Tim's STTNG thread

[slacker]

OMG not FS or FT a real "I got a broken pin and now we are going to fix it post! Way to go Tim I love following the Tim Sanders bring it back from the dead threads! Good luck buddy very cool Pin and a long way from a rescue 911. Cheers! J..

 

[tim.sanderson]

OMG not FS or FT a real "I got a broken pin and now we are going to fix it post! ... a long way from a rescue 911. Cheers! J..

Haha yup, it's been a while. I've had quite a few pins roll through since my last thread, I felt like a slacker! (see what I did there?)
Yeah, R911 was my last/only pin that was a DMD. I felt it was time to treat myself.

P.S., say hi to Jen for me!

 

[tim.sanderson]

...a long way from a rescue 911.

What's crazy is, I believe R911 and STTNG were released the same year. What a contrast between the two!

 

[Chris Bardon]

What happens if you just completely disconnect the aux driver board? If the problem is between the main driver board and this one, then maybe things will work differently?

Honestly, I think part of the reason we don't see more threads like this is that the "old, basket case" games aren't near as plentiful as they used to be. When everything has already been fixed and put into private collections where it's not getting beaten on, there are less beater games to find. Sure, there are the restores happening, but the number of games that have been sitting in operator warehouses for 10 years, or brought over on a container seems to have dried right up. Either that, or the people who are getting them aren't saying much anymore.

 

[tim.sanderson]

A bit of an update.
My PS's 5v gave me a solid 5v with no load, but when I took a reading from the board it was 4.3v. So I turned up the pot until I hit 5v.
The board now reacted mostly as it should. Now I realize there isn't 5v getting to the CPU at all. So now I've got to follow things back until I get a 5v reading. I'm going to print off the schematics and see where that gets me.

 

[tim.sanderson]

My PS's 5v gave me a solid 5v with no load

This was still on the bench, BTW... when I put it back in the game is when I have no 5V

 

[Menace]

5V section on the driver is clearly bad, it's a relatively simple circuit and shouldn't be difficult to sort with the schematics.

Also don't get too far ahead of yourself regarding the cannons. They will also do that if the game boots up but the regulated 12V is missing for the opto's.

D

 

[tim.sanderson]

So, I've been slacking on posting updates...

**SPOILER ALERT**
The game totally plays now! On top of having 5V issues on the power driver board, it turns out the MPU was grumpy, too. I was getting fuse errors, even though the fuses were fine. Also, leaking batteries wreaked a little more havoc than I was expecting. For example, even when I put new batteries in it, it wouldn't hold the settings. So I bought a new Rottendog MPU. It seemed worth the $200+ for a little piece of mind.

It would seem the 5V power issues were coming from bad traces between bridge rectifiers and capacitors. So I did many of the jumpers that the PinWiki had listed:

As you see, it looks like a previous tech soldered in the bridge rectifiers with a butane torch. Menace told me there's a spray you can buy to remove all that excess flux residue. I put the boards back in, and the game fired right up!

I'd like to clean that mess up, but for now I'm just happy it plays so well.

Thanks to Menace and Grauwulf for the tech support!

There's still some board work to do, (like re-pinning the melted GI connectors on the Power Driver board) and some repairs to do, so I'll try to post a little more frequently.

 

[tim.sanderson]

Today I'm investigating why my upper flipper almost never makes the shot all the way around the left orbit... even when the shot is perfect. The Picard Maneuver just can't be made. I took the glass of and poked around the flippers. I've noticed the left flipper, when raised, doesn't react well to an opposing force. When the ball hits it with a modest amount of force, it flips it off:

It's pretty easy to push it down by hand, too. Something to do with the End Of Stroke (EOS) switch is my initial suspect...

 

[Menace]

I think you're on the right track Tim...

D

 

[tim.sanderson]

So, last night, STTNG developed the ol' flutter/double flip problem:

The flipper flips twice, and was unable to cradle the ball. The upper flipper was unaffected, and could hold, no problem. This ruled out a problem with an opto board. To be safe I swapped the left and right flipper optos. Alas, the problem stayed with the lower-right flipper.

I removed the coil from the game to give it a closer inspection. I found one of of the windings broke off it's leg of the coil:


I unwound the wire one rotation and stripped the coating off. I soldered it back onto it's lug, and everything worked swimmingly.


Huzza!

 

[Chris Bardon]

Interesting-don't think I've ever seen that fix before. Good to know!

 

[Menace]

Good catch Timbo. Can't tell you how many service call's I've done where just pulling back one winding and re-attaching to the lug is all that is needed... Makes me wonder how many people have tossed perfectly good coils in the trash because of this?

D

 

[tim.sanderson]

The next step was to replace the melted GI connector on the Power Driver Board. This connector sends the power to the back box GI. As you can see, J120 got hot enough to melt the connector into two pieces:


This is the back side of the board:


With the help of my handy solder pump, I removed the male half of the connector from the board.


I soldered in the male side of the new connector:


I don't have a crimper yet (not sure why, really), but seeing as there are only 4 pins used in this connector, I did them by hand. Crimped with needle nose pliers, then soldered to be safe.


I clipped them into the female side of the connector, and plugged it back into the board.


I fired it up, and only the LEDs on the yellow string have lit up. I'll have to look into why that is. But until then, at least the backglass isn't totally dark.
**EDIT** Prior to reinstalling the board I tested the continuity from the pins to well past the burnt parts, so I know it's not a break caused by the burn **EDIT**

 

[tim.sanderson]

Oh yeah, I forgot to say thanks to Spiro Agnew for sending me the parts!

 

[tim.sanderson]

Yesterday, my lower right flipper developed a serious weakness problem. A perfectly shot left orbit couldn't even make it half way around. Here's how it looked:

The first thing I tested was the end of stroke (EOS) switches. They were all working fine.
Second thing I tried was swapping the coils. The weak flipper stayed on the lower right side.
The third thing I tried was swapping the flipper opto boards:

Wouldn't you know it, both sides were back to full strength. I have a feeling that re-seating the connector was probably what worked. Now both sides are full of their usual pep and vitality:

 

[Menace]

Tim, if you notice the flipper getting weak again try cleaning the opto's with a q-tip and rubbing alcohol. If it's still weak it could also be a failing opto. I see this more than you know during my travels.

D