Brother 1250, 1240 High-voltage power supply PCB / Engine PCB, Electrode helical spring / Chute

APPENDIX

PR99174

APPENDIX 23. DIFFERENCES BETWEEN OLD & NEW VERSIONS OF HVPS & ENGINE PCB

The high-voltage power supply PCB and engine PCB have been upgraded since the production in the middle of September, 1999 in order to improve print quality. In accordance with the change, the T/R electrode helical spring and plastic chute have been also changed.

This section describes the differences between the old and new versions of those parts so that the service technician can identify the old or new version at a glance.

High-voltage power supply PCB / Engine PCB

Check the pin number of the connector on one of the high-voltage power supply PCB and engine PCB, which connects those two PCBs. While the old version has 7 pins, the new version has 8 pins. The figure below indicates the connector on the Engine PCB.

Old version

	New version
7 pins	8 pins

Engine PCB

Fig. A- 16

T/R electrode helical spring / Chute

The size of the T/R electrode helical spring is different between the old and new versions. While the spring is assembled onto the big boss on the plastic chute for the old version, it is assembled onto much smaller boss on the chute for the new version. Note that the assembled position of the spring is also different.

Old version

New version

T/R electrode helical spring

Chute

Fig. A- 17

A-34