas describe goes above the indicated temperature
5. Protection Circuits
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