5 Lights out on WMS 550

[Hokiehog]

I have five lights out on a Jackpot party.  Has anyone run across this problem? 

I reseated the boards to no avail.  Any ideas?  I'm a newbie so be gentle.

[jdkmunch]

You swapped the bulbs and it still doesn't light?

[tacman]

Actually I would first suggest popping off the clear button cover and using a thin neednose plier, pull the bulb and then reseat it back in the switch. My 550 buttons go out sometimes and this has worked without a bulb replacement. I think they get jostled when you open and close the door. But then again you may need new ones!

 Dan (tacman)

[Hokiehog]

I already swapped bulbs from working and non-working locations.  The lights themselves are fine.

This appears to be a deeper problem, I eliminated the obvious before I began begging for help

[jdkmunch]

how about swapping the wiring from a button that is out to one that is on?

[cfh]

whenever there's a lamp problem on wms slots, you need to
use the lamp matrix test. they use a 8x8 matrix of 8 rows and
8 columns for the matrix. this is done using TIP102 (columns)
and TIP107 (row) transistors on the slot I/O board.

Using the lamp test you can figure out if all the missing lights
are in the same row or column. i would suspect they are.
the display will say "r1c3" (meaning row1 col3).
then you can use the schematics and figure out which TIP
transistor controls that row or column. These TIPs can be
tested with a DMM set to diode function to verify whether
it's dead or not.

also rows and columns "daisy chain" from each switch.
if the chain is broken "up stream", all the lights "down stream"
won't work. This may be the case in this situation.

It's really pretty straight forward stuff.

[Hokiehog]

how about swapping the wiring from a button that is out to one that is on?

Tried that... Same result - Lights up on the swapped one - other stays dark

[Hokiehog]

whenever there's a lamp problem on wms slots, you need to
use the lamp matrix test. they use a 8x8 matrix of 8 rows and
8 columns for the matrix. this is done using TIP102 (columns)
and TIP107 (row) transistors on the slot I/O board.

Using the lamp test you can figure out if all the missing lights
are in the same row or column. i would suspect they are.
the display will say "r1c3" (meaning row1 col3).
then you can use the schematics and figure out which TIP
transistor controls that row or column. These TIPs can be
tested with a DMM set to diode function to verify whether
it's dead or not.

also rows and columns "daisy chain" from each switch.
if the chain is broken "up stream", all the lights "down stream"
won't work. This may be the case in this situation.

It's really pretty straight forward stuff.

Not to be retarded, but what is the "lamp matrix test"

The only lamp test I have seen cycles thru the lamps.  Where is this test at?

[StatFreak]

whenever there's a lamp problem on wms slots, you need to
use the lamp matrix test. they use a 8x8 matrix of 8 rows and
8 columns for the matrix. this is done using TIP102 (columns)
and TIP107 (row) transistors on the slot I/O board.

Using the lamp test you can figure out if all the missing lights
are in the same row or column. i would suspect they are.
the display will say "r1c3" (meaning row1 col3).
then you can use the schematics and figure out which TIP
transistor controls that row or column. These TIPs can be
tested with a DMM set to diode function to verify whether
it's dead or not.

also rows and columns "daisy chain" from each switch.
if the chain is broken "up stream", all the lights "down stream"
won't work. This may be the case in this situation.

It's really pretty straight forward stuff.

Sounds like the same design pinball machines use.

[cfh]

yes it is the same lamp design used in their pinballs.
that's why there's 8 TIP102 and 8 TIP107 transistors
on the slot I/O board.

The test that cycles through each of the lights individually
is the lamp matrix test. just note which r/c numbers are
the lamps not being lit, and report back here. (there is also
a "all lamps" test too, but that does not tell us the individual
row/column numbers of each lamp, which is the information
we need).

[Hokiehog]

yes it is the same lamp design used in their pinballs.
that's why there's 8 TIP102 and 8 TIP107 transistors
on the slot I/O board.

The test that cycles through each of the lights individually
is the lamp matrix test. just note which r/c numbers are
the lamps not being lit, and report back here. (there is also
a "all lamps" test too, but that does not tell us the individual
row/column numbers of each lamp, which is the information
we need).

It appears to be the Q9 row that is failing. (Blue / Yellow) is the common wire that is on that group

I am going to take it apart later (whenever my wife gets off of the machine later tonight) to see if anything is grounding it out in the back of the backplane.  Any other suggestions are more than welcome.  I'm willing to learn from everyone

Thanks

[Hokiehog]

I also pulled out the IO board and there are no burn traces or obvious issues on the board.

My next and probably last effort will be to pull out the backplane and see if anything got lodged in there during transport.   

[cfh]

Ok so you have found the common wire between all the
non-working lights. that's the row or column in the lamp
matrix that is causing problems. so what you need to do
is find the FIRST bulb that uses this wire. Get the game into
lamp matrix test, and get the game to think it's pulsing that
(non-working) lamp.

Now take a logic problem and put it on this wire. Do you
get a high-low-high-low pulse? probably not. now back up
the logic probe to the backplane board, where that wire
comes out of the board at J13 (beneath the CPU/IO board,
left connector). put the probe right on the J13 backplane
where the wire comes out of the connector,
and see if it's pulsing there.

If you get a pulse on the J13 backplane, then you have a broken
wire issue. no pulse on the backplane, and you have a
broken trace or transistor problem.