My new ROBOTRON! working again (woot!)

[Q*Bert_OP]

The title says it all...my power supply voltage spiked up during a game, smoke pours out of the back from the pcbs...

F*CK

F*CK

F*CK

F*CK William's Power supplies!!!!

 

[Q*Bert_OP]

$550 down the drain up in smoke

[leapinlew]

You have my condolences...


 

[Q*Bert_OP]

the thing that really pisses me off is that I just got it this past Saturday, and that I have only played it about 30 times

[NightGod]

Ouch. That sucks hardcore.

[Ken Layton]

Was the power supply rebuilt? Did it have new connectors installed?

This is exactly the reason I like to yard out the original power supply and convert the cabinet to use a switcher instead.

[MaximRecoil]

$550 down the drain up in smoke

Make that $542.50...

Seriously though, Robotron boardsets aren't that expensive are they? If you rationalize it to yourself that it would have been a good idea to convert it to a switching power supply either way, then the only thing you are out is the cost of a replacement board, right? I don't know what those boards go for, but I wouldn't think it would be $550.

[MYX]

Also the whole thing may not be toasted either. Was it your house power that spiked or the game? How do you know?
I wpi;d pull the boards and look for visible sines of damage. Also a fried chip will smell like rotten eggs, sounds silly but sniff around the board.

Does the game do anything at all right now?

Like Ken said (cause he is the man!) get a switching powersupply in there first before you do anything else.
Then If you have the skillz, (and the time) then pull the board and start to trace it out. It will take a while but it can be done. If there is a big black circle burnt through the main board then... you may be up the creek.

But even if you do opt for new boards, get the new PS no matter what.

I am sorry, Robotron is a rockin game. One of my favorites. 

[Ken Layton]

Usually it's the bank of ram chips (socketed!) that cook.

[Texasmame]

Was the power supply rebuilt? Did it have new connectors installed?

This is exactly the reason I like to yard out the original power supply and convert the cabinet to use a switcher instead.

Yeah, you really need to convert the old PS to switchers in just about ANY game, just in case.  Heck, if the PS is working when you get a game, eBay it and you might even MAKE money in the end! 

[RayB]

Don't say that man! I like to keep my Ataris original!
 

[ChadTower]

Me too.  Rebuild the AR board, replace the big blue, repin the connectors and the PS will run another 20 years.

[Texasmame]

Don't say that man! I like to keep my Ataris original!
 

Yeah, I know there were guys who were into the "all original" thing.  Me, I just wanted stuff that would WORK all the time (if possible) for the insides.  Had a few switchers in my games and it didn't bother me one bit. 

Now, on the EXTERIOR, I always went for original stuff, with the exception of a couple repro overlays I had for Stargate and Centipede. 

[Q*Bert_OP]

$550 down the drain up in smoke

Make that $542.50...

Seriously though, Robotron boardsets aren't that expensive are they? If you rationalize it to yourself that it would have been a good idea to convert it to a switching power supply either way, then the only thing you are out is the cost of a replacement board, right? I don't know what those boards go for, but I wouldn't think it would be $550.

Nah, That $550 is what I payed for the machine...

[Q*Bert_OP]

bad resistor smoked...replaced...now working (woot!)

[ChadTower]

All of that drama over one resistor?

[Lutus]

Sometimes it is pleasently simple.  Comically simple in fact.   

[danny_galaga]

bad resistor smoked...replaced...now working (woot!)

huzzah!

[ChadTower]

Well, simple for now, until the resistor fries again because he didn't track the cause.

[Stingray]

bad resistor smoked...replaced...now working (woot!)

Excellent!

-S

[Ed_McCarron]

Well, simple for now, until the resistor fries again because he didn't track the cause.

You are starting to sound like Marvin.

Is it not a possibility the resistor failed because it was old?

[ChadTower]

Not if it burst into flames.  They fail when they get old, yes, but they don't freakin explode.  The only way they burst into flames is when something overloads them. 

[Q*Bert_OP]

I'll still get a swithching power supply in there...

[Texasmame]

I'll still get a swithching power supply in there...

Good man.   

Don't delay on that!  The machine has given you fair warning already! 

[ArcaMan]

Ok, I sound stupid, but what is a "switching powersupply?" .... I just inherited a Robotron that was litterally in the trash and my neighbor saved it for me. (I owe that guy a KEG of beer for his kindly thinking of me!)

Oddly enough, the guy apparently chose to replace it with the Target cabinet.  I can't imagine downgrading from a working Robotron to a half assed one, but I am glad he passed the Robotron on to me

I am 90% certain that at least part of the problem is the power board because the person said that it "stopped working suddenly" and only 2 of the 3 LEDs are lit. (hoping it is just a matter of getting a new fuse!).

