Problems Caused by Long Screws

Gabi Ra'anan
08-Jul-01

If you have problems which are related to the Local boards -please ensure that your problem is not because of the following reasons:

Local2 boards:
The screws (Dia. 8/32" - see photo below) that secure the Local box to the chassis should be no longer than 3/8".
Using longer screws may cause electrical shortage between conductors on the board inside and the metal box that contains it ( which is grounded through the machine chassis).
In one occasion that caused shortage of -12V on the Local board to the ground - the symptom was DRUM RUNAWAY.

secure the box to chassis

Local3 boards: The screws (10/32" -see photo below) that secure the Local box HOUSING to the chassis should be no longer than 3/8" - longer screws protrude into the housing, they may stand in the way of the Local box when you insert it into the housing and the connectors may be poorly connected to the Local3 motherboard.