Had a go of this, here. I might've been purposely trying to cause a malfunction.
Fun fact: I was on a school trip to Russia from April 6th to 13th 1986, coming home just two weeks before it all happened. Half a week in Leningrad (as it was at the time), then an overnight train to Moscow. Amazing holiday, beautiful country, and I'd love to go back one day, although not for a while, I guess.