First, have the alternater checked at a parts house (most don't charge anything for this service) Just because the volt/amp guage gives a normal reading it can not always be trusted. You can buy an analysis computer that plugs in under your dash for about $50 and it will give you the reason it won't start. Or you can pay a mechanic.
If all the gauges jumped up and then down again it's probably the same thing that happened to my Mazda MPV van. The brain (computer) went out in it. Try to find a used one because it'll run you about $1000-$2000 for a new one.
when you turn the key on does the check engine light come on and then go off or does it not come on at all??..if it does not come on at all it sounds like a computer problem..if it does come on and off you could have an ignition module problem,(pick up coil or coil)....have you checked fuses??..electrical problems are sometimes the worst to try and find the cause...good luck