Work Day September 19

A tracker ball problem that has been around for a while was at last resolved today. It was a fault that we have lived but now needed fixing especially as it caused a problem last Saturday when demonstrating a jamming target. The tracker ball fault manifested itself when the simulator was switched on, it worked in azimuth for a while then stopped working completely. It was found that the +5V on the 8 port interface panel, rear of the I/O rack, was only +3.8V at the tracker ball encoder interface. Neil persisted with the fault finding and found that 1.2V was being dropped in the 8 port interface by a wire connecting the interface isolating switch on the panel to the tag strip that feeds +5V to the connectors for the console keyboards and tracker ball. The wire was bypassed to prove the fault. The result, the tracker ball worked perfectly. On occasions the Tech Sup keyboard also failed to work, that too is now also fixed. The suspected problem with the 8 port interface panel was oxidized crimp on the wire. We tested our spare 8 port interface unit which also proved to be U/S with no tracker ball control whatsoever. Taking both units home to repair.

Established that the CHARGE and display problems are 100% due to poor mains; doubly confirmed by running on a generator.

So today we can say that we switch on, the simulator boots, and runs perfectly – every time we power on.

Three years and two months after
we pulled the LCP out of the
long grass and nettles
we can say we are there – we are operational!

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