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EM Tech: Playfield GI fuse blows inconsistently?
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Frank G
Mar 12, 2013, 1:17:51 AM3/12/13
to
This one has me baffled ...The game is Fire Queen which I recently set
up after some time in storage. It will play fine for sometimes 10
minutes, 20 minutes, even longer, but eventually the GI fuse blows -
no playfield lights! I've also started a game and just left it with
the ball in the shooter lane. Sometimes the lights stay on for a long
time (over 30 minutes) before blowing the fuse and sometimes it takes
2 minutes and it's even been on for hours WITHOUT blowing?
With the playfield up, I simulated a bunch of different scenarios like
one bank of targets down, both down, different bonus levels lit up etc
but found no fault pattern - that is, the fuse eventually blew in
every scenario. I visually inspected the GI Jones Plug, light sockets,
daisy chain and Bonus Stepper but found no wires touching/shorting. I
also changed the fuse holder.
The only thing I did prior to setting it up, is I had the motor board
out of the game for basic cleaning/ servicing as it's way easier on my
back. I also serviced the Bonus Stepper (located under the playfield)
- it was sluggish.
Should I replace all the lights and blow out every socket with
compressed air? Should I go back and check everything again? ... or
have I missed the obvious? Does anyone have any ideas on what I should
be doing next to help me end this madness.
Tomorrow's another day. Any help or suggestions would be GREATLY
appreciated.
frankg
up after some time in storage. It will play fine for sometimes 10
minutes, 20 minutes, even longer, but eventually the GI fuse blows -
no playfield lights! I've also started a game and just left it with
the ball in the shooter lane. Sometimes the lights stay on for a long
time (over 30 minutes) before blowing the fuse and sometimes it takes
2 minutes and it's even been on for hours WITHOUT blowing?
With the playfield up, I simulated a bunch of different scenarios like
one bank of targets down, both down, different bonus levels lit up etc
but found no fault pattern - that is, the fuse eventually blew in
every scenario. I visually inspected the GI Jones Plug, light sockets,
daisy chain and Bonus Stepper but found no wires touching/shorting. I
also changed the fuse holder.
The only thing I did prior to setting it up, is I had the motor board
out of the game for basic cleaning/ servicing as it's way easier on my
back. I also serviced the Bonus Stepper (located under the playfield)
- it was sluggish.
Should I replace all the lights and blow out every socket with
compressed air? Should I go back and check everything again? ... or
have I missed the obvious? Does anyone have any ideas on what I should
be doing next to help me end this madness.
Tomorrow's another day. Any help or suggestions would be GREATLY
appreciated.
frankg
Joe Grenuk
Mar 12, 2013, 1:53:01 AM3/12/13
to
Assuming you've done all the visual insprection of looking for tabs
bent together, a socket touching something it shouldn't,etc, there are
lots of ways...since it's an EM the old school way to find it is quick
and effective. And fun. put a bolt in the fuseholder. Fire up the
game. Watch for smoke. Then, you've found the short.
A modified version is to cut the game off after a minute and feel the
bare wire or the sockets. The hot spot is the short.
You can also break the PF GI up into sections by cutting the bare
wire. Start with the GI closest to the fuse, and then follow the bare
wire maybe 6-8 bulbs and cut the wire at the lug of a lamp. Fire up
the game. No blow, resolder and go another 6 0r 8 bulbs into the
string. Fire up, no blow, repeat. If it blows you know it is one of
the sockets in the area you just carved out. If necessary, you can cut
the section in half again and repeat.
Last,Mark Clayton gave me a great lesson about this about 5 years ago:
Take one of your blown fuses and solder a bayonet lamp
socket across it using short wires. Install a #44 or #47
bulb in the socket. Now install this modified fuse in the
GI circuit with the short. Remove all of the bulbs in the
shorted string.
Now, turn on the game. If the bulb across the fuse
lights at full brightness, you still have the short, but
no fuses will blow. Now you can trace the shorted
string of lamps and start jiggling wires and sockets.
If the lamp flickers, you've found where the short is.
Jiggle a bulb in the sockets one at a time, looking
for flickering.
If you can't get the lamp to flicker, then get out the
DVM. Set it for VOLTS not OHMS and measure the
voltage across each socket. The lower the voltage
in the socket, the closer you are to the short. But
once you pass the short on the string, the volts will
go no lower. So find the first place from the fuse with
the lowest voltage and you're right next to the short.
In most cases, cutting wires is not required.
Joe
bent together, a socket touching something it shouldn't,etc, there are
lots of ways...since it's an EM the old school way to find it is quick
and effective. And fun. put a bolt in the fuseholder. Fire up the
game. Watch for smoke. Then, you've found the short.
A modified version is to cut the game off after a minute and feel the
bare wire or the sockets. The hot spot is the short.
You can also break the PF GI up into sections by cutting the bare
wire. Start with the GI closest to the fuse, and then follow the bare
wire maybe 6-8 bulbs and cut the wire at the lug of a lamp. Fire up
the game. No blow, resolder and go another 6 0r 8 bulbs into the
string. Fire up, no blow, repeat. If it blows you know it is one of
the sockets in the area you just carved out. If necessary, you can cut
the section in half again and repeat.
