Sorry but that was a mistake. This forum is full of posts from people who tried shotgun cleaning & adjustments, and caused more problems than they were originally trying to solve.
What to do instead: Slowly and carefully diagnose one problem at a time and then fix only that.

There should be a Player Unit disk (or similar). Check that out for good contact and adj.

Can you scan and post some relevant parts of the schematic?

I have a 1952 C.C. "Bowl-a-Ball" rebound ball bowler, but I never knew United
produced a ball bowler as early as 1951. I wouldn't mind knowing the title of
your machine..
Anyways, like mentioned, you'll want to check the "Player-Step-Up" unit, along
with the "Coin Unit". This is especially important for the "Player Reset" Relay to
energize at the proper time..
For the Player Step Up, my guess would be to check the switches in the "Player
Reset" Relay, most likely a make-break switch. The switches in the "Score Control"
Relay, and also the switches that run off the Score Motor's cam. Can't help on
which one, but rechecking them all wouldn't be a bad idea..
Before adjusting the switches, it's always a good idea to tighten' up the switch
stack screws first..
Any chance of sending a pic or two of your machine?

Hello sepins

I see that you downvoted my post but didn't post anything yourself. Do you have any constructive or better advice for EM novices than I had?

HowardR

https://pinside.com/pinball/forum/topic/1951-united-ball-bowler-player-up-#post-4478755

Why beat the guy up for having issues.

Post some help if You're capable.

I'm not capable but You didn't help Him.

Mopar very nice of You to take the time to try and help!

Come on Hibler post some wisdom!

They Didn't. 1956 was the first year United made a ball bowler.

Yup, and I'm pretty darn sure that it's a Bowling Alley that is being dealt with here..

I hear that you interpret what I said as beating him up. I was actually trying to save him and others from causing even more problems than he already did. And I did post some help about how to think about working on his game.

If you don't find my posts helpful, no problem there. I have a way of working on EMs that works and many (maybe not all) here on pinside find helpful. So I'm not really planning to change what I do.

Bottom line for me is 'to each his own' and best of luck to you, sepins

When I brought my United Bowling Alley back from the dead I used the TOP #8 dvd http://www.pinrepair.com/top/top8.htm it was a great source and a must have if you are taking on a bowler.

I would say this is always sound advice.

WTF-congrats on finding the problem! Here is some good reading about schematics: http://www.pinrepair.com/em/index3.htm#schematic