2MByte SIMMs

As a result of field reports made about faulty systems being cured by "pressing SIMMs home" an investigation has been carried out on SIMM connections with the following findings.

In many cases the SIMM PCB length, including snap-offs, is greater than 89.25mm. The additional protrusion caused by the snap-off is of sufficient size to prevent the SIMMs being correctly inserted into the socket. Although electrical connection is made, the SIMMs are not being inserted far enough for the mechanical latching mechanism to lock them into place.

With the SIMMs not being fully locked into place, there is a distinct possibility of them being shaken loose in transit or by vibration after a period of use.

On systems where this is suspected to be causing problems the SIMMs should be exchanged or the snap-off excess should be shaved off.