Last,Mark Clayton gave me a great lesson about this about 5 years ago:
Take one of your blown fuses and solder a bayonet lamp
socket across it using short wires. Install a #44 or #47
bulb in the socket. Now install this modified fuse in the
GI circuit with the short. Remove all of the bulbs in the
shorted string.
Now, turn on the game. If the bulb across the fuse
lights at full brightness, you still have the short, but
no fuses will blow. Now you can trace the shorted
string of lamps and start jiggling wires and sockets.
If the lamp flickers, you've found where the short is.
Jiggle a bulb in the sockets one at a time, looking
for flickering.
If you can't get the lamp to flicker, then get out the
DVM. Set it for VOLTS not OHMS and measure the
voltage across each socket. The lower the voltage
in the socket, the closer you are to the short. But
once you pass the short on the string, the volts will
go no lower. So find the first place from the fuse with
the lowest voltage and you're right next to the short.
In most cases, cutting wires is not required.
Joe
FredMaine
Mar 12, 2013, 6:24:06 AM3/12/13
to
Wow Joe, that's the most helpful list of stuff I'd never have thought
of. Excellent.
--
FredMaine
This USENET post sent from http://rgparchive.com
Joe Grenuk
Mar 12, 2013, 9:16:46 AM3/12/13
to
Awww shucks, Fred.
:)
:)
sbari...@gmail.com
Mar 12, 2013, 9:30:23 AM3/12/13
to
Frank G
Mar 12, 2013, 12:01:31 PM3/12/13
to
socket approach first. The 'flickering light' will hopefully identify
the culprit which a 5A circuit breaker can't do.
I've already tried jiggling wires and sockets with all the lamps
installed in the circuit and could never get it to blow - maybe I
missed one or two? The frustrating part is sometimes it blows in 5
minutes and sometimes it takes 30 minutes.
It seemed to 'often' blow when the 5k and or 10k bonus light was lit
during game play so I de soldered or disconnected those lamps but it
kept blowing.
Thanks again and I'll post my results hopefully tonight.
frankg
Joe Grenuk
Mar 12, 2013, 2:17:08 PM3/12/13
to
One other one I have been waiting for the opportunity to test, and
that is one of those laser thermometers that cost under $20 and that
you point at something and it reads out the temp of the object. I
haven't had a good GI short in a long time, but that's going to be
plan A next time one arises.
I'm thinking it will work good with the bolt trick, too :)
Joe
that is one of those laser thermometers that cost under $20 and that
you point at something and it reads out the temp of the object. I
haven't had a good GI short in a long time, but that's going to be
plan A next time one arises.
I'm thinking it will work good with the bolt trick, too :)
Joe
Gott Lieb?
Mar 12, 2013, 2:30:48 PM3/12/13
to
After recently working on a Vulcan, I would start looking at the white
lamp sockets in front of the drop targets. Either these or the star
rollover lamp sockets.
Jim
lamp sockets in front of the drop targets. Either these or the star
rollover lamp sockets.
Jim
Frank G
Mar 12, 2013, 9:11:44 PM3/12/13
to
On Mar 11, 11:53 pm, Joe Grenuk <jgre...@aol.com> wrote:
Removed every bulb on the playfield, installed the mod fuse and
started a game - first thing I noticed was the lamp wasn't that
bright. Began with juggling wires and sockets and nothing. Then I
inserted a bulb in a socket and the light got brighter - every time,
no matter what socket I put it in!
This tells me that the common daisy chain (blk-whi ) wire must be
shorting/touching against something if it affects every bulb, right?
checked and re checked the chain but can't see any problem.
Any suggestions guys. Thanks for now
frankg
flynn...@yahoo.co.uk
Mar 13, 2013, 6:41:06 AM3/13/13
to
> OK, rigged up the modified fuse with the bayonet socket and #44 lamp.
>
> Removed every bulb on the playfield, installed the mod fuse and
>
> started a game - first thing I noticed was the lamp wasn't that
>
> bright.
>
Here's your problem Frank. With no bulbs in any sockets the fuse lamp shouldn't be on at all as the circuit should not be drawing any current. You have a short somewhere that isn't quite enough to blow the fuse immediately but at some point - either due to vibration or heat expansion or whatever - is becoming a full on short and popping the fuse.
>
> Removed every bulb on the playfield, installed the mod fuse and
>
> started a game - first thing I noticed was the lamp wasn't that
>
> bright.
>
> Then I inserted a bulb in a socket and the light got brighter - every time,
>
> no matter what socket I put it in!
GI shorts are a complete pain in the arse:-) Unless you get lucky there's really no other way than to to do what Joe said.
Andy
Frank G
Mar 13, 2013, 11:22:44 PM3/13/13
to
removed but forgot the 2 in the pop bumpers. Soon as I removed them,
the bulb in the mod fuse went really dim or barely on. Jiggled and
prodded all the sockets and wires - nothing. Inspected all the sockets
once again and started inserting NEW bulbs. Put the 5A breaker in and
played tons of games - problem solved ... must have been a shorted
bulb?
Just when you think you're getting decent at fixing these games you
get a curve ball thrown at you! It was a good learning experience.
Thanks guys!
Mike Berger
Mar 14, 2013, 7:37:20 PM3/14/13
to
I had the same problem. Check the light sockets UNDER the lower apron. One of the sockets had twisted and was shorting out the circuit.
Mike
Mike
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