Having never really learnt what the various buttons do that control my Stack instruments I ended up pressing quite a few to reset thye trip after filling up with petrol. Sometime later I noticed that the Aces change up lights didn't seem to be working as they should: I had the green one lit up but when I passed 5,000rpm this went out and nothing else came on! So I pressed a few more buttons and, amoungst other things, ended up altering the brightness settings of the c/up lights but still no joy when they came off the test setting.