Panasonic KX-P2123 Service Manual page 28

8.2.6 Head Drive Block
This block consists of QA400-408 and 1C7-8. QA400-405 control each pin and QA406-408 control the power
supplied to the printhead.
The CPU sends the data H1-H24 of IC6 (Gate Array). Then the CPU also sets printing pulse and triggers TO4
and TO5 terminal of IC1. During this time, the head pin solenoids are fired by QA400-405 according to the
data. The power supplied to the printhead is controlled by IC6 through QA406-408.
A thermistor is attached in the printhead and is used for detecting overheat of printhead.
Timing Chart
Trigger Pulse
HDCO1, HDCE1 | I
HDCO2, HDCE2 |
Print Pulse | | | |
oe HDCO6, HDCE6 | ial | | |
fa |
| | Print Pulse | | | |
| H11, H13, H12, H14 —| |
|
Ht,H23,,H2,H2d | UILCLL CECUdSt~=<"<t='s*'CN TTT"
| TS: Sel
H9,H15,H10,H16 |
i
|
|__|
Td
Print Pulse Time Printhead
about 245 sec | about 480 u sec
about 245 p sec
8-12
20.0 + 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 = 1 ohms
20.0 + 1 ohms
20.0 £ 1 ohms
20.0 £1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 £ 1 ohms
20.0 £1 ohms
20.0 t 1 ohms
20.0 + 1 ohms
20.0 + 1 ohms
20.0 £1 ohms
20.0 = 1 ohms
Less than
50K £ 5 Kohms
(at 25C)