Where do you live? If you are near So Cal you can bring it to my place and we can fix it together so you can get some hands on experience.
Sounds like some common problems,fairly minor issues that should be easy to fix. Then it probably needs a good cleaning and wax.

If you lack any skills like soldering or using a meter, Youtube has lots of short how to videos.

Auto Launcher - check coil sleeve for dirt, wear, cracks, replace. Clean plunger. Check for loose or worn parts.

Flippers - I'd rebuild and start fresh. New coil sleeve, new coil stop, new plunger assembly.

Ball getting back to playfield - check for dirty or worn parts. Make sure switch in there is working. You game has a switch test - go into it and hit some switches so you learn what happens and what reports on DMD.

vid1900 has a good write up here on Pinside to rebuild flippers. You can search posts on cleaning and waxing your playfield. If you order any parts, I'd add some new balls for your game too.

Leveling game - Todd Andersen has some useful articles on Pinball News :

http://www.pinballnews.com/learn/level/index.html
http://www.pinballnews.com/learn/iphone2/index.html
http://www.pinballnews.com/learn/iphone/index.html

And when you run into a problem. Don't get frustrated. Post here, pictures too if needed. And you'll likely get some help.

Welcome my friend, to the wonderful world of pinball.

LTG : )

Given that many of your coils are weak, check your voltage at the wall.

LTG What is proper voltage at the coils on Striker Xtreme? 50v?

As LTG says, sounds like you have some wear to the flipper / plunger mechs which cause drag and weakens flippers, ball launch, etc. Relatively easy to repair/rebuild, and will give you tremendous satisfaction.

A great starting point for DIY repair is Clay Harrell's This Old Pinball DVD's. i think they are less than 10 bucks each. He has 2 dvd's that pertain to modern games (1991 and up). Spending an hour watching will help you learn a ton. I have found them to be much better than most videos on youtube.

http://www.pinrepair.com/top/

Is it possible with this machine to set 'coil pulse power' like some other machines ?

adj31.jpg

I'd check the manual, high voltage ones 50V ( might be higher not under load ) I don't know if Stern used and low power coils in that game.

I'd carefully check the wall outlet AC and then check what the game is wired for. And example of wall outlet 100AC and game wired for 120AC will give you weak coils.

Don't wire the game lower to make things stronger. Just try and match the voltages.

LTG : )

If pinside was a dating site, the first reponse the OP just got to his first ad was a request for him to move in with you

http://pinballlife.com/

Im so lonely...

Ill come visit you with my broken games.........

Huh? Do you mean your panel? That shouldn’t affect anything. You could have shot caps in ac/dc conversion or bad bridge rectifier(s). Just need to measure voltage at coils.

Mushroomed plungers, dirty coil sleeves, mechs physically dragging on something .. these all can cause weaker flippers or up/out kicks.

I always rebuild flippers when I get a used game out of habit. Good starting point as part of shop out, along with new rubbers and a deep clean.

Auto launch could be binding on something or striking something, causing it to lose power. For example, on my sopranos it occasionally hits part of the trough switch which results in about 1/2 power.

You're always welcome at my place Art, with or without broken games...

http://www.pinwiki.com/wiki/

Amps and volts are very different. You MUST proceed safely when testing electrical items. You should educate yourself before further troubleshooting.
You don't want to electrocute anyone (including yourself) or burn down your house.

Watch some videos and you'll probably gain enough knowledge to be safe.

On the auto plunger -- sometimes the shooter rod (and it's rubber piece) hold the ball up higher than it should which means the auto launcher mech doesn't hit the ball hard enough. Ran into this with my Stern Simpsons Pinball Party game. Research showed other Stern games suffer from this as well.

Before you worry about voltage, I would start with the simple solution which is rebuilding the flippers, auto plunger and VUK (vertical up kicker). All 4 of these are basically the same thing. You won't find a handy VUK or Auto-plunger rebuild kit like you will for the flippers, but it's mostly the same parts. Coil stop, sleeve and plunger. My guess is that they have never been changed and are badly mushroomed causing them to be underpowered.

There's a good joke in here if someone wants to work for it...

https://en.wikipedia.org/wiki/U-Haul_lesbian

Welcome to pinside. Where in Massachusetts are you?

If you want I can face time with you to help you out with the basics . If it will help . Just shoot me a pm if your interested .