Hi All,
I have an issue with my Jurassic Park pin, where the left flipper loses power after a while of playing.

I have rebuilt the flipper, but it still happens.

When I switch the machine on and start playing it always feels slightly weaker than the right flipper, enough so that I struggle to shoot the ball up the right ramp. After a few minutes of playing it starts losing more and more power until eventually it hardly flips at all. I can move the flipper by hand and it feels free, so I'm not sure what it could be. Switch the machine off and leave it (usually days between plays, so not tried it straight away) and it works again although weaker than the right.

Any ideas?

Bill2626,

Thanks for the link, I've used pinrepair before when I had a short-circuit in the pin which blew a lot of components on the system board. I bought the pin from Poland and it's been messed with quite a bit inside (loose wires - don't know where from as everything appears to work ok).

Pinrepair was fantastic with the pictures and explanation, so I managed to fix it then. The flipper section has changed since I originally looked at it about a year ago, so apologies for not looking back at it.

I'll spend some time looking at all the points on there and see if it helps - some of the items sound very interesting....

Thanks

Update:
I noticed that the Flipper Board had a fuse blown and was extremely messy (last owner had soldered Fuses onto broken clips!), so I de-soldered the clips and re-soldered new ones and replaced the fuses. All testing ok.

Anyway, I've read the Flipper section on pinrepair and other than a re-build everything tests fine.

The issue I have seen is that the left had Flipper plunger is worn, as if the coil is too tight and the behaviour I am experiencing is a slightly weaker flipper on the left to start off (cold machine), which within minutes deteriorates. I switched the machine off and felt the coils and the left was hotter than the right, so either the coil was faulty when I replaced it, or something is causing the coil to overheat.

I did a re-build on the flipper not long ago, so I am about to order a new plunger and coil for that side, but before I do - anybody got any idea if it could be anything else that is causing the coil to overheat, so I don't go to the expense of re-building for it to happen again?

Thanks phrmtek,

I finally got time to take a look again. I replaced the EOS switches on both flippers a while ago as they were both pretty mangled. I have checked them both and they are working as expected. I can see the voltage peak and then drop off - the same voltages are present on both the left and right, so the behavior of them seem to be identical.

I've just had the game running for a few minutes and constantly hit the left flipper and as usual after 5 minutes it gets weaker and weaker until finally it hardly moves a couple of millimeters. When I lifted the playfield to take a look I touched the right coil - hardly warm, left one!! Jees nearly stuck my finger to it, it was that hot. Also the other day I noticed that when I move the flipper myself slowly I can here the plunger grinding in the coil (as it must already have warped the nylon sleeve with the massive heat).

Everything I check on the left shows as the same as on the right (good flipper), voltage, resistance. All fuses are in tact.

I replaced the left coil myself at some point, so either I got a duff coil, messed it up myself or there is something else on the flipper board that is at fault?

Is it worth me getting a new coil and trying again or do you think there may be something else at fault upstream?

Update:
I finally got time to take a look at my pin. I swapped the coils over and the weak flipper was then the right bottom one, so I suspected it was the coil.

I ordered some new bits and today had a go at doing a flipper rebuild and putting a new coil on the right lower.

Well, I replaced everything (bearing in mind I played on the pin the other day for about an hour with no issue) and when I switched the game on the right flipper flicked up and I saw the fuse blow! I checked the diode on this new coil (detached on leg and used the DMM on diode test) and it was fine.

I just tried to get a reading from the flipper with the DMM by putting in another 3A slow blow fuse and it did the same (blew the fuse).

It all seemed to be working ok before (apart from the weak flipper) - does anyone think it may have been the flipper board all along (transistor issue?)

I went onto pinrepair to check what it was and it's closed to the public - can't seem to see a way to subscribe - any help please?

Ok - I have found the issue, I shorted out the TIP36c and TIP102C (mine was a TIP32C, but I replaced with TIP102C) on the Flipper board (proper noob trick I know!). I didn't get a replacement MPS-A42 (again the latest are named 2N4401 now) as it sounded out ok using a DMM on Diode test.
I put the board back in the pin and switched it on and both bottom flippers flipped once and returned to rest (as is they were stuck on?), didn't blow a fuse (so I think I definitely fixed that issue as it kept blowing the fuses as they were stuck on).
So, the issue is now that non of the flippers will flip, I can hear them energise and see the plungers slightly moving, but they don't seem to have enough power to move (I've checked mechanically and they will slide through easily, so they aren't stuck).
I've tested with the DMM and I think there isn't enough current getting to them?
Resistance of all coils is good ~ 4.1 ohms
Voltage goes ~20v on flip to ~4v on hold
however when I check the current only .6 Amps is driving the circuit - is that correct? I thought it would be higher than that.
What do you think - could it be the 2N4401's that need replacing too as like I say the machine flipped once when I switched it on making me think that a transistor may have been shorted on?
Thanks.

Hi Firebaall - I found a way to get the info from there thanks and have it stored.

Pinwiki is a great site too.

Anybody help me with the power issue to the coils?

Hi guys,

Just to tie the loose ends on this thread - I fixed this with a new coil, but also did flipper rebuilds on both sides whilst I was at it.

The thing is though - it was a new coil I'd fitted previously, so it must have come to me with defect windings.

All good here now and the pin is way stronger now, can get all the hard to reach ramps, orbits now!

Cheers for you help and suggestions.