Double Axle repaired, or how to fix a Hantarex power supply

[Level42]

Guess most of you could care less, but I bought a dead Double Axle cab (http://www.klov.com/game_detail.php?letter=D&game_id=7615) some time ago. It was dead, and the price was adjusted because of that, but I was pretty convinced I could repair it.

The problem seemed to come from the power supply which gave a high pitched sound. So I thought, well easy enough, I put in a PC power supply and presto.....well not exactly.

This cab uses a Hantarex US250 Power Supply. The special thing about it is that it supplies everything in the cab (well not really everything, the force feedback seems to have it's own supply). However, it provides a swtiched mains for the marquee and sound, the usual 12V and 5V voltages for the PCB's but also (!!!) 135 V DC for the monitor. And this of course was the problem, I could not simply replace the supply, since no other supply I know provides a voltage like that.

So I had to fix the supply itself. The mains to the marquee worked, and also I could hear the static of the monitor when turning it on, so I figured the 135 V was ok.

Pretty soon I found the schematics on the internet, and by measuring I found out that the SCR (thyristor) that protects the output voltage of the 12V and 5V was dead. I was unsure if that was the only thing, checked a couple essential parts but they all seemed ok. Bought me 2 new thyristors (you never know) for a couple of Euro's and replaced it. I turned on the unit and.....it worked !!

I was very glad because I feared that maybe a problem on the PCB had caused the blow-up of the thyristor, but this was not the case. However. the thing was that I soon discovered the real cause of the blow-up: I had not re-connected a fan, that was places on top of the monitors' LOPT. So I figured I would now re-connect it, and turned on the unit again.    There was that familiar bad high pitched sound again, and I knew I needed my 2nd thyristor

The fan was dead, or unable to move anymore, so apparantly it shorted out the fan supply voltage, so blowing up the thyristor (why don't fuses do what they are supposed to at those times ?).

Anyway, still need to replace the fan, I also wonder why there's a fan on the LOPT ? Normaly this fan connection is for a fan placed on the power supply itself (US300 ?) so it can deliver more amps I guess...

Anyway, learned something again, and it's so much fun to play a proper arcade game at home for the first time. Of course Double Axle is not exactly a classic, but the cab is in very good condition, as well as the monitor, no burn in, clear colors and focus is still very good too. Guess this unit didn't make too many hours.

The real fun part is the force feedback, I expected it to be somewhat like the regular steering wheels we all know, but I was in for a surprise at my first test drive.
This unit is shaking the whole wheel up and down like crazy when activated ! It's not just some tiny rumble in the wheel itself.
 The wheel by the way is a full 360. There's a shifter with turbo button, and the pedal is microswitch.
In the future I might give this unit a Mame PC with lots of racing games but for now, it will stay a Double Axle.

My unit is better than the one on KLOV by the way, mine still had the original glass with instructions etc.

Ok bored you guys enough, here's a pic:

[fredster]

Pretty.  Looks nice, and you did a great job of troubleshooting and thinking! We need more of that in this world!

Omron makes about any power supply you want or need for industrial applications.
If it's not your standard Peter Chow.  Look here and see if you can get one that has the wattage you need - http://oeiweb.omron.com/Products-PowerSupplies.shtm

[Ken Layton]

If the monitor was also a Hantarex, then the fan over the flyback is there because this chassis gets very hot in operation. The fan keeps the horizontal output transistor, the flyback itself, and several capacitors cool (bad design to allow such heat buildup that requires a fan).

[mccoy178]

Good work.  Pretty cool to see someone be able to figure these out.

[Ken Layton]

How about a picture of this special Hantarex power supply? I've heard about it but never seen one of them myself. A power supply that supplies 135VDC to the monitor? What kind of goofy monitor would be operated that way?

[Level42]

Thanks for the nice comments. I'm an electronics/IT engineer so I should be able to figure these things out, but it's still a challenge sometimes

To Ken, indeed the cab uses a (goofy) Hantarex monitor. Apart from the parts you mention, there's also a hefty resisitor in the "fan area".

The weird thing is that the fan was a 12V unit, and the power connector of the Hantarex is supplying 5V. I'd think 5V is not enough to start the fan. I know 7V will work, cause I have PC fans running on 7V to lower the sound level.
I bought a new fan, but now wan to connect it to 12V and although there's plenty of 12 V around, I need to find a good solution to connect it.

I'll put up a pic of the power supply and monitor ASAP.

I've added two pdf's with information and the schematic of the power supply !

[Nipedley]

Strange, I dont think that you need to use 135v for the monitor though.. I could be wrong, my MTC 9000 has this exact power supply listed in the manual as an "optional" so I guess you can run it from standard as well? Mine's currently running off 120v

ADD: If you're monitor is a 9000, then it can run anything from 115v to 142v according to the manual =)

[Level42]

Haven't identified the model yet. Note that we are talking 135V DC (NOT AC !!!!) here. This voltage is tapped from the transformers' secundary side where it is rectified through a double diode and some elco's.
I guess this process is normaly handled by a simular transformer on a monitor chassis....but you still could be right, although I haven't seen any other connections or stuff.... I will check the monitor details and make a pic as soon as I can spare the time.

[Level42]

Strange, I dont think that you need to use 135v for the monitor though.. I could be wrong, my MTC 9000 has this exact power supply listed in the manual as an "optional" so I guess you can run it from standard as well? Mine's currently running off 120v

ADD: If you're monitor is a 9000, then it can run anything from 115v to 142v according to the manual =)

Well, haven't looked at the monitor itself yet (need to move the cab to do that) but from the monitor identication page by Bob Roberts, it looks a lot like a MTC9000.
It's now running fine as is, so no need to change, but it might be handy in future, thanks for the heads up.

[Robin_l]

[Level42]

Now that's digging up an old thread

I have long since sold my Double Axle......and I kinda regret it....but it did give me the opportunity to buy my beloved Galaxian (for space reasons mainly).

It was fun to get that cab back in great working condition. I hope the new owner is still enjoying it......

[Robin_l]

Yeah, I was digging around for some info, because I've got one which doesn't produce 12V. 

Here's a picture of mine:



The burnt bit is under the transformer.  Fuse FH3 had blown as well.  So far, I've replaced the fuse, and resoldered the joints of the transformer.  I haven't fired it up yet.  I want to get some solvent and clean the soot off first.