[help!] TRON - new switcher and blown fuse

[RayB]

Hey. I need advice. I just helped a local guy install a new switching power supply into his TRON. (It's a Happ Controls switcher, with a Tron MCR adaptor from ArcadeShop).

The instructions recommended tapping AC power for the switcher anywhere after the main power switch. It even suggested tapping it off the marquee light fixture. So that's what we did.

I wired the switcher to the rear florescent light input (before the filter). We figured out that BLUE is hot, BROWN is neutral and green/yellow is ground. Here's a schematic: http://www.crazykong.com/manuals/Tron.man.pdf (page 96)

Everything wired up, we powered on and I measure the AC going to the switcher and it was good (125). Measured the +5 and it read 5.01. The game itself showed nothing on the monitor and there was a repeating "thump" sound from the speakers. I figured it was the game resetting.

Now the thing about  Tron is that everything is cramped, and I don't know where to get access to a test point to measure voltage at the game board. So the best I could do was adjust the switcher power a little, then turn the power on and off to restart the game. The last couple times, I used the game board reset switch instead of powering off completely.

The second or third time I pressed the reset switch, a few blew. It's the 1.5amp fuse that is on the same line we tapped for power.

So... any ideas as to why the fuse would blow? Is tapping power that's going to a florescent light bad? Would that cause fluctuations in the AC? Where can I find a test point on the game board?

~Ray

[grantspain]

your a/c wiring is not completly correct,brown is hot,blue is neutral and green/yellow is earth but getting your a/c round the wrong way does not really cause a problem.getting your a/c from the flo tube is not perfect but should be ok.your fuse maybe slightly underated or not anti surge which might have caused to blow.the most worrying thing is the adaptor you have,you must check everthing is correct on that,and you need about 5.10volts onto the board because voltage drop-follow your 5v wire to as close to the game board you can go and check there.

[RayB]

your a/c wiring is not completly correct,brown is hot,blue is neutral and green/yellow is earth but getting your a/c round the wrong way does not really cause a problem.

What's your source for this claim?  Look at the schematic. The fuses are placed along the lines marked as "BLU". It doesn't make sense to me that a fuse would be put along Neutral lines. Shouldn't a fuse break the HOT line?

[ChadTower]

With a cab that old there's no way of knowing WTF is in there relative to the schematics anyway.

[RayB]

With a cab that old there's no way of knowing WTF is in there relative to the schematics anyway.

How about my eyes? The cab looks to be all original and untouched. Before even looking at the schematics I visually figured blue was hot. Then the schematics seemed to confirm it.  (Though now Grant thows doubt on that.)

[grantspain]

well i can only tell you how it is in the u.k cabs,and brown is always live but like i said its not that important,here in spain a/c is completley reversible so your fuse placing is not important at all.i dont think you should worry about this issue.i am sorry if i have confused the issue

[D_Zoot]

Ray,

I've got a Tron at the shop right now.  I'll have a look at mine for you this evening when I get in over there.   I'll let you know how the A/C is wired and see if it's the same.   If it's the same, then you might have a bum switcher or a problem further downstream (after the switcher).


D

[RayB]

Grant: No problemo! 

I've got a Tron at the shop right now.  I'll have a look at mine for you this evening when I get in over there.   I'll let you know how the A/C is wired and see if it's the same.   If it's the same, then you might have a bum switcher or a problem further downstream (after the switcher).

Cool, thanks. When you open up the top door, you'll see the rear floro fixture. There are 3 wires with a molex connector coming from that. That's where we tapped power from.
~Ray

[BUCKETHEAD]

Found this while reading about a TRON ,

Don't know if this applies to your situation ?



THE DREADED PURPLE WIRE:

After much frustration I discovered some info about the dreaded "reset circuit" on the power supply and the dreaded "purple wire".  Well after clipping the purple wire Tron was alive.  The purple wire is the output of the reset circuit and when the circuit fails the game thinks it is stuck in a reset.  Cutting the purple wire from the power supply board defeats the reset circuit and I was in business.  The purpose of the reset circuit it to ensure that the game will reset in case of a power fluctuation such as a brown out or power sag.

