TECH: Problem with Stern Playboy. Q1 keeps frying.

[Guest]

Archived from groups: rec.games.pinball (More info?)

I'm working on a local 2002 Playboy. When I first started on it, Q1
was dead and wouldn't pop a ball up out of the trough. I got the
appropriate component from looking up what Stern listed on their
website (this was in 2003). I replaced Q1 and the game ran fine for a
few weeks. It then fried Q1 *again* and I mean FRIED! It melted
part of the surround off the transistor, left smoke trails on the PCB
and it looks like it took out C270 next to it as well.

My question to all of you is two fold:

#1 What should I be replacing that component with? The one Stern
recommended was expensive for a power triac and didn't last very long.

#2 Why would this thing fry again? What would be wrong under the
playfield that could be causing it to fail?

Oh, if you're wondering why I waited so long to fix it, the owner had
put it in storage and just now drug it back out to fix!

Gary Martin
Lawrence Kansas

 

[Guest]

Archived from groups: rec.games.pinball (More info?)

I would first start by verifying you have the
correct fuse for this coil. It sounds like the
game is overfused, as this shouldn't happen.

Replace with the correct part and check the resistance
of the coil.

fred
TX
CARGPB#8
==========================

Gary Martin wrote:

> My question to all of you is two fold:
>
> #1 What should I be replacing that component with? The one Stern
> recommended was expensive for a power triac and didn't last very long.
>
> #2 Why would this thing fry again? What would be wrong under the
> playfield that could be causing it to fail?

 

[Guest]

Archived from groups: rec.games.pinball (More info?)

There's a few different ratings of MOSFETs for current/voltages- much like
the TIP120-122 type transistors have in other brands of games. We carry the
20N10L MOSFET for use in Stern, Sega, and Gottlieb games. You may want to
check and see if you replaced your's with a lower-rated one that just
couldn't hold up as well for the application.

Aside from that, the most common things that "nuke" these are shorts in the
circuit- when the MOSFET switches full current (due to a short) it will kill
itself. A short like this is usually caused by a shorted diode- which can
be caused by hooking the wires up on the coil backward (hot wire always goes
to cathode end of diode), or from having an open diode, or a diode that
falls off the coil or otherwise comes looes/opens up.

So check for these possibilities.

You may also have a coil that has too low resistance- thus letting too much
current through for the MOSFET to handle. Check to make sure you have the
right coil. You may also want to replace the coil in case it's partially
shorted internally... Always possible.

Ray J.
--
Action Pinball & Amusement, LLC
Salt Lake City, Utah USA
Web: www.actionpinball.com

We're serious about pinball. Anything else is just for fun!



"Gary Martin" wrote:
> I'm working on a local 2002 Playboy. When I first started on it, Q1
> was dead and wouldn't pop a ball up out of the trough. I got the
> appropriate component from looking up what Stern listed on their
> website (this was in 2003). I replaced Q1 and the game ran fine for a
> few weeks. It then fried Q1 *again* and I mean FRIED! It melted
> part of the surround off the transistor, left smoke trails on the PCB
> and it looks like it took out C270 next to it as well.
>
> My question to all of you is two fold:
>
> #1 What should I be replacing that component with? The one Stern
> recommended was expensive for a power triac and didn't last very long.
>
> #2 Why would this thing fry again? What would be wrong under the
> playfield that could be causing it to fail?
>
> Oh, if you're wondering why I waited so long to fix it, the owner had
> put it in storage and just now drug it back out to fix!
>
> Gary Martin
> Lawrence Kansas

 

[Guest]

Archived from groups: rec.games.pinball (More info?)

Call 1-800-kickers and be sure you are replacing it with the right Q1. When
you put in the new one, check the traces, through and across board
continuity. I had a hairline crack in a trace that about drove me nuts.
Worked fine and then when one leg would go open it would fry the transistor.
LTG

"Gary Martin" <Gary.Martin2@gmail.com> wrote in message
news:ca61ea3b.0507211020.2cbd0fbe@posting.google.com...
> I'm working on a local 2002 Playboy. When I first started on it, Q1
> was dead and wouldn't pop a ball up out of the trough. I got the
> appropriate component from looking up what Stern listed on their
> website (this was in 2003). I replaced Q1 and the game ran fine for a
> few weeks. It then fried Q1 *again* and I mean FRIED! It melted
> part of the surround off the transistor, left smoke trails on the PCB
> and it looks like it took out C270 next to it as well.
>
> My question to all of you is two fold:
>
> #1 What should I be replacing that component with? The one Stern
> recommended was expensive for a power triac and didn't last very long.
>
> #2 Why would this thing fry again? What would be wrong under the
> playfield that could be causing it to fail?
>
> Oh, if you're wondering why I waited so long to fix it, the owner had
> put it in storage and just now drug it back out to fix!
>
> Gary Martin
> Lawrence Kansas