2002 Mitsubishi Galant will not start

Hi all… I have a 2002 Mitsubishi Galant GTZ. On Friday morning, I drove to the bank, no problem. Parked the car (in the shad on a very slight downward incline) until Saturday afternoon. When I tried to start it, the engine barely tried to turn over, but did not. I assumed the battery was dead even though all the interior electronics worked. On Sunday, a friend helped me jump the car, but it did not help. This time, the engine did not even attempt to turn over - no audible click or any other sound from the engine. All electronics still work (interior/exterior lights, radio, windows, AC…)



I spoke to a Mitsubishi service tech who said he did not believe it was the Starter but rather the ignition switch…



I’ve tried banging on the starter with a hammer, starting the car in Neutral, (it is an automatic tho), and jumping it off 2 different cars with 2 different sets of cables.



Does anyone have any other ideas as to what is going on? I’d like to fix this myself if at all possible, but I don’t think I can even properly diagnose the problem.



Thanks in advance!!

-jim

Sorry… a little more info… I just had the oil changed to a high mileage oil at good year about 70 miles ago. There are approximately 85,000 miles on the car.

At one point, it was recommended that I change the spark plugs, but I was told it would be like $1000 b/c they had to remove the engine… The serpentine belt is also a candidate for replacement. Could either of these things be my problem?