Volvo Repair: Volvo 850 Speedometer & Tripmeter, volvo 850, rm1

Question
I drive a 1996 model of 850 SW (T5) - Asian model. While driving home from work yesternight, i noticed my speedometer and my tripmeter weren't working. I called a friend who owns a similar car and he gave me a tip on the road. While driving and the car in motion, crank the ignition just a bit, until all the lights go out. Don't go all the way to crank the ignition - just a little small twitch. THen release the ignition immediately. VOILA! All the lights came back, together with the Speedo and Trip meters. I asked him what was the problem - he simply said, "Your keys are WORN. Fork out RM40 for a duplicate, and ask them to make the edges just a tad sharper." ... HUH ... ? Erg. Is this a valid factor? It must be cause I must have tried it a dozen times, as whenever the car comes to a stop at junctions, the meters go dead again, and after carefully performing the acts, the meters go wonders again. But I don't understand how the key could affect the meters. Is there a better alternative to this (aside from forking out RM1,500 for a new set of ignition and key system)? Kindly explain, sir. Thanks.

Answer
The ridging on the key is used only to physically turn the switch, and locks.  It may be coming back because when you turn the key to the last position real quick it temporarily cuts power to the display and when it goes back it gets power again and effectively gives the display a reboot like your computer.  The key is most likely not the cause of you problem even though playing with it did correct your problem.  If the keys were significantly worn it wouldn't turn in the switch.  If yours does then there is nothing wrong with the cut of the key.  The problem is either in the computer that provides power/signal for the speedo display or the gauge itself.  It would have to be electically troubleshooted to be certain which was to blame.  Hope that helps.

James