1-14
T4900CT
1.7
Power Supply
The power supply supplies five kinds of voltages to the T4900CT system board. The
T4900CT power supply has one microprocessor and it operates at 500 KHz (power off) or 20
MHz (power on). It contains the following functions:
1.
Determines if the AC adapter or battery is connected to the computer.
2.
Detects DC output and circuit malfunctions.
3.
Controls the speaker and the brightness.
4.
Controls the Battery capacity icon, Power on icon, and AC adapter icon on the
status indicator panel.
5.
Turns the battery charging system on and off and detects a fully charged battery.
6.
Determines if the power can be turned on and off.
7.
Provides more accurate detection of a low battery.
8.
Calculates the remaining battery capacity.
The power supply output rating is specified in table 1-5.
Table 1-5 Power supply board output rating
DC
Regulation
Maximum
Use for
Name
voltage
tolerance
current
Ripple
(V)
(%)
(mA)
(mV)
System logic, FDD, HDD
VCC
+5
±5
2,200
100
RS-232C, Flash ROM
12V
+12
±5
120
240
Display
DSPV
+9.5 to +23
–
4.02 W
–
RAM, CPU
B3V
+3.3
±5
2,200
60
RS-232C
M12V
–7 to –12.6
–
10
–
Summary of Contents for T-Series T4900CT
Page 20: ...T4900CT 2 3 Figure 2 1 Troubleshooting flowchart 1 2 ...
Page 176: ...B 2 T4900CT Figure B 2 Upper system board back ...
Page 178: ...B 4 T4900CT B 2 Lower System Board Figure B 3 Lower system board front ...
Page 179: ...T4900CT B 5 Figure B 4 Lower system board back ...
Page 199: ...T4900CT D 1 Appendix D USA Display Codes Table D 1 USA display codes ...