I'm having troubles figuring out a time expander problem. The middle target on the second level will not register. I've replaced both sender and receiver optos. The weird thing is, when I touch the 2 pins of the receiver opto (on the solder side) the target registers correctly. It doesn't take any pressure at all to make it work. Just bridging the receiver pins with my skin makes it work perfectly. Does this point to a resistance problem? Maybe the problem stems from the 10 opto board under the playfield?

I've put new solder on every wire, opto sender, receiver and checked my molex connectors. If I hold my finger on the receiver opto I can move the whole assembly around any which way and it works flawlessly. The second I stop touching the receiver opto prongs it quits working.

Essentially using my fingertip as a jumper, yes. But as a test, I did jumper the receiver prongs with a wire and the target still would not work. I removed the jumper wire, touched it with my fingertip and it works flawlessly. Which is why I'm thinking it's a resistance issue.

Do the receiver optos have a polarity? I noticed the sender optos have a notch drawn on the board to show which way to insert them. The receiver optos did not have that notch and are just circles.

I swapped the 10 opto board from under the playfield with the 10 opto board out of my BSD. The time expander targets work perfectly now. So I guess I’ve gotta shell out $100 for a new one. Bummer, but at least I can stop taking this time expander apart all the time for testing.

I’ve ALMOST got my game 100% working. The last problem I can see is a couple flashers not working. The Doctor 7 (middle backglass doctor) and the time expander flasher are not working. They are on the same circuit and should flash at the same time. I have continuity from the board to the bulbs and have checked for cold solder joints on the back of the board.

While I had the driver board off, I noticed that transistor Q42 (the transistor that controls said flashers) is a TIP122 but the manual calls for a TIP102. It’s obviously been replaced at some point. Would this cause the flashers to not operate?

Both flash lamps that aren’t working are socketed, not on boards. Both have continuity to the sockets from the driver board.

How would I go about shorting the transistor to test? Do you do this with the machine powered on and everything plugged in?

Is the predriver transistor 2N5401?

Anyone have insight on this? I have a new TIP102 transistor coming this weekend and if the predriver transistor is a 2N5401, then I already have a couple of those from a previous display repair.

Well, I'm out of ideas at this point as to what could be wrong with my middle target on the time expander. A new 10 onto board didn't fix the problem like I thought it would. I've found that if I unplug the optos under the playfield (the 12 molex connector) then plug it back in, the switch works fine for a few seconds, then starts freaking out, then stops working completely. Take a look at these two YouTube videos I took to see what I'm dealing with. Has anyone ever saw this type of behavior before? I've checked all continuity from the opto board to the CPU and all connections are solid. I've also replaced the sender and receiver optos with new ones.

Here is video of what happens when I plug the optos in and don't touch anything:

Here is a video showing the middle time expander switch working for a second and then stopping:

So frustrating.....

Thanks for the info. I'll try adjusting it tonight and report back.

That's the LED version. I have both LCD and LED in my lineup and prefer the LED version. It fits into certain games easier because of its size and it costs a bit less than LCD.

After many opto adjustments, I still couldn’t get the middle time expander target to register. As a final shot in the dark, I decided to replace the optos thinking maybe I had received a faulty one. Started with the receiver opto. Plugged the target bank in to test and boom....100% working.

Flipper alignment question. Should the tips be pointed (centered) at the holes in the playfield? Right now, mine are lined up where the guide rails are flush with the flippers. If I were to point the flippers at the holes, they look like they would be pretty droopy compared to the guide rails.

3A54F394-82A5-408C-A8A8-7F913AC92377.jpeg

6E9CF67D-85C4-4566-B48E-26183175C6FB.jpeg

I decided to bite the bullet and remove the old, dirty and bubbly mylar from my Doctor Who. It took a lot of time and effort since the mylar was covering the ENTIRE playfield but I'm so glad I did it. The playfield underneath is immaculate!

Before:

IMG_0784 (resized).jpeg

IMG_0785 (resized).jpeg

After:

IMG_0812 (resized).jpeg

IMG_0807 (resized).jpeg

IMG_0811 (resized).jpeg

IMG_0814 (resized).jpeg

Those are just clear plastic washers. I cut a little bit off one side to allow them to fit the time expander cover. I had to replace my sling plastics as well. They also have plastic washers on them but they're hard to see in that picture.

Oh, and for the dimple theorists out there....fresh dimples on a virgin 1992 Diamond Plate playfield.

504CBCEF-9885-47FE-92AA-45C9B6F6CB82 (resized).jpeg

I just made sure to push the mini playfield back as far as possible before tightening down the mounting screws. Make sure you remove the dalek reset wheel/bracket from under the playfield before you loosen the mini playfield.

I’ve always used the flour/alcohol method to remove the sticky residue. It gets really messy so I’d like to try this method. I’m removing a full playfield mylar from Dirty Harry this week. Is this the stuff to use? Any tips when doing this method?

6E3ECA50-F359-41EA-B600-8EC365D796D0.png

Thank, pinballinreno One more question. This will be my first time using naphtha. Instructions on the can say the recommended ratio is 4oz to 1 gallon water. Do you mix yours or use it straight out of the can?

78EADCB6-C8BE-4537-BBF4-D417F1C806AF (resized).jpeg

Man, I hope pinside fixes this sideways photo upload problem soon. No matter what I do on my iPhone, I can’t rotate it or delete it. Sorry guys.

EDIT: I was able to rotate it after posting it. Still, please fix this robin