Hiya folks,

Just as the title suggests, the F104 fuse in my STTNG keeps blowing. Whenever I try to run the solenoid tests #'s 9-16 don't fire, which makes sense since that's the solenoid bank associated to the F104 fuse...

I looked under the hood and don't see anything obviously wrong with the coils, so where should I start to look for the culprit?

Thanks in advance for any suggestions!

Cheers,
Greg

Have you been told today? Have you? Well in case not... You're a superstar! Thanks Lloyd, I've been working on this game for a few days and I think the common sense hemisphere of my brain is a bit mushy.

Thanks a million!

So, with a fresh fuse, the coin door open, and the machine powered on everything is peachy. The moment I close the interlock switch (not in test mode, just as the game sits idle) the fuse blows.

That can't be normal. Any suggestions on where to start? Blown transistor or something?

Thanks again!

Cheers,
Greg

Thanks gents. I'll pop back down later on and give those suggestions a try. Thanks again for all of the help!

Cheers,
Greg

Well, it's getting narrowed down!

I pulled J127, and J107 the fuse doesn't blow. Yay!

Now I just need to find where the wiring/coil problem is and I'll be all set. Haha.

Thanks again for the point in the right direction!

Cheers,
Greg

Will do. Thanks again for the guidance, it's very much appreciated!

Well I've had some "progress".

I replaced a slingshot coil that looked a bit dodgey and hoped that would be the issue, so now...

Fresh fuse in F104, coin door open, J127 & J107 unplugged: Powered on and closed the interlock switch... No problem.

Power down and connect J127, coin door open: Powered on and closed the interlock switch... No problem.

Power down and connect J107, coin door open: Powered on and closed the interlock switch... POP goes F104.

I did a pretty good visual inspection of the Violet-Orange wire running between all of the solenoids and everything SEEMS to be good (although obviously it isn't).

Any suggestions on what to look for next?

Thanks again for all of the guidance folks!

Cheers,
Greg

Thanks for weighing in again Chris. Sadly, I wish I knew more about what that means. haha

I'm still basically an amateur with this fun stuff and have tried to essentially learn as I go. But I'm a little worried that I may be in over my head on this one.

Aside from continually doing visual inspections expecting to see something different that jumps out at me I'm at the limit of what my basic knowledge can tell me.

Maybe it's time to walk away from it for a day and try going at it again with a fresh brain.

Thanks again for the help!

Cheers,
Greg

Hey thanks Chris! That is a great link and illustration!

The only thing is that all of the coils (#9 through #16) on my STTNG don't have diodes between the lugs on the coils, and the coil sleeve part #'s correctly match the part numbers in the manual so I'm assuming they are correct.

Now that I type that I'm not sure if I specifically looked to make sure that they are all diode-less coils, so I should probably double check that before assuming.

* Coil wraps, not coil sleeves. My bad

So, is it reasonable to assume the the short lies somewhere within the chain of solenoids #9 through #16? (Since the F104 fuse is specifically for those solenoids?

Solenoids 9-16 are the left/right slingshots, the 3 pop bumpers, the trough, the top divertor, and the borg kickout.

I disconnected the Borg assembly and it still happened so should I be focusing on the remaining 7 solenoids? Or can the short reside elsewhere?

Heya Schwaggs, On the connector (with one lead securely tucked under the ground braid) pin 2 reads "1". As does every other pin on the connector.

That is with J107 and J127 disconnected and the machine off, as you instructed.

Heya Schwaggs, ok here's what I have...

Lead securely connected to ground braid (tested on the board screw which drops to ~0.03 when touched by the lead):

J107 pins on the BOARD read:
Pin 1: 9.93
Pin 2: 1
Pin 3: 9.93

J107 pins on the CONNECTOR read:
Pin 1: 1
Pin 2: 1
Pin 3: 1

J107 pins on the CONNECTOR after plugging J127 connector back into the board read:
Pin 1: 1
Pin 2: 0.00
Pin 3: 1

Does this make any sense?

Thanks again!

Cheers,
Greg

Exactly as instructed...

All pins on J127 connector read ~9.92

First off, thanks so much Schwaggs for taking the time to help me through this. It's immeasurably appreciated!

And I think we have progress!

Same setup as above...

All of the pins on the BOARD for J127 read "1"... EXCEPT for pin 4 which reads 0.00!

I'm guessing that's significant? *crosses fingers*

Oops! My bad...

It's actually pin 6 that's reading 0.00

I was counting left-to-right instead of right-to-left.

J127 pin 6 is the right jet bumper. Bad Q50 transistor maybe? Unfortunately I don't know how to test transistors with a DMM.

Thanks Chris, I'll go check that out now!

Well now I'm even more confused. lol

I tested all of the transistors associated to solonoids 9-16 and they all appear to be completely dead. 0.00 readings on all 3 posts of each transistor. But then I checked other transistors just to make sure that I was touching the leads correctly and I was getting different readings it seems from every single other transistor. Readings from .45, to 4.6, to 0.0, to whatever.

I would think that if there were that many bad transistors that the whole game would be dead, no? Everything else seems to function perfectly aside from solonoids 9-16.

I'm confuzzled...

Heya Chris,

It's not a good one. Was only about $30-40 on sale at Canadian Tire here. Is it maybe not accurate enough for this type of stuff?

Cheers,
Greg

DMM.png

I want to say yes... But I can't.

I'll pop back down to the shop and check the transistors with the correct DMM setting right after Better Call Saul. lol

Sorry to have wasted your time. I'll do better this time.

BCS is a lot better than I expected it to be. I'm pleasantly surprised!

Get back to you on my snafu in about a half an hour.

BAMMM!!!!

Q50 Transistor is bad. All others test within the limit that Chris outlined earlier. So excited to have it narrowed down to the offending component!

Now... I have to go to my local electronics store tomorrow to buy a boatload of 3A SB fuses since I've murdered all the ones I had on hand in the past two days, but as for that transistor... Would one of you fine gentlemen know what transistor to ask for when I go there? I'll buy several to keep a small stock of them, but I don't know offhand what the part number is for the transistor.

Thanks again guys! I couldn't have gotten this far without all of the generous help.

Cheers,
Greg

I've had such excellent help and feedback on this thread. I owe all of you guys a frosty malted beverage!

You're all awesome.

Cheers,
Greg

Wow, this is great! I'm actually looking forward to doing some board work tomorrow! (A year or so ago I wouldn't have thought to say that in a million years)

Thanks zaza. I'll be sure to check it before powering it up.

Cheers,
Greg

Will do Schwaggs!

Going to be heading to my local electronics shop within the next couple of hours and I'll stock up on the pre-driver as well. Thanks again!

A HUGE THANK YOU to all of you fine folks that participated in this thread. Everyone helped in a huge way!

I just played the first game on my now perfectly playing STTNG!!

I ended up having to replace the transistor, the pre-driver transistor, the resistor, and the right jet bumper coil (as it was cooked). So to everyone that offered assistance I give my sincere thanks! I know that it's "just an internet forum" but I am truly grateful. You offered your time and thought to help a complete stranger overcome a problem he never would have been able to on his own. Not only did you all help me figure out the problem areas, but actually taught me a great deal, and I just couldn't be happier. I owe you all. Cheers!

P.S. STTNG is such an awesome game!

Cheers to all of you,
Greg