Sony PFM-42B2, Service Manual

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3-3
PFM-42B2/42B2E
3-2. Self Diagnosis Function
3-2-1. Outline
The PFM-42B2/B2E has the self diagnosis function using
A/D converter to detect the power supply analog voltages,
8 channels of temperature sensor, fan operations, power
unit temperature, DC voltage status, and to check the
EEPROM and the watch register. When any abnormality
occurs or defect is detected, the standby indicator on the
control panel flashes and the detected data is displayed on
the service menu [STATUS/TEST] block. If the abnormal
status exceeds the allowable limit, the PFM-42B2/B2E is
forced to shut down.
The detection items are shown as follows.
1. Increase of temperature at the I/O block on top of the
panel is detected. Shut down of machine.
2. Increase of temperature at the center in the top of the
panel is detected. Shut down of machine.
3. Increase of temperature at the XSUS on top of the
panel is detected. Shut down of machine.
4. Temperature at the left side of the panel is detected.
5. Detection of fan stop and that of drive circuit failure.
* Two fans at the bottom of the panel and the two fans
for power supply circuit. One fan in the I/O block.
6. Detection of temperature rise in the power supply
block.
7. Shut down when the 5 V for internal digital circuit has
abnormality.
8. Detection of failure of the EEPROM.
9. Detection of abnormality in communication with scan
converter.
10. Detection of failure in the ON/OFF control of power
supply.
11. Detection of decreased backup power supply voltage
for watch and detection of abnormality in oscillator.
12. Detection of PDP failure using the combination of the
voltage detection and shut down of the machine.
3-2-2. Criteria for Judgment of Abnormality
1. Increase of temperature at the top of the I/O block in
the top of the panel is detected and shut down of the
machine.
(Name of this function on the service menu :
TEMPERATURE - I/O BLOCK TOP)
The normal operating range is up to 79
°
C.
Warning of high temperature when 80
°
C or higher.
Shut down at the temperature of 85
°
C or higher .
2. Increase of temperature at the center in the top of the
panel is detected and shut down of the machine.
(Name of this function on the service menu :
TEMPERATURE - CENTER)
The normal operating range is up to 74
°
C.
Warning of high temperature when 75
°
C or higher.
Shut down at the temperature of 80
°
C or higher .
3. Increase of temperature at the rear of the PDP and DC-
DC converter block is detected.
(Name of this function on the service menu :
TEMPERATURE - DD CON TOP)
The normal operating range is up to 84
°
C.
Warning of high temperature when 85
°
C or higher .
Shut down at the temperature of 90
°
C or higher.
4. Detection of at the left side of panel temperature
(Name of this function on the service menu :
TEMPERATURE - PANEL SIDE)
Occurrence of abnormality and fault is judged solely
from the internal temperature of the PFM-42B2/B2E.
Measurement of the ambient temperature aims mainly
at the confirmation of the operating environment.
Therefore, there is no chance to indicate this warning
message.
Warning of high temperature at 85
°
C or higher.