I just got back from a house call on an F14 pinball.
The game boots up and goes into attract mode.
The owner said they smelled smoke the day it quit working.
Of course they have no manual so I need a bit of help.
Here is what I have found so far with photos.

When you first turn on the game it will blow the 4 amp fuse on this little board pictured in the backbox. It is located in the lower right hand portion of the backbox.

Also found a melted coil. It is the one in the photo. It looks to be an AL 26-1500. It is the very first diverter coil along the left edge of the playfield. I know that the controlling transistor is probably bad as well, but have no idea what transistor controls this coil.

And lastly I noticed that with the playfield raised up, on the very top left side is a small board that has a burnt and disconnected diode on it. It is show in a photo as well. What does this control and what do I need to replace it with?

I think that is about it.
Any ideas appreciated.

IMG_3433 (resized).JPG

IMG_3435 (resized).JPG

IMG_3437 (resized).JPG

IMG_3438 (resized).JPG

Thanks.
If the BR is bad, is it just the same type I have on hand for my Williams WPC games?

Thanks Grumpy.
That is just the information I was hoping for.
I have not tried powering on the game after I cut the coil leads. But I will after the new coil arrives and I get back over there next week.
Thanks for the Q77 and Q79, that is exactly what I was hoping for even though I could get it with Loyds manual link.
Never heard of a snubber relay board, but this game is loaded with them. I will definitely replace that resistor with the correct value.
Also love the idea of removing the single fuse for high current to find out if it is a board or coil issue.

Awesome. All I keep on hand are TIP 102's for this very reason.

Been awhile on this one because of spring break and TPF.
But I replaced Q77. It was so bad it had black crud leaking out of it. lol
But after turning on the game with a new TIP 102 installed the coil still pulls in at power up.
I am guessing it is the little smaller transistor right above Q77 that must be bad as well.
Does that sound correct?
Other then upper diverter coil sticking on, the game is playable now. So once I get this problem solved we should be good.

Thanks for the replies.
I am sitting at the board now with my meter.
All the TIP 122 in this section measure .669 across the two outer legs.
The new TIP 102 I installed measures only .369
Does that sound correct or am I missing something else? The little 2N resistor above it reads .369 as well.

Photo of the area. Q77 is the center front.

IMG_3641 (resized).JPG

Thanks Grumpy.
Been awhile since I have done something like that. So I can just put red end of lead to pin 1 of the 7402 and the black to a ground test point on the board?

My biggest issue is distance. I can only check the board at the guys house
Then drive back to install new 7402 on my workbench.
Looks like this could take some time to figure out.
I looked in my parts bin and I do have a spare 7402 on hand though.

I have both a pc power supply and idc connectors.
What would go where?
Interesting

Thanks.
And yes the batteries are no problem.

here is something I found from an online guide.

But don't want to mess with something like this without guidance.
Certainly need to know if I need to ground this in any way.

Here is what I found online.

Hook up the power supply to the CPU board using aligator clips. Here's the pinout for the power connector 1J17 on the CPU board.

Pins 1,2,3 = ground
Pins 4,5,6 = +5 volts DC
Pin 7 = key (not used)
Pin 8 = -12 volts DC (only used for audio, IGNORE)
Pins 9 = +12 volts DC

My power supply powers up as soon as I plug it in.

Can I just leave the board on my Wooden table and put an idc on 1J17

Ok. I will post a photo of what I think needs to happen after dinner if I have time to try this tonight.

Yea. I saw that -12 was only for sound .
I am going to whip up a connector and test the voltage in awhile.
I'll post a photo before I hook it up

Ok. My 5 volts from the power supply measure 5.28 volts
My 12 volts only measure 11.28 volts.
Is that good enough for this application?

So loop one red wire through 4,5 and 6?
Can I loop ground through 1,2 and 3?

Maybe I am misunderstanding what I should loop. Pins 4,5 and 6 all need 5 volts.
Why not just run separate 5 volt wites to each pin? I have so many. Lol

Ok. I'll loop one and run a second wire to the other. That should get all 3 pins

Ok here we go. Photo with power supply off.
I have 5 volts on pins 4,5 and 6
And 11.28 volts on pin 9

Any glaring mistakes?

IMG_3642 (resized).JPG

I'll be damned it works

Any way my 7402 pin one reads 0.10 volts.

Is that good and anything else I can test?

Attract mode.
It locks on as soon as the power is turned on.

Ok great.
Hate to ask so many questions but do I check voltage on both sides of R 102 with the power going and grounding each side to the ground point on the board?

But I agree it is most likely the 2N 4401.
That is what I would have changed if I were just guessing.
But your help here has been over and above. Thanks a million

Ok.
One side of 102 is 0.00
The other side closest to q76 is 1.32 volts.

Thanks.

Done. Now both sides of R 102 are 0.00

Now I do have the meter set on 20 volts.
I also have a 2 volt setting and a 200m

Crash course in resistance please.

None of the settings in my meter measure anything from ground to the top of the metal tabs

This is the meter I have on hand.

IMG_3649 (resized).JPG

That is the 20M setting.
I still get no reading tab to ground.

However I also found this meter if that helps.

IMG_3650 (resized).JPG

Set new meter to omega symbol.
I get readings ranging from 5 to 11 on all 6 tabs

The 11 is from the new TIP 102 I installed.
The 122's are around 5 or 6

Good. I will just have to try the board now.
This test is all over the map. Sometimes I get around 1500 and sometimes I get no reading at all.
And oddly enough as I move the meter around the tabs some that were reading the first go round refuse to read anything just seconds later.
Maybe my meters are just poor but I don't trust any reading I am getting with this test.

Success!!
Game is up an running.
Thanks again for everything.