6.3.8.
SRAM AND RTC BACKUP CIRCUIT
1. Function
This unit has a lithium battery (BATT) which works for the SRAM (IC504) and Real Time Clock IC (RTC: inside IC501).
The user parameters for autodial numbers, the system setup data and others are stored in the SRAM (IC504).
The RTC continues to work, backed up by a lithium battery even when the power switch is OFF.
2. SRAM (IC504) Backup Circuit Operation
When the power switch is turned ON, power is supplied through pin 12 of IC501 to the SRAM (IC504). At this time, the voltage
at pin 28 of the SRAM is 5V. When the power switch is turned OFF, the BATT supplies power to the SRAM through J501, R556
and D508. The voltage at pin 28 of the SRAM is about +2.5V. When the power switch is OFF and the voltage of +5V decreases,
the voltage detect IC (IC509) outputs "Low " level and the IC501 outputs the reset signal. Pin 28 of the SRAM becomes roughly
the same voltage as the battery voltage. At this point, pin 20 (CS) of IC504 becomes high level, causing the SRAM to go into
the backup mode, in which the power consumption is lower.
3. RTC Inside (IC501) Backup Circuit Operation
When the power switch is turned ON, power is supplied through DA501 to the RTC (inside IC501). At this time, the voltage at
pin 7 of the IC501 is +3.3V. When the power switch is turned OFF, the BATT supplies power to RTC through DA501. The
voltage at pin 7 of IC501 is about +2.5V. When the power switch is OFF and the voltage of +3.3V decreases, pin 7 of RTC
(IC501) becomes roughly the same voltage as the battery voltage. RTC goes into the backup mode, in which the power
consumption is lower.
129
KX-FP101AL
Summary of Contents for KX-FP101AL
Page 7: ...1 11 ITU T Test Chart Actual size 7 KX FP101AL ...
Page 9: ...1 12 2 CONTROL PANEL 9 KX FP101AL ...
Page 18: ...1 14 12 REPLACING THE FILM CARTRIDGE 18 KX FP101AL ...
Page 19: ...19 KX FP101AL ...
Page 29: ...2 3 3 TROUBLESHOOTING ITEMS TABLE 29 KX FP101AL ...
Page 30: ...2 3 3 1 Simple Check List 30 KX FP101AL ...
Page 32: ...2 Document JAM 32 KX FP101AL ...
Page 36: ...6 Paper JAM 7 Multiple feed and skew 36 KX FP101AL ...
Page 39: ...Fig C 12 A blank page is received 39 KX FP101AL ...
Page 43: ...2 3 3 3 1 Defective facsimile section 1 Transmit problem 43 KX FP101AL ...
Page 50: ...50 KX FP101AL ...
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Page 57: ...57 KX FP101AL ...
Page 65: ...I O and Pin No Diagram 65 KX FP101AL ...
Page 67: ...67 KX FP101AL ...
Page 68: ...68 KX FP101AL ...
Page 69: ...2 3 3 4 2 Check the Status of the Digital Board 69 KX FP101AL ...
Page 73: ...2 Troubleshooting Flow Chart 73 KX FP101AL ...
Page 75: ...2 3 3 7 Operation Panel Section 1 No key operation 2 No LCD indication 75 KX FP101AL ...
Page 78: ...2 3 3 9 CIS Contact Image Sensor Section Refer to 6 4 4 SCANNING BLOCK 78 KX FP101AL ...
Page 79: ...79 KX FP101AL ...
Page 80: ...2 3 3 10 Thermal Head Section Refer to 6 4 3 THERMAL HEAD 80 KX FP101AL ...
Page 93: ...2 4 7 3 PRINTOUT EXAMPLE 93 KX FP101AL ...
Page 94: ...94 KX FP101AL ...
Page 97: ...2 5 3 PRINT TEST PATTERN 1 Platen roller Reference pattern 97 KX FP101AL ...
Page 98: ...2 Left margin Top margin Reference pattern 98 KX FP101AL ...
Page 99: ...3 Thermal head 1 dot Reference pattern 99 KX FP101AL ...
Page 122: ...6 3 2 MEMORY MAP 122 KX FP101AL ...
Page 134: ...134 KX FP101AL ...
Page 144: ...6 4 6 3 2 Transmitting documents 6 4 6 3 3 Receiving FAX 144 KX FP101AL ...
Page 145: ...6 4 6 3 4 Copying 145 KX FP101AL ...
Page 163: ...163 KX FP101AL ...
Page 171: ...7 1 MEMO 171 KX FP101AL ...
Page 172: ...172 KX FP101AL ...
Page 176: ...9 1 MEMO KX FP101AL 176 ...
Page 180: ...11 1 MEMO KX FP101AL 180 ...
Page 182: ...12 1 MEMO KX FP101AL 182 ...
Page 184: ...13 1 MEMO KX FP101AL 184 ...
Page 186: ...14 1 MEMO KX FP101AL 186 ...
Page 188: ...15 1 MEMO KX FP101AL 188 ...
Page 189: ...16 TERMINAL GUIDE OF THE IC S TRANSISTORS AND DIODES 189 KX FP101AL ...
Page 190: ...17 FIXTURES AND TOOLS 190 KX FP101AL ...
Page 192: ...18 2 UPPER CABINET SECTION 192 KX FP101AL ...
Page 193: ...18 2 1 PICK UP BASE SECTION 193 KX FP101AL ...
Page 194: ...18 3 LOWER P C B SECTION 194 KX FP101AL ...
Page 195: ...18 4 MOTOR SECTION 195 KX FP101AL ...
Page 196: ...18 5 ACTUAL SIZE OF SCREWS AND WASHER 196 KX FP101AL ...
Page 197: ...19 ACCESSORIES AND PACKING MATERIALS 197 KX FP101AL ...