If main processor is inoperative, move main power switch to on (Figure 1-3), check input line voltage to
processor from battery. If reading is not between 25 arid 28 Vdc, check power source. If reading is between 25
and 28 Vdc go to step b.
Check output voltage to video monitor and keyboard. If reading is not between 25 and 28 Vdc, check fuse,
replace fuse as given in paragraph 4-6.3.1 or replace faulty printed circuit board as given in paragraph 4-6.3.2. If
main processor is not operative after repair, troubleshoot monitoring system as given In paragraphs 5 and 6 in
Section IX of the PMS II Maintenance Manual. If main processor still not operative, replace main processor as
given in paragraph 4-6.5.
4-6.3.1 Fuse replacement
5A fuse (Figure 3-2). Unscrew fuse holder and replace fuse.
2A fuses and 6.25A fuse (Figure 3-2). Remove and replace fuse(s) on printed circuit boards (power supply, input
or process and display). See Section VII of the PMS II Maintenance Manual for additional fuse information.
4-6.3.2 Printed circuit board replacement
The printed circuit board contains some components that are sensitive to static electricity and
therefore must be handled with caution.
Hold board (power supply, input or process and -display) only by the edges and do not touch individual
components or back of board when removing board
If board Is to be repaired, place board inside of protective bag supplied with board.
If board is to be reused, always lay board on a flat surface and on top of the protective bag supplied with
EPROM's may have to be replaced on process and display and input printed circuit boards.
See Section IX paragraph 2.0 in PMS II Maintenance Manual In Appendix B.
Hold board as given in Step a(1), when board is installed in main processor or being removed from
Always lay board on a flat surface and on top c)f the protective bag when board is out of bag.
4-6.4 Calibration. Calibrate PMS system as given in Section IV in PMS II Maintenance Manual in Appendix B.
Disconnect cable (C2) to keyboard.
Disconnect cable (C1) to video monitor
Disconnect cables (C5 and C6) to terminal boxes
Disconnect cable (13P13F) to main power switch.