Built a supergun, doesn't work.

[ChurchOfSolipsism]

So I finally finish the soldering, connect the supergun to the TV (it's a German one so I have it connected via Scart), connect an old Tetris PCB I got for testing, switch the supergun on, then get some kind of reaction (similar to when you switch on a console, just a couple of white stripes on the screen for a short moment), then the screen goes to black and nothing happens.

I have done the following things:
- checked if the wires have all been correctly connected and properly soldered (all fine)
- checked the voltages supplied by the power adapter again, they're fine
- checked if there are any electrical shortages, couldn't find any

I can't guarantee that the Tetris PCB works; I do have an NG mobo that I know works but I'm kinda afraid of using it for testing...

any suggestions?

edit: I used this guy's tutorial (all in German, I'm afraid):

http://www.systemshock.info/supergun-bauanleitung.htm"

[ChurchOfSolipsism]

Right, just tried it with the NG mobo with the same results.

I'd be really grateful for any pointers here...

[ninn]

Can you check the voltage on a rom chip? Do you know how to do it? Use your multimeter and look up the pinout of the chip you want to measure to find power/ground. If it is powered, you can rule the power-part of the supergun out.

[ninn]

.. and, btw: the power-part of that supergun is a bit "minimalistic":

that supergun delivers just power to 2 pins: 3 and 6.

Jamma asks for power on 3,4, C and D and 6 and F.


Ground is just on one pin too, where as jamma asks for ground on at least 6 pins... i guess even more.

compare to this picture (random picture from the net):

[ninn]

a picture of your solder-work may help too!

[yosai]

I'd also try another TV if you have one.

[ChurchOfSolipsism]

.. and, btw: the power-part of that supergun is a bit "minimalistic":

that supergun delivers just power to 2 pins: 3 and 6.

Jamma asks for power on 3,4, C and D and 6 and F.


Ground is just on one pin too, where as jamma asks for ground on at least 6 pins... i guess even more.

compare to this picture (random picture from the net):

Thnks. I guessed that guy must know what he's talking about since he had done many superguns before which all worked. I guess I will solder more wires so that all the "power pins" are connected.

Can you check the voltage on a rom chip? Do you know how to do it? Use your multimeter and look up the pinout of the chip you want to measure to find power/ground. If it is powered, you can rule the power-part of the supergun out.

Sorry, but since I'm a noob I don't even know how to identify a/ the rom chip... even if I find it, if the PCB is damaged, won't the voltage read zero since no current is flowing?

a picture of your solder-work may help too!

I apologize for not having a camera. I can promise you though that my solder-work is top-notch..

I'd also try another TV if you have one.

Good idea, unfortunately the only other TV I have available doesn't accept NTSC signals since it's an old piece of ****.

[yosai]

You've go an NTSC encoder in there too? Surely the native RGB would be better.

[ChurchOfSolipsism]

You've go an NTSC encoder in there too? Surely the native RGB would be better.

Ooops, no I don't have an NTSC encoder in there. Somehow I was convinced that a supergun produces an NTSC signal.

Anyway, used my laptops camera to take some bad pics:
http://i110.photobucket.com/albums/n105 ... nsides.jpg"
http://i110.photobucket.com/albums/n105 ... 192819.jpg"
http://i110.photobucket.com/albums/n105 ... 192838.jpg"
http://i110.photobucket.com/albums/n105 ... 192828.jpg"
Not that it's gonna help I guess.... too much chaos.

[ninn]

... no ntsc in there, just plain jamma rgb wired to the scart jack. I don't think that is good for the tv.

Would be far stretched to call that thing a supergun.
I'd rather call it white wires in a black box.

[ninn]

okok, your (power) wires look very thin.

get a multimeter and measure voltages on the board. you have to do this to if you want to know if the board is running or not.

You have a multimeter, right?

[ChurchOfSolipsism]

OK, will do & report back. Thanks guys for all the advice!

...

Good, so the Tetris PCB is getting 4.8 and 12.2 volts (measured at the piece of PCB which connects to the Jamma harness - that's where I'm supposed to measure voltage, right?)

PS: the wires used for power are the thick (not the thin) black ones, so I'm assuming they don't have too much resistance?

[ChurchOfSolipsism]

Interesting new development: apparently, when I switch on the supergun, I get to the PCB's test menu (haven't found a way to leave it yet; pressing the service or test buttons or any combination of P1/2 start and Coin 1/2 does nothing, and the PCB doesn't have any dip switches). Thing is, picture is almost black, I can barely make out the dark grey letters, which is why during the day I couldn't see anything, so I had to assume it didn't work.

Is this an interesting new clue or does it mean that I have **** up and can start over again?

[KmanSweden]

I didn't see any resistors on the RGB to Scart leads..
Here's what I'm on about, in Swedish but I guess you can figure it out..

4 x 150 ohm
1 x 10 Kohm
1 x 1 Kohm
1 x 280 ohm

Also.. note att the GND's and Video GND's..

[ChurchOfSolipsism]

Had the bright idea of checking the SCART cable (which I've had for at least 20 years)... turns out only three of its 21 pins actually have a connection. Stupid broken piece of ****. Ordered a new cable which should arrive tomorrow; will post results again. Thanks for hanging in fellas.

I didn't see any resistors on the RGB to Scart leads..
Here's what I'm on about, in Swedish but I guess you can figure it out..

4 x 150 ohm
1 x 10 Kohm
1 x 1 Kohm
1 x 280 ohm

This might be an extremely stupid question, but are you sure I really need to solder those resistors in? I've read several different supergun tutorials and none of them say anything about any resistors....

Also.. note att the GND's and Video GND's..

Sorry man, but what is that supposed to mean?

[KmanSweden]

This might be an extremely stupid question, but are you sure I really need to solder those resistors in? I've read several different supergun tutorials and none of them say anything about any resistors....

The signals are way too powerful for a TV. That's why you need RGB amps when your running Console2jamma's.
You might end up destroying you TV.

Sorry man, but what is that supposed to mean?

I thought this was your image (my bad..) and there just seemed to be missing wires to the Scart...

[ChurchOfSolipsism]

HAPPY ENDING

Right, for those that care, I got everything to run. Turns out a new Scart cable was what I needed since the old one was ****, no additional soldering was required, power was sufficient. It runs an NG single slot, a PGM mobo and a Gladiator/ Road off the Sword pcb flawlessly (including sound), but the Tetris PCB I got for testing gives me terrible picture quality and the sound consists largely of noise while the music plays very quietly in the background. I should probably put it in the for free thread.

Anyway, the potentiometers I ordered arrived today, I'll put those in as well to make sure the TV won't get RGB signals that are too strong.

Now, let's order some black acrylic glass for that high end/ sure to turn out **** supergun I was planning to build...

[Asure]

I built several superguns over time, some were made of just scrap wires and crappy cables, some were pretty elaborate wood-mounted and all. I learned a lot from it
So, now you have already learned a lot by building your first one on your own, but it would never look as nice as a pre-built factory fresh one on a single pcb.

You could order one from Smallcab.net. The light version is only 28 euro, and a nice case comes at 15 euro. I have one of these for my test bench, it's pretty good!

[ChurchOfSolipsism]

I built several superguns over time, some were made of just scrap wires and crappy cables, some were pretty elaborate wood-mounted and all. I learned a lot from it
So, now you have already learned a lot by building your first one on