Time to get out of my dumbness and use that multimeter to its full potential.

Other than testing for continuity, i gotta admit i am a bit dumb with that tool...

My GnR auto-launch coil stopped working during a game yesterday and rest in peace since then.

Trigger works fine as well as the switch telling that the ball is still in the shooter lane. There seems to be no power to the coil, it does fuckall in coil testing mode.

1. How do you efficiently test that a coil is working (not fried) ?
2. How do you test the diode ?
3. How do you test that the coil actually gets power when you activate it in test mode ?
4. How do you efficiently test a fuse ? Is testing for continuity necesserely means it is good ? Or should i test for correct ampereage ? Cause PPB fuse F8 which is supposed to drive that coil appears to be ok (is testing good for continuity).
5. Any other idea on how to troubleshoot that coil other than that ? Gotta see if it actually gets power first..

Any hints appreciated, yes i am newb, never said otherwise, i'm not an engineer  

I really intend to learn thou,
THX !

Az, the lame operator (the stupid machine told me there was a problem with the shooter coil and to call the operator... cant it gives more infos  ) lol

First of all chack all the fuses on the flipper board (inside the cabinet on the left side).  TAKE THEM OUT!!!  don't test them in the holder.  there should be 3.

1. How do you efficiently test that a coil is working (not fried) ?
Coils usually don't fry/fail/die etc..  Diodes break tho...  When that happens it usually blows a fuse or transistor or both. To test a coil check continuity and resistance.  Continuity only means there's no break in the coils (good thing).  Resistance is what you should check.  Test a good coil that's the same rating first.  The resistance should be similar.  If it's very low or 0 then that coil has overheated and shorted and needs to be replaced.


2. How do you test the diode ?
Put your DMM in ohms (resistance) testing mode.  Put your probes on each side of the diode, measure, then switch the probes, measure again.  You should have 0 resistance on one check and some restistance on the other.

3. How do you test that the coil actually gets power when you activate it in test mode ?
A coil gets power ALL the time.  It fires when it gets grounded.  Connect the red terminal of your DMM to any of the lugs when game is on, and the black terminal to the grounding strap in the cabinet.  You should get voltage (whatever it may be on GNR probably around 50V if it's high power or around 25-30V if it's a regular coil..)

4. How do you efficiently test a fuse ? Is testing for continuity necesserely means it is good ? Or should i test for correct ampereage ? Cause PPB fuse F8 which is supposed to drive that coil appears to be ok (is testing good for continuity).
Like I said at the top, check the flipper board fuses.  You have to take it out of the holder (at least one side) to check it properly.  If continuity is good then it's good.. period..

Good luck

Mike

You can also check here:
http://www.marvin3m.com/de/index2.htm#flip0

Go down to the section entitled - if flippers don't work or are intermittent.
GNR is a solid state flipper game.

Mike

Thx Mike !! Why should i check the flipper board thou ?

I'm pretty sure the fuse driving it is on the PPB board, but then again, what do i know

And yes, its a 50V coil.

Thx for all your usefull info !

Sylvain

The fuse on the PPB drives the flipper board, which in turn drives the flippers.  Having a good F8 on the PPB means nothing other than the flipper board hasn't shorted out completely..

Mike

I see.. but it isnt a flipper coil, its the ball launcher, unless its seen as a flipper ?

Sorry, just want to make sure I got it thou thx, will have at least something to troubleshoot tonight, i was completely in the dark..

Sylvain

A coil rarely goes bad by itself.

Typically, a fuse, incorrect fuse rating or type, broken wire somewhere (could also be on another coil!), cold solder joint, crimp/connector, portion of power supply, switch matrix or coil drive transistor is to blame.

I have seen a few cases of diode across the coil go open or improperly soldered, thus not removing the huge voltage spike when the coil is de-energized - this usually causes the drive transistor to short-out, leaving the coil on for too long - overheating and/or fuse blows. That diode across the coil lugs could also short, but it is very rare.

I have also seen a few cases of the small wire of the coil break at the junction of the lug - in this case, the coil is opened (no continuity), and it often can be fixed if done carefully.

As Mr.Mikeman stated, testing the coil and diode is straightforward - although you may have to disconnect one end of the diode from the coil to properly test both.
http://www.marvin3m.com has good info on how to test diodes here using a multimeter:
http://www.marvin3m.com/begin/index.htm

Bonne chance!
- Sylvain @ Ottawa

F$%^..  That's what I get for trying to respond AND do my my job at the same time...  In my small brain it became a flipper problem..  

Ughhh....

The transistor is the most probable culprit IF YOU HAVE POWER!!

I've found quite a few times that the daisy-chained power wires sometimes get unsoldered on a different coil so checking power is the first thing you have to do..  

we'll go from there!

Mike

heh, will look at it indeed, looks to me as there was no power at all...

Tested power to the coil (finally got some time) and that coil gets high voltage !

Its supposed to get 50v (i tested all other 50v coils and they get around 45-46) but this one get 86 !!!

Something is up for sure, why would it get more power ? The transistor ? Something else ?

The 50v coils fuse is not blown and all other 50v coils are working as expected...

Tested transistor and its good... Did the tested the 6 possibilities and nothing reads 0, and all results are same than with the other transistors...

Sparky pointed me toward the fact that it looked like a crossed wire, just like power from somewhere else was jumping on that wire...

Grr, can i play now ??

Ok guys, i tested coil the hard way. I grounded it on the cab with an alligator clip and it fired. So the coil is working fine.

I did removed the PPB board and seen nothing suspicious, tested the TIP36C transistor good...

Now, following Marvin troubleshooting logic, i would like to short the TIP36C pre-transistor. Its supposed to be of type TIP122/TIP102. Schematics does not say where it is located thou... I have quite a few TIP122 on the cpu board, are they the ones i am looking for ?

Anyone with a Data East game able to point me toward the correct TIP122 transistor for the TIP36C Q5 on PPB board would help me a bit here...

Thx !

P.S. 86v of power with no load on the coil seems to be normal according to Marvin's site... so i guess its not the problem.

Very weird.. i did find the corresponding TIP122 chip (Q44 on cpu board) and shoerted it in diagnostics mode to see if the shooter coil was firing... it did !

So problem is elsewhere, before that in the chain....

However, doing that fixed the problem ??? The shooter coil is now working fine after 3 games !!

Problem came back again after a ball did not launched correctly, can it be a software protection thats gets resetted when you short the transistor ? I'm lost...

Shorted it again and it fixed it....  

Cold solder joint, bad connection at crimp for that wire/connector leaving the board, or intermittent drive transistor.

Shorting a drive transistor will not affect software - unless an opto/switch in the shooter coil.

Check the wiring/connectors then replace the transistor.

Bonne chance !
- Sylvain

Well intermittent transistor would work sometimes ? No ? Right now, once it failed (it shows something is wrong with shooter lane on the DMD when it happens and then its totally OFF until i short the transistor... and if the ground wire was badly crimped, why activating it via the transistor short would fix it for a while ?

Can the problem be located elsewhere ? Shooter lane switch staying on or something, or else why shorting it would always work. If it was intermittent it would be less accurate i assume..

Anyway its working for now, i sure does need to find the source of that thou. Thx for all your tips Sylvain.

Mystery is lit !!

Sounds like a driver or pre-driver transistor to me.  Sometimes these may test good and then not work properly under load.  Although the ones that I found were bad on my boards in the past tested bad.