Board LED lighting with metal ball means the detector is working OK. But there might be a bad connection in the cable. Check that all pins on the board J1 connector are well soldered, and the cable side connector is clean. If the cable feels loose, replace connector pins.

OK. Not a connector problem then.

Is your menu setting A2.26 "No powerball" set to "NO"? And is the slot machine eddy sensor also working correctly?

The proximity sensor (switch #57) is in the subway between the camera and the slot machine. Putting a ball into the slot machine, will not test the proximity sensor as the ball doesn't roll down the subway over the sensor. To correctly test the sensor, place the machine into switch test mode and put a ball into the camera (actually it might be easier to drop it into the exit of the gumball) - as metal ball rolls down the subway it should trigger switch #57 before arriving at the slot machine triggering switch #58. Note only the last switch triggered is shown on the display, so you have to watch the display as the ball rolls down the subway.

What version of code are you running? Have you tried doing a factory reset to start from a known configuration?

That's quite an old revision - you'll find information about the new versions here http://www.planetarypinball.com/mm5/Williams/tech/roms/twilight.html

If your machine is for home use (ie free play) then I recommend that you buy the TZ 9.4H game ROM.

The latest sound ROM is L-2, your game may already have this but if not then you could get the sound ROMs at the same time.

Is the machine showing a credit dot or when you go into the services menu does it flash any errors up on the DMD?

Next thing to check, go into switch test mode and watching the matrix on the left side of the DMD go through activating each switch - check on the matrix that only a single switch is being turned on. If there are any cases where multiple matrix lights are going on when you are pressing a single switch please take note of what matrix (row and column) they are.

Also can you confirm:
1. Every ball, of every game, when the ball (regardless of whether a metal or the ceramic ball) is ejected from the trough the machine says it is a Powerball - right?
2. If the ball in play is a metal one and the game is in Powerball mode, and you put the ball into the camera subway hole, does the machine continues to stay in Powerball mode or does it realise it's a metal ball and it stops the Powerball mode?

Maybe you could also take a video of these 2 steps and post for us to look at.

If you install a new ROM version, you will lose the high scores anyway, so maybe you could try resetting to factory settings with the L-4.

First great pics and videos - it really helps!

So while switch #26 seems to work in test mode, for some reason the machine is not seeing it during a game ...

But we have determined that switch #57 works both in test mode and game mode (that's a good start )

I saw in one of your videos there was no credit dot, so the game is not aware of any errors.

Did you do the below test?

Have you noticed any other "strange" behaviour during gameplay that is not normal?

Can you go into the setting and change "No Powerball" to "Yes" - does the machine still think every ball is a powerball in gameplay?? Then go back into setting and change it back to "No" - how does it recognise the balls now in gameplay? If you could video doing these changes and the game play it'd be great

Thanks for letting me know - no need to do the video of what happens when No Powerball is set to Yes.

If you could do the switch test looking for any multiple matrix lights when activating activating a switch please.

Also what brand is your Switch 26 proximity sensor board (I can't quite read it)? Is this new or was it previously working in your machine?

I notice that the proximity board has LEDs, could you take a video of the board and the bottom of the trough (similar to the picture below) when you play a game - load the trough with a metal ball, then the ceramic ball and then a metal ball. I would expect the LED to be on (metal ball detected) when you start you game, it should kick the first metal ball into the shooter lane (not start powerball) and the ceramic ball would roll up to the sensor but not trigger switch 26 (the LED would remain off). Plunge the first ball and catch it, wait for the ball save to go off (if it is on) and then let the ball drain. With switch 26 LED off, it'll now kick out the ceramic ball into the shooter lane (and start Powerball mode) while the next metal ball will roll up to the sensor and the switch 26 LED should turn on. Let the ceramic ball drain and play the last ball as well. Do the video from the start to the end of the game, this way I'll be able to tell what is happening by the game sounds recorded. Thanks we'll get this sorted out!!

TZ Switch 26 (resized).JPG

Just double check that your trough switches are working correctly - empty the balls from the trough, go into switch test mode (switches 15, 16, 17 & 25 in the matrix should be off), drop one ball in (the matrix should now show 15 on but 16, 17 & 25 off), drop the second ball in (the matrix should now show 15 & 16 on but 17 & 25 off), drop the third ball in (the matrix should now show 15, 16 & 17 on but 25 off) - right?

Then run the test scenario from my last post, videoing the proximity board and bottom of the trough while playing a game. You may need to put some light into the cabinet to get the video

I noticed the video shows 4 balls being launched - do you have your machine set to 5 ball game?

At the very start of the video, I assume that the first ball in the trough is a metal ball (I can't actually see the bottom of the trough in the video) and the LED should be on HOWEVER IT ISN'T - hence why the game is treating the ball as a powerball. When it is kicked in the shooter lane and played, the ceramic ball is at the sensor and the LED is correctly off. When the ceramic ball is kicked in the shooter lane and played, the next metal ball is at the sensor and the LED is correctly turns on HOWEVER at the 24 second mark the ceramic ball drains and while the game is showing the score bonus the LED TURNS OFF, so when goes to start the next ball it checks switch 26 which is now off and so the game believes it's a powerball.

So the issue seems to be the proximity sensor - it doesn't seem to be working at the particular time the game is checking it's status. I don't know the specific brand of board you are using and not sure if it has a fault or if it's just the position of the sensor and ball as the machine loads the ball from the outhole into the trough causing the issue (however this would be more inconsistent). Do you have any local friends with a TZ that you could swap the promity board with to test?

Do you still have your old eddy board that you replaced 6 months ago and was it working?

Bam. This probably is your problem. Noise in the system if this component isn’t performing to spec.

How is this a problem? Just hit the right orbit over and over again!

The damage the induction coil has suffered is common. When you position and attach the board to under the playfield, firstly check that a ball sitting in the trough isn't touching the coil but then move the coil slightly back a little as when a ball is loaded into the trough from the outhole it'll have momentum and quite often hit the coil before coming to rest and in doing so cause the damage. Once the board is fixed into place, you can then adjust it's sensitivity to ensure that it detects the metal balls.

Will be curious if this solves the problem. I had some flaky issues with my TZ and I ended up having to fix the 12v power on the board. The capacitor that was part of the 12v was bad.

Congratulations, glad to hear you got it sorted out. I find it strange that the proximity sensor LED would come on with a metal ball in the trough but only while the current ball was in play. Given the plastic covering on the induction coil was broken off, maybe a metal ball in the trough would touch the coil and short it however why would the sensor LED come on at other times. Anyway good to see it working again - all the best

I had lots of problems with the (original!) Trough Prox. board on my TZ misreading powerblls and metal balls, and incidentally, the coil on minet is in an even worse state than the one in your pictures!

But after reading a LOT of postings online, all the smart money was on removing "that lousy two-pin connector" and soldering the cables direct to the pins on the TP board. Without much real faith, I did as everyone suggested and … hey presto! All problems gone and my TP board works perfectly now.

It looks like your replacement TP board doesn't have the connectors on it (?), so I guess that's not going to be an issue for you. But I thought it was worth mentioning here, just in case any other TZ owners are going crazy with this.

Really pleased you got your problem fixed!

That replacement board still has the 2 pin connector (highlighted with the yellow circle) however being new the contact with the header is possibly better. Definitely can be an issue if using the original board set.

TZ prox PCB (resized).jpg