However recent spares acquisitions brought 2 control units and one was removed from XL231 in May 1993 for probably bay servicing. The Form 731 was signed by Andy Price, the same Andy price that painted 'Lusty Lindy' on XL231 and who also painted the other Gulf War Victor 'Nose Art'.
The original unit was removed and within seconds of switching on the replacement it was obvious it was working in some capacity, the speed ran down to zero and the memory lamp went out after a while (it was stuck in memory on the old unit). Drift began to indicate and the neon row of lamps started to work. 100% better than the old unit. I then switched off because the cooling fans need to be checked on the Computer and Transmitter/Receiver trays before we go any further. These are located in the rear freight bay. However, all signs seem good!
Removed control unit