Anyhow, while I am doing the whole restore and clean up (also needs new bulbs for the marquee and one of the coin returns), I figure I'll also upgrade what ever might cause probs in the near future.



James

[BUCKETHEAD]

This is a Switching Power Supply,

[SirPeale]

Ok, I sound stupid, but what is a "switching powersupply?" .... I just inherited a Robotron that was litterally in the trash and my neighbor saved it for me. (I owe that guy a KEG of beer for his kindly thinking of me!)

Man, what a find!  I can't believe he was going to bin it!

[ArcaMan]

Thanks for the picture, I was more interested in ...

1. What does it do ... why is it worth upgrading?
2. What one do I need for a Robotron (also I probably need one for my Op Wolf that I am slooooooowly restoring by combining two cabs that I rescued and hoping I have one set of working parts between them )

I wasn't sure if PSUs are like they are on PCs i.e. almost all the same, just different wattage or if I need game / manufacturer specific ones.

BTW sorry for sorta hijacking the thread, but it looked like the original poster and I had / are having a similar experience

James

[RayB]

It's a modern power supply used in almost ALL arcade games. Puts out +5, -5, +12 voltage. More reliable than the old setup.

[CheffoJeffo]

If the "2 out of 3 LEDs" refer to the Wlliams power supplyboard, then it could be as simple as a blown fuse. Of course, you'll want to know WHY the fuse blew in the first place.

ArcadeShop has these nice easy adaptor boards that you screw into a switching PS, then plug the Williams power harness into. Literally a 10-second job:

http://www.arcadeshop.com/pics/wms-ps.jpg

Cheers.

[ArcaMan]

Yeah, that is exactly where the LEDs are located.  LED 1 is off, the other two are on. I"ll check that thing on arcade shop out.

Thanks,

James

[ArcaMan]

Well, I tested it out (took the fuses out of the sound board and put them into the blown fuses place on the power supply board).

Game booted and promptly blew (because the fuses weren't the right strength).

So that basicly confirms that the immediate problem was the fuses.

My friend who was looking at it / testing it with me suggested that probably the fuses were just "old" and they can sometimes lose their vacume, so that may have been the problem.

also, btw it looks like this may have been one of the original games ... the inspection marks say April and May of 82 (cab and later on the CP).  A parts manual I found was published in May of 82, so I am wondering if maybe this was in the first batch.

[SirPeale]

Fuses aren't like light bulbs; they aren't vacuum sealed.

You can actually run a properly operating device for a bit on a fuse that's underrated.  Depending, of course, on just how under rated the fuse is.  Say if you're drawing 3A, and you have a 2A fuse in there, you'll be okay for a while, but if it's drawing 3A, and you have a 1/4A fuse, likely it'll toast rather quickly.

I suspect other issues.

[ChadTower]

It is other issues.  Peale's answer is exactly right.

There's rarely, and I mean rarely, any issue that is "simply a blown fuse".  Fuses almost never blow without reason.  They aren't vacuum sealed, they are a tiny exactly rated conductor protected inside glass.  Fuses are sometimes bad right out of the box but if they were ever good they don't just blow without cause.

Putting in the wrong fuses is not really going to get you much.  If the fuse is more than a little lower than the rating, it will blow immediately.  If it's higher than you're going to do more damage than good.  It won't blow at all and something further down the line will fry.

[_) (V) (-)]

On more than one occasion I have actually seen a fuse melt the solider off the inside of the end cap and open the circuit. Upon visual inspection, the suspect fuse 'looked' good and had to be tested with a DVOM to verify the problem.

[ChadTower]

Never eyeball a fuse to see if it's good.  Too often they look fine but are no good.

Anyone working on a board should know how to use the continuity check on a DMM.

[RayB]

I don't. How do I test a fuse?

[Texasmame]

Set your multimeter to test for CONTINUITY.  Place one lead on one end of the questionable fuse, the other lead on the other end.  No "beep" or whatever your meter does to denote continuity, then the fuse is bad.  Best done with the fuse out of its holder or whatever it's connected to - on its own.

[ChadTower]

It's simpler than that.

Set DMM continuity.

Touch two things.  If they are connected with near zero resistance, it will beep or display something like SHORT. 

If they are not connected, it will not beep or it will say something like OPEN.

[Texasmame]

Not if it burst into flames.  They fail when they get old, yes, but they don't freakin explode.  The only way they burst into flames is when something overloads them. 

Or when they're in a G08.