Sony HDCU-900 - Manual (Page 27)

1-17 (E)
HDCU-900 MM
1-10. Circuit Protective Elements
The positive characteristic thermistor (for power supply) functions as a circuit protective element on the
AT-141, DPR-163, RC-86, IF-789A/789P (HKCU-901), FC-83 (HKCU-903) and LC-41 (HKCU-904)
boards of the unit. The thermistor increases the internal resistance and limits the current flowing to the
circuits when an overcurrent flows or when the ambient temperature increases and the element reaches
the specified temperature. If the elements operates, turn off the main power and inspect the HDCU
internal circuit. After removing the cause of the equipment abnormality and the temperature of the
element decreases, turn on the power again and operate the unit correctly. It takes about 1 minute for the
elements to cool down after the main power is turned off.
Board Ref. No. Address Protective circuit/equipment
AT-141 THP800 A9 Circuit inside the board
THP801 B8
THP802 B4
THP901 G9 Circuit inside the board
THP902 F9
THP903 K1
THP901 H9 Circuit inside the board
THP902 G9
THP903 G8
THP904 L8
THP905 L8
THP906 M8
THP907 M8
RC-86 THP1 B9 Circuit inside the board
THP2 B9
IF-789A/789P THP701 A9 Circuit inside the board
(HKCU-901)
FC-83 (HKCU-903) THP821 B8 Circuit inside the board
LC-41 (HKCU-904) THP601 B8 Circuit inside the board
1-10. Circuit Protective Elements
DPR-163
(Board suffix: -11 through -14)
DPR-163
(Board suffix: -22 and later)