Sunday, July 27, 2014

Surf Champ: blowing the GI fuse: investigation!

It has been a long time since I've talked about my little Surf Champ.  It is still here, but has been out of commission.  Why?  I started with an easy problem.  Then quickly got stuck.
On my "list of things to do," a big one was noting that the final rollover wasn't being hit.  A quick inspection and the switch was obviously bent away, so no way it could register.  I bent it back to a proper gap, went back to playing, hit all of the rollovers and... ..  FIZZLE ... POP.  Lights go out.

The switch was bent away for a reason:  When all 5 rollovers are collected, the 10A illumination circuit blows.
Wait, what?

OK so underneath the playfield, right at the back, is a bank of relays of the various scoring game states.  There are 5 relays, one for each rollover.  And a 6th nestled in amongst them, called 6B.  When all 5 other relays are down, 6B goes down and lights the spinner and the left and right rollover lanes.
But 6B isn't a coil, it is a special coilless relay.  It has a single spring and a long metal bar that spans it and the 5 other relay coils.  It pushes on them with a bit of tension, and when all 5 relays are down, that bar can be pulled in as well.

First up though, I checked all of the wiring under the PF.  If this was only occurring when 6B was active, I inspected for shorts amongst the relays, shorts and loose wires under the playfield in the areas where 6B lights things up, etc.

one of the few lights activated by 6B

All of the components connected and activated by 6B seemed to be A-OK.

While I had the playfield up I came on a critical discovery:  6B was not blowing the circuit when the playfield was up!  Ooooo that's a big clue.
It could be fine up, but then once lowered, when almost down flat, it would blow again.

The first thing I intuited was that the spinner changes position as the angle gets lower, maybe something was up with that?  6B does light the spinner for 100 points.  The spinner and associated relay all seemed to check out, but I was able to also give them some loving adjustments.

Then I checked for any dangling or loose wires under the playfield that would shift as the playfield descended, but that checked out.
so with the playfield seemingly fine, I focused on the relay itself.

This is no small thing, as the stack of relays at the back of the game are a touch imposing and rather difficult to get deep in to.  I took the playfield out and laid it suspended between a table and a loveseat, and was able to open up the rack bank and inspect things more closely.

notice the slight leaf alignment on the left
Not really knowing if a slight mis-alignment or weak connection could cause a power transfer issue (I've been astounded by less obscure things before,) I loosened the leaf stack, straightened it out, and tightened it agian.  This did not fix the problem.

Next theory was that when vertical, the gravity gives the 6B spring extra bull to bring that bar down.  When the playfield is in it's normal horizontal position, there might not be enough pull, bringing it to a poor connection.  Maybe?  Nope.
I struck down that quick little theory by having the playfield up, but then unhinging the relay bank, thus the relays would be aligned in the same manner as if the playfield was normally down.  With the playfield up and the relays down, 6B didn't blow anything, thus effectively ruling out the relay bank.

I did some testing with the alignment of the playfield, figuring how far it has to go down before the circuit goes wonky.  I even took the playfield out and lowered it mostly flat, juts away from the back of the machine, and it seemed to work then.  (that turns out to have been a fluke, and acted as a red herring in my investigations)

What was left?  Well when the playfield slides in to place there was one odd thing near the back: a big black block stuck to the wall.  Turns out this is an isolation transformer.

oh hello there, mystery box.

The power cord goes in, and the main transformer is plugged in to this one.  Turns out they were required by Ontario Hydro, back in the day, to separate machines from the central ground.  This would ensure that if something shorted internally, and someone touched this and another game, they wouldn't get high voltage through them.
This also meant that they also sucked power continuously when plugged in, even if the game (and thus main transformer) aren't turned on.  And almost nobody operates EMs outside of personal collections, so totally unneccesary.
115 in, 115 out???   stupid transformer!
My brain gurgled up a theory that HEY, maybe this transformer had an electromagnetic field, and that the 6B bar, being 6 relays wide, might be blowing the circuit when the playfield is lowered down towards this!  This theory was quickly corrected and dismissed by people that Know What They Are Talking About, but my research revealed that this still had to go.

I had to wait a while to get help taking the head of Surf Champ off to get access.  I used to think I was Ok strong since I can help move furniture around the house, but I am not Pinball Strong.  I can't lift an awkward 4-player EM head solo.  Or at least not safely.

This has got to be one of the densest things I have ever lifted!

Extracting it was fairly easy, and I spliced the external heavy duty line cord in to the meh weak one inside the machine, going in to the transformer.  Spliced, soldered, and capped.
When I sell Surf Champ, I will be happy to report the dead weight of the isolation transformer is no longer involved in the move.

But let's not forget why I was there in the first place:  No, this didn't fix this issue.
On some advice to do so, I went back to the harness with renewed vigor.  Then, 5 minutes later, I found the issue.  The issue I had spent weeks hypothesizing and spinning my wheels on.  The issue that had taken me to repair and fix a bunch of other stuff on the machine in pursuit of MAYBE THIS IS IT???

This was it:

Look at the leftmost black wire.  The shielding has rubbed through against the light bracket.  Very very very hard to see, since it's dark gray coated by black, but that is what was doing it.

Wrapped it in electrical tape, problem solved.  Played some Surf Champ.  On to a new challenge!

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