[D_Zoot]

Ray,

Okie, had a look.  Yup, it is the blue and brown wires for AC.  The switcher doesn't care hot from neutral, so you are on the right wires.  BUT, here's an issue, the fluorecent lamp circuit is sub fused at 1.5 amps, that's probably not be enough to run the lamps and the power supply at startup (a surge in current with the lights and the supply trying to start up at the same time).  You should move your AC tap.  If you look between the two transformers in the bottom of the cab you should see some terminal strips with brown and blue wires.  Those strips are the main connection points for all the switched AC lines. Those strips are after the main fuse but before the lighting sub fuse.  Try moving your switcher AC supply there.   Or, just to test the theory, unplug the flourescents and retest. 

As for the reset issue, I think Buckethead is onto something.  I've heard of that before myself but never run into it since I rebuild the original supplies instead of going the switcher route.

Good luck!
D

[RayB]

Thanks guys. Back to the "drawing board" this morning. Will report later.

[RayB]

Okie, had a look.  Yup, it is the blue and brown wires for AC.  The switcher doesn't care hot from neutral, so you are on the right wires.  BUT, here's an issue, the fluorecent lamp circuit is sub fused at 1.5 amps, that's probably not be enough to run the lamps and the power supply at startup (a surge in current with the lights and the supply trying to start up at the same time).  You should move your AC tap.  If you look between the two transformers in the bottom of the cab you should see some terminal strips with brown and blue wires.  Those strips are the main connection points for all the switched AC lines. Those strips are after the main fuse but before the lighting sub fuse.  Try moving your switcher AC supply there. 

The saga continues:

DZoot, did you mean the strip where there's 2 brown wires on the left, two blue wires on the right and two unused tabs in the middle? I tested these points and the problem with using this spot is that power still runs to them even with the machine off. You need to unplug the machine to turn power off that area.

Well, just as a TEMPORARY solution, we tapped our power from there anyways. There's a set of fuses before it, so I figured it's safe.

Welp, long story short, we had a screen full of garbage, along with that repeating "thumping" sound. Tried to adjust voltage and the power supply died in a puff of smoke.

The damn power supply has a bad potentiometer!! Just touching the knob with the tip of your finger would cause the voltage output to go nuts and we could hear static through the speakers. I think that was the cause of its death. And it's a brand new Happ Controls switcher. Unbelievable!

So now the Tron's owner is trying to get ArcadeShop to replace it.

[RayB]

PS: ArcadeShop was claiming we should tap power off the monitor's AC! But I know this is wrong, since the monitor must be isolated from everything else.

[grantspain]

PS: ArcadeShop was claiming we should tap power off the monitor's AC! But I know this is wrong, since the monitor must be isolated from everything else.

arcadeshop sold a faulty product,dont matter where it gets ac from,they should replace it without delay-cheeky sods

[D_Zoot]

PS: ArcadeShop was claiming we should tap power off the monitor's AC! But I know this is wrong, since the monitor must be isolated from everything else.

No, the monitor should be the only thing on the output side of the isolation transformer.

But that's besides the point.  Tapping into the light circuit would not have damaged the supply. 


D

[RayB]

So... latest in the saga:

Dude buys a new switcher. Installs it. Tries it out. Says smoke poured from one of the main PCBs (Trons have a 3-board sandwich).

I checked it out today, and I'm pretty sure the main harness was plugged in backwards. Looking at the board, there's a 1 inch cylinder type part, wrapped in copper, that is blackened and stinks.

If anyone has a boardset they can let go for cheap, let me know.

~Ray

[D_Zoot]

Oh man, that stinks....  (no pun intended)  !!!

Killed a working Tron boardset... yuk...


Best bet for one of those is to post over to the r.g.v.a.c newsgroup.   Good luck finding a boardset for cheap tho..   Working boards go for some $$

I might have a couple of orphan boards from some seperated stacks.  I dunno if anything works.  If he get's stuck I could have a look at his boards and *maybe* piece together something between his and what I have.  It would really come down to how much damage his boards suffered.  In a case like that it could be a little or could be widespread damage.  I'll bet there's more damaged components on that board then it would appear just from looking at it.


Regards,
D

[grantspain]

Probably stuck negative voltage up the board,if your very lucky it will have stopped at that componant,which either a coil or a cap

[RayB]

I'm pretty sure something got 12v when it should have been getting 5v. I could only find that one part that look visibly damaged (but I hear what you're saying about how other things could be damaged and not show it). If it were my board, I'd start by replacing the visibly damaged "coil thing"...

[grantspain]

if something got over volts then i am sure the problem is isolated to the componant that takes the brunt of the juice e.g that coil,but if you get a negative d/c in the wrong place you are looking at some serious poo on that board.