weak upkicker

Went back to repair the Dirty Harry from hell..
it's a game on location where a lot of kids come, the machine isn't in the best condition, and many kids flipping the flippers all the time... well, kids can break anything. really, anything.

If you don't believe me, take a look at this.. on two popbumpers the whole assembly was broken. On both rings, both screws/nuts had just broken off from the popbumper ring, and the metal and bakelite piece had also broken, parts were in the cabinet..

First problem was a wire broken off from the upkicker coil that brings the pinballs onto the ramp of the gun. All 4 pinballs were stuck in there..

Next problem was a melted flipper coil, replaced it with another, the flippers work fine. Adjusted the eos switches so they close halfway the stroke, but probably the kids will melt this new coil too.. just put kids for a few hours behind a pinball machine and let them flip all the time so the coils don't get time to cool off..

Next problem, a weak upkicker in the back. Disassembled the part and noticed why - part of the plunger that kicks the ball up the ramp had broken off. In the photo you see how little was left when with the plunger was raised, only about half a centimeter that extends the coil and tries to kick the ball in the air. Normally this part is 1,5 to 2 centimeter, so the pinball gets a good kick in the air.

I didn't have a replacement upkicker plunger with me, so this was a bit of a problem.
Tested it, but the pinball really didn't have enough power to get onto the ramp. This was a problem as pinballs get stuck there, or the coil can overheat or a fuse blow because the pinball machine continues to fire the coil over and over again in an attempt to kick out the pinball.

So, being creative was the only solution.. had to get this game playable, at least for a few days, until I could come back with the correct plunger.
Real operators would use wood screws but I don't want to damage a playfield :)
So wire straps were the best thing to use.. I just blocked the entrance so the ball couldn't get stuck.

Played a few games and it seems fine.
I do wonder how long it'll last.. not sure how strong these are because the flippers do kick the pinball quite powerful into them.
They're quite fun actually as the pinball is returned VERY fast, sort of a kicker on the latest Stern machines (like Iron Man) that also catapult the pinball back to the flippers, only this is my lowcost version ;-)

And this is not the only feature that's blocked on this game btw..

Another scoop had been blocked with clear packing tape, as pinballs got stuck there in the past.
Not the best solution, but hey, if it works for them, it works for me. At least that's one place where the pinballs won't get stuck anymore, so kids can continue playing pinball..

Badly soldered BR3 caused weak coils

Repaired a WPC pinball machine this week. Fuse F112 on the powerdriver board always blew, because BR3 had shorted.

Replaced BR3 with a new bridge rectifier. Worked quickly in less than ideal conditions (dark environment, above the playfield, ..).
Put the powerdriverboard back into the game, played a game to test everything.
I noticed some coils were weak: the automatic ball launch could barely get the ball onto the playfield, an upkicker also could barely kick the ball high enough so it got onto a ramp, sometimes it fell back down into the kicker..
Weird ?!

What really was strange was that the behavior wasn't consistent. The ball wouldn't get launched onto the playfield (just couldn't make the ramp) and rolled back in the shooter lane.. and a second kick of the coil would kick it hard enough and then it would end up nicely at the back of the playfield. The upkicker would try one or two times and then the pinball did make it correct.

Time to check everything I changed and parts involved.
The bridge rectifier was the correct type. Checked the new fuse I had put into to make sure this was also a good type. Checked all connectors. Measured voltage at the coils, which was also high enough. (I first thought it would be too low.)
And still the coils were weak ??

Double checked the bridge rectifier I had replaced. When I had soldered it in, it was almost touching the heatsink of the transistor that's below BR3. I had pushed BR3 a bit above so there was some more distance between the parts. Pushed BR3 again, and one leg came loose ?  Oops.. Seems it wasn't soldered well enough - one of the metal legs of the bridge rectifier didn't completely go through the board but ended about level with it. Either the connection was too thin for a lot of current to pass, or maybe there was some vibration that caused it.. anyway I resoldered the leg, added a bit more solder to all legs to be sure, and the problem was solved ?!

Always Coca-cola

This is one for the most original pinball repairs list.

Repaired a Dirty Harry in the rec room of a restaurant.
Didn't have many details, also was told that the ball sometimes got stuck.
Play-tested a bit and indeed sometimes it got stuck between two ramps.

Didn't see something obvious wrong with the ramps, they were still screwed in place, nothing loose.. so I was looking for something to fix the ball hanging.
Needed something to put in between them and add some spacing.. looked around, didn't find anything useful, except for one empty Coca Cola bottle.

Took the cap, cut it in half, and stuck it tight between the ramps.
You can see it in the picture - left of the house there's a metal post supporting the top ramp. The red cap is next to it, pushing the bottom ramp a bit down.

Now the pinball doesn't get stuck anymore. After taking this picture I put some grey tape over it to cover and keep it in place.