(Topic ID: 239500)

Jurassic Park T-Rex Side-to-Side Motor Issues


By Mr_Tantrum

10 months ago



Topic Stats

  • 38 posts
  • 8 Pinsiders participating
  • Latest reply 9 months ago by winteriscoming
  • Topic is favorited by 4 Pinsiders

You

Linked Games

Topic Gallery

There have been 3 images uploaded to this topic. (View topic image gallery).

pasted_image (resized).png
IMG_2026.JPG
motor2 (resized).png

#1 10 months ago

I posted in JP club topic, but thought I would open to the community in general. Unfortunately, my electronics knowledge is limited so thought I would see if any experts could help me.

I have read everything I can find, but did not uncover my exact scenario with my T-rex side-to-side movement not working (previous owner informed me that he had disabled it, but hadn't had time to diagnose). Here is the situation this far:

- Blue power cable for motor was disconnected, so I reconnected for my testing (disconnected when done since I don’t want the motor running full time).
- Manual side movement is not possible (i.e. try to turn the T-rex by hand and it won't budge - no play in it at all).
- Removed motor from gearbox and manual movement is free (of course) and when looking into gearbox it appears that the gear that is visible is fully intact with all teeth.
- While motor is disconnected when I turn on pin the motor begins to run and never stops running.
- In T-Rex test mode, motor does reverse direction back and forth with press of left and right flipper buttons.
- If I hold the long gear that is attached to the motor while running, I can easily stop its rotation, but seems like the motor itself is still spinning (ie the gear is slipping).
- Voltage to motor is pretty constant 4.5V.

My first thought is why is the motor spinning at all times? Why is this not enough force to turn T-rex, and has this trashed the motor?

#2 10 months ago

The motor will spin at all times if you have the motor removed from the game, plugged up to power BUT not activating the dinosaur left/right switch to know when to stop. the motor.
Go into switch test and manually operate the dinosaur left/right switches and see if they work or not.

#3 10 months ago

All 3 switches test successfully (left, center, and right).

#4 10 months ago

You will need to disassemble and clean the gearbox of the old grease, and add new Teflon lube in. Very common

#5 10 months ago

If I loosen the two bolts holding the motor on or hold it by hand, it sort of works (moves left and right but at the end of the test sticks to far left (clockwise if looking at motor from bottom of playfield) but you can hear the motor still trying to turn. I need to find a video to see what the T-Rex test is supposed to look like on boot up.

Regarding redoing the gearbox, if that is indeed the issue can anyone direct me on how to uninstall it? I read somewhere that you have to drill out the rivets to get inside of the box (not a big deal) but I can't seem to figure out how to unmount it.

#6 10 months ago

How does one remove the gearbox from the machine so it can be worked on? I cannot figure it out, and I don't know how to remove the T-Rex assembly in general.

#7 10 months ago

I discovered there are 3 bolts holding the gearbox in place. Two of them are accessible from the top, but the third is completely blocked no matter what position you put the T-Rex in. Therefore, I still need guidance on how to remove the gearbox if anyone can please help.

#8 10 months ago

So, here is where I am:

1) From what I've discerned, the entire T-Rex mech must be removed in order to get to all of the screws to remove the gearbox. However, I cannot figure out how to do this, so I needs some help from the community.

2) In all of my working, I was able to loosen things up in the gearbox by manually rotating the T-Rex repeatedly. Now when I re-install the motor to the gearbox T-Rex will move side to side, but with issues.

3) Once power is applied to the pin, the side motor runs non-stop. T-Rex goes through its testing, but is off. In other words it rotates left and right, but tries to do it's bow while it is in one of the extreme outer positions instead of in the center like it should. When the test is complete it turns itself all the way to the left (counter clockwise) and then the motor never tops (you hear it humming).

4) I've visually checked the relay switch and shaker power board solder joints and they all look perfect.

At this point, I'm at a loss and appreciate an ideas.

#9 10 months ago
Quoted from Mr_Tantrum:

So, here is where I am:
1) From what I've discerned, the entire T-Rex mech must be removed in order to get to all of the screws to remove the gearbox. However, I cannot figure out how to do this, so I needs some help from the community.
2) In all of my working, I was able to loosen things up in the gearbox by manually rotating the T-Rex repeatedly. Now when I re-install the motor to the gearbox T-Rex will move side to side, but with issues.
3) Once power is applied to the pin, the side motor runs non-stop. T-Rex goes through its testing, but is off. In other words it rotates left and right, but tries to do it's bow while it is in one of the extreme outer positions instead of in the center like it should. When the test is complete it turns itself all the way to the left (counter clockwise) and then the motor never tops (you hear it humming).
4) I've visually checked the relay switch and shaker power board solder joints and they all look perfect.
At this point, I'm at a loss and appreciate an ideas.

I had an issue with left to right motor that originated from the shaker motor board. See more info here... specifically post 5234. I don't think it's your problem but may help you understand what is controlling that motor.

https://pinside.com/pinball/forum/topic/jurassic-park-club?tq=&tu=sataneatscheese

On your item number 3 above... it sounds to me like the power cords for the left right motor and up down motor may switched... They are inches away from each other and both use the same end plug.

#10 10 months ago
Quoted from sataneatscheese:

I had an issue with left to right motor that originated from the shaker motor board. See more info here... specifically post 5234. I don't think it's your problem but may help you understand what is controlling that motor.
https://pinside.com/pinball/forum/topic/jurassic-park-club?tq=&tu=sataneatscheese
On your item number 3 above... it sounds to me like the power cords for the left right motor and up down motor may switched... They are inches away from each other and both use the same end plug.

Thanks, I've read your thread multiple times and examined my board closely and it looks perfect. For #3, up and down and chomp work perfectly, so not sure that power could be reversed (also, when left/right trigger switches this does not cause any up/down movement). However, I will look at the power connectors regardless.

I'll try to post a video soon that shows the behavior, and maybe that will more clearly demonstrate my issue verses me trying to explain with words.

#11 9 months ago
Quoted from Mr_Tantrum:

I posted in JP club topic, but thought I would open to the community in general. Unfortunately, my electronics knowledge is limited so thought I would see if any experts could help me.
I have read everything I can find, but did not uncover my exact scenario with my T-rex side-to-side movement not working (previous owner informed me that he had disabled it, but hadn't had time to diagnose). Here is the situation this far:
- Blue power cable for motor was disconnected, so I reconnected for my testing (disconnected when done since I don’t want the motor running full time).
- Manual side movement is not possible (i.e. try to turn the T-rex by hand and it won't budge - no play in it at all).
- Removed motor from gearbox and manual movement is free (of course) and when looking into gearbox it appears that the gear that is visible is fully intact with all teeth.
- While motor is disconnected when I turn on pin the motor begins to run and never stops running.
- In T-Rex test mode, motor does reverse direction back and forth with press of left and right flipper buttons.
- If I hold the long gear that is attached to the motor while running, I can easily stop its rotation, but seems like the motor itself is still spinning (ie the gear is slipping).
- Voltage to motor is pretty constant 4.5V.
My first thought is why is the motor spinning at all times? Why is this not enough force to turn T-rex, and has this trashed the motor?

playing with mine right now too.. but to remove T-rex

You can do it without removing the top-side elements.. but I think it would be easier.
T-rex has an apron around him that sits above the large plastic that covers the raptor pit, etc. That apron is held by three screws that are blocked when T-rex is upright. Remove the screw in the back of the t-rex head to remove back half of t-rex plastic. Remove two screws at base of front of T-rex which hold the front plastic and rubber apron to remove front half of t-rex plastic. You should be able to get to the three screws holding the brackets holding the skirt plastic in place. Should be able to get t-rex out without removing the large plastic now (I didn't do this, so speculating - I had removed the large plastic as well)

To drop the whole t-rex.. just unplug the harnesses for the switches and motors. Remove the 4 wood screws holding the large bracket to the PF. Whole assembly will drop as a whole.

To get to gearbox... remove the e-clip and washer from the sliding pivot near the switches that track left/right/home stops. Be careful not to manage the switches accidentally.

After that, it's just the shaft from the gearbox holding the lower plate to the t-rex upper plate. Backoff the screw acting as the set screw on the shaft coming out of the gearbox.. and the two pieces will separate. The lower mounting bracket with gearbox.. and the upper assembly which has the up/down and t-rex himself.

Then you can get to the 4 screws that hold the gearbox in place.

#12 9 months ago

Thank you for the detailed directions! I appreciate it, as I’m sure others to come will also.

1 week later
#13 9 months ago

Just finished reflowing both shaker motor board and board that controls the motor switching rotation. Also verified fuses are good on shaker motor board.

I still have these symptoms:
- When power is applied to the pin, the left/right motor immediately turns on
- T-rex will go through a pseudo test in that it bows at the wrong position
- When test is complete T-rex is shoved all of the way to one side (i.e. it does not recenter)
- The left to right motor never turns off, once it reaches its side limit it just continues to run

I have verified in test mode that all T-rex related switches (left/center/right/up/down) operate appropriately and register their state correctly 100% of the time.

Does anyone have any idea of where my issue could be? For now, I just have to disconnect the power harness to the motor (2 blue wires).

FYI, I was previously on 5.13 code but now on Chad's 6.0 (same symptoms using both codes)

#14 9 months ago

It might be the motor. Youve checked everything else. I know it's expensive but there is one in the marketplace for slightly cheaper

#15 9 months ago

Looking at the manual, on page 31, the left/right motor is initially driven by a transistor Q27 (Solenoid Driver 12) on the CPU board. Is that transistor shorted? I wouldn't expect the problem to be upstream from there (the chip that drives the transistor), nor would I expect much else downstream if the motor is staying on continuously. When activated, this transistor completes the circuit for powering the motor, so if it's always on, that says me this transistor isn't doing what it's supposed to.

#16 9 months ago
Quoted from winteriscoming:

Looking at the manual, on page 31, the left/right motor is initially driven by a transistor Q27 (Solenoid Driver 12) on the CPU board. Is that transistor shorted? I wouldn't expect the problem to be upstream from there (the chip that drives the transistor), nor would I expect much else downstream if the motor is staying on continuously. When activated, this transistor completes the circuit for powering the motor, so if it's always on, that says me this transistor isn't doing what it's supposed to.

Thanks, I will definitely look into this.

#17 9 months ago
Quoted from edward472:

It might be the motor. Youve checked everything else. I know it's expensive but there is one in the marketplace for slightly cheaper

I really don't think it would be the motor. At some point something upstream is not cutting power to it when it should.

#18 9 months ago
Quoted from Mr_Tantrum:

Does anyone have any idea of where my issue could be? For now, I just have to disconnect the power harness to the motor (2 blue wires).

Just for giggles, can you verify that the cords coming out of your up and down motor are connected to the same color wires as they are in mine?

motor2 (resized).png
#19 9 months ago

For the record, I could be reading the diagram at the bottom of page 31 incorrectly, but it looks to me like the following:

1. The motor gets 9v supplied via the shaker motor board. This is the only thing coming from the shaker motor board, but is required. Obviously you have it since the motor is on. This 9v is supplied constantly to the bi-directional relay at 2 points - one for one direction when the relay is off and one for the other direction when the relay is on.
2. Q27, when active, connects one side of the motor to ground, completing the circuit to power it. I suspect this is where your issue is. If Q27 if off, then the motor should be off. It also connects to 2 points on the bi-directional relay - one for one direction and one for the other.
3. Q24 activates the bidirectional relay. When off, the motor would move one direction, and when on, the motor moves the other. This could be a secondary issue if it never moves the other direction, but could also point to a bad relay. Basically this relay is just swapping 9v and the path to ground between the 2 leads on the left/right motor - thus controlling the direction.

All this to say that the motor staying on constantly, as soon as powered up, says to me that Q27 is bad. Nothing should be activating it immediately upon powering up. That is THE component controlling the motor being on/off, nothing else, short of a bad hack or a bad chip upstream from q27 that keeps it locked on, should be allowing the motor to stay powered on.

#20 9 months ago

You are making lots of sense with your diagnosis. How do I test Q27 exactly? With pin off, I set meter to 2000k Ohmns, I put negative lead on Q27 center pin or hole at top of transistor (tried both), and then put the positive lead on either outer pin, and I get about the same reading on both pins. Tried this with an adjacent transistor and got similar readings.

Must I physically remove it from the board in order to test properly?

FYI, motor does switch directions during testing, so T-rex does go clockwise and counter-clockwise (i.e. bidirectional relay appears to be working).

#21 9 months ago
Quoted from sataneatscheese:

Just for giggles, can you verify that the cords coming out of your up and down motor are connected to the same color wires as they are in mine? [quoted image]

Yes, my connections are just like yours.

#22 9 months ago
Quoted from Mr_Tantrum:

You are making lots of sense with your diagnosis. How do I test Q27 exactly? With pin off, I set meter to 2000k Ohmns, I put negative lead on Q27 center pin or hole at top of transistor (tried both), and then put the positive lead on either outer pin, and I get about the same reading on both pins. Tried this with an adjacent transistor and got similar readings.
Must I physically remove it from the board in order to test properly?
FYI, motor does switch directions during testing, so T-rex does go clockwise and counter-clockwise (i.e. bidirectional relay appears to be working).

Probably testing when removed is best. If you don't have another TIP122 (I believe that's what it is) to just go ahead and swap in, you could also swap Q27 and Q24 to see if the motor starts behaving and the left/right relay stays locked on. If the behavior remains the same and the transistor is good, I'd start looking at the chip that drives the transistor, but that gets more complicated. You could at least tell if it's locking Q27 on with your DMM.

#23 9 months ago

I have a Rottendog board, and the chip number is FQP13N10L. I just retested with MM in diode mode and Q27 gives the same readings as multiple other transistors on SD12.

Your thinking is that the transistor is stuck "on" (i.e. the circuit is complete at all times)? If so, looking like my only option for now is to remove the board and put a new transistor in (I will have to order some).

IMG_2026.JPG
#24 9 months ago
Quoted from Mr_Tantrum:

Your thinking is that the transistor is stuck "on" (i.e. the circuit is complete at all times)?

Yes - this is the only reason the motor would be constantly powered, as far as I can figure. It would have nothing to do with the left/right/center switches if it's always on the game wouldn't even be checking these initially until it got into t-rex diagnostics which takes a couple seconds to get to when booting.

You can check for voltage at the base pin of the transistor to see if it's getting locked on by the chip that controls it. I'm not sure what the logic level (i.e. what the voltage level is to turn it ON) is on this board, but compare it to the base on a transistor for a solenoid that you know is off (I assume 0v for off).

Obviously testing while the game and boards are powered comes with risks of shorting something out or worse, so be careful.

#25 9 months ago
Quoted from winteriscoming:

Yes - this is the only reason the motor would be constantly powered, as far as I can figure. It would have nothing to do with the left/right/center switches if it's always on the game wouldn't even be checking these initially until it got into t-rex diagnostics which takes a couple seconds to get to when booting.
You can check for voltage at the base pin of the transistor to see if it's getting locked on by the chip that controls it. I'm not sure what the logic level (i.e. what the voltage level is to turn it ON) is on this board, but compare it to the base on a transistor for a solenoid that you know is off (I assume 0v for off).
Obviously testing while the game and boards are powered comes with risks of shorting something out or worse, so be careful.

Yeah, I'm not going to test while game is on . . . too easy to arc something. I've made the mistake before a couple of years ago on my Getaway and told myself I would be disciplined enough to never do it again, since it always ends up costing more headache, time, and scratch.

#26 9 months ago

I can try to figure it out, but can you tell which chip controls it? Might be easier to order both parts at the same time and save on some shipping.

I'm decent at most electronics, but very limited experience. Very grateful when people like you help out and point me in the right direction. Thank you.

#27 9 months ago

Hey I'm not an expert on testing these but those are FET transistors not TIPs, its a rottendog.
https://pinside.com/pinball/forum/topic/how-to-test-a-fet-transistor

#28 9 months ago
Quoted from supermoot:

Hey I'm not an expert on testing these but those are FET transistors not TIPs, its a rottendog.
https://pinside.com/pinball/forum/topic/how-to-test-a-fet-transistor

Thanks, I'll check it out.

#29 9 months ago
Quoted from Mr_Tantrum:

I can try to figure it out, but can you tell which chip controls it? Might be easier to order both parts at the same time and save on some shipping.

I'm decent at most electronics, but very limited experience. Very grateful when people like you help out and point me in the right direction. Thank you.

I don't know how much the Rottendog board differs from stock. I'm only reading the stock manual here, but it appears that the next thing up-stream is a resistor array RA25, which I think is acting as a pulldown resistor for Q23-Q30. However, it looks like Q23-Q30 are each driven by another transistor - Q15-Q22. Q27 appears to be paired with Q19, so check that one as well. Q19 has, I believe, a pull-up resistor in resistor array RA7. These are driven by a 7408 quad gate. Specifically Q19 is driven by the gate chip listed as 2J at pin 6. This is driven by the chip at 5f - which is a 6821 - a Peripheral Interface Adapter (PIA). I can't glean any information about how it works upstream from there, but I actually would rule out the transistors before blaming the PIA. I guess a quad gate could be bad - and there are likely testing procedures for that.

So, if the Rottendog is the same, I'd be checking/replacing Q27 AND Q19 and rule those out before suspecting other components.

#30 9 months ago
Quoted from winteriscoming:

I don't know how much the Rottendog board differs from stock. I'm only reading the stock manual here, but it appears that the next thing up-stream is a resistor array RA25, which I think is acting as a pulldown resistor for Q23-Q30. However, it looks like Q23-Q30 are each driven by another transistor - Q15-Q22. Q27 appears to be paired with Q19, so check that one as well. Q19 has, I believe, a pull-up resistor in resistor array RA7. These are driven by a 7408 quad gate. Specifically Q19 is driven by the gate chip listed as 2J at pin 6. This is driven by the chip at 5f - which is a 6821 - a Peripheral Interface Adapter (PIA). I can't glean any information about how it works upstream from there, but I actually would rule out the transistors before blaming the PIA. I guess a quad gate could be bad - and there are likely testing procedures for that.
So, if the Rottendog is the same, I'd be checking/replacing Q27 AND Q19 and rule those out before suspecting other components.

Very similar on the RD schematic: https://docs.wixstatic.com/ugd/846ba2_f2ba4a3d9e1c48b893a7a20d679c4ac2.pdf

#31 9 months ago

After following this:

I think that my Q24 is bad. I tested several transistors, but Q24 is the only one that gives abnormal readings (like the second transistor in the video).

I don't know how to read electronics schematics, but it appears that Q24 has a role to play in the power being on or off to the motor. Your thoughts?

pasted_image (resized).png
#32 9 months ago

As far as I can tell:

Q24 is simply turning the bi-directional relay on or off. It doesn't control the motor being on or off, just left or right.

Q27 is what controls whether or not the motor is on.

The motor in that diagram is a circle with a tilde in it. It has a blue lead and a blue/white lead. These both connect to separate common points on the relay. The relay takes in 9v and a connection to Q27, which allows a path to ground when active. 9v connects to 2 points, and Q27 connects to 2 points. When off, the relay provides 9v to the Blue lead and the Blue/white lead goes to Q27. When the relay is on, the 2 switches in it flip so that the Blue lead goes to Q27 and the Blue/white lead goes to 9v.

You should at least disconnect the connectors that go to the coils/relays/motors for in-board testing. You could be getting different results on your readings from the downstream components.

#33 9 months ago
Quoted from winteriscoming:

As far as I can tell:
Q24 is simply turning the bi-directional relay on or off. It doesn't control the motor being on or off, just left or right.
Q27 is what controls whether or not the motor is on.
The motor in that diagram is a circle with a tilde in it. It has a blue lead and a blue/white lead. These both connect to separate common points on the relay. The relay takes in 9v and a connection to Q27, which allows a path to ground when active. 9v connects to 2 points, and Q27 connects to 2 points. When off, the relay provides 9v to the Blue lead and the Blue/white lead goes to Q27. When the relay is on, the 2 switches in it flip so that the Blue lead goes to Q27 and the Blue/white lead goes to 9v.
You should at least disconnect the connectors that go to the coils/relays/motors for in-board testing. You could be getting different results on your readings from the downstream components.

Not arguing here, just trying to make sense of things to myself. I think I understand your explanation of Q27. Basically, it's off/on state dictates the position of the gates (open or closed), which in turn dictate the polarity to the motor causing it to spin either clockwise (e.g. gates open) or counter-clockwise (e.g. gates closed). If I'm understanding that correctly, then given my symptoms Q27 would appear to be functioning normally as my motor successfully changes rotation. So what would be the impact if Q24 was constantly feeding power to the relay? Is the relay's state of having power to it being on or off not what impacts the motor being on or off?

#34 9 months ago
Quoted from Mr_Tantrum:

Not arguing here, just trying to make sense of things to myself. I think I understand your explanation of Q27. Basically, it's off/on state dictates the position of the gates (open or closed), which in turn dictate the polarity to the motor causing it to spin either clockwise (e.g. gates open) or counter-clockwise (e.g. gates closed). If I'm understanding that correctly, then given my symptoms Q27 would appear to be functioning normally as my motor successfully changes rotation. So what would be the impact if Q24 was constantly feeding power to the relay? Is the relay's state of having power to it being on or off not what impacts the motor being on or off?

I think your assumptions are reversed regarding Q27 and Q24. If Q24 is locked on, it just keeps the relay on and the motor will only go one direction (when the motor gets power). The motor's power is essentially switched on and off by Q27. Q27 being locked on means the motor is on, regardless of the state of the relay. The relay (controlled by Q24) is only controlling polarity (and therefore direction). Q24 could be removed and the relay in its off state would still allow the motor to move one direction if the motor is powered.

For the record: I believe the diagram is misleading, by labeling Q27's connection to the relay as (LEFT/RIGHT) BRN/YEL. That isn't controlling left/right - just the path to ground via Q27.

The motor is always getting 9v on one lead and goes to Q27 with the other lead. All solenoid driver transistors give the solenoid/motor/relay a path to ground when activated. Imagine instead of Q27, you had a wire that you could manually ground to turn on the motor. You would only touch it to ground when you want the motor on. If you touched it to ground and kept it there indefinitely, the motor would spin indefinitely.

#35 9 months ago

The RD board is different. It doesn't have pairs of transistors and as many gates driving the solenoids.

Q27 appears to be driven directly by U1 74HCT244, with nothing major between them. RA7 is still used as a pull-down resistor.

#36 9 months ago

Q24 was the culprit. I had remembered that I had to repair the Rottendog board in my Getaway so I checked my supplies, and sure enough I had two of the correct transistors (FQP13F10L). Since the meter pointed to Q24 being bad, I thought I would try it first before also doing Q27. Made the repair, reinstalled the board, plugged in my T-Rex side-to-side motor, turned pin on, went into service modes and enabled side-to-side, exited, and gave it a whirl. T-Rex test worked perfectly. Turned pin off and back on to play a normal game, and T-Rex is fully functional now.

Thank you, WIC, for all of your help, research, and pointing me in the right direction.

#37 9 months ago
Quoted from Mr_Tantrum:

Q24 was the culprit. I had remembered that I had to repair the Rottendog board in my Getaway so I checked my supplies, and sure enough I had two of the correct transistors (FQP13F10L). Since the meter pointed to Q24 being bad, I thought I would try it first before also doing Q27. Made the repair, reinstalled the board, plugged in my T-Rex side-to-side motor, turned pin on, went into service modes and enabled side-to-side, exited, and gave it a whirl. T-Rex test worked perfectly. Turned pin off and back on to play a normal game, and T-Rex is fully functional now.
Thank you, WIC, for all of your help, research, and pointing me in the right direction.

Congratulations! Nothing like getting you pin working again after seemingly being at the end of your rope.

#38 9 months ago

Glad you got it working!

I still don't see how that transistor could have locked the motor on, but I suppose there's a potential scenario where the game wanted to get the t-rex to a specific point, so kept powering it and never achieved it.

However, you indicated that the t-rex would move both directions, so I would think the transistor that controls the relay wasn't the issue... so maybe Q24 doesn't control the relay?

It's entirely possible that I'm misreading the diagram or that the diagram has the transistors mislabeled.

At any rate, it probably doesn't merit further exploration if you're up and running now.

Promoted items from the Pinside Marketplace
$ 49.95
Lighting - Led
Pin Stadium Pinball LEDs
$ 7,599.00
Pinball Machine
Classic Game Rooms
$ 29.95
Playfield - Toys/Add-ons
ULEKstore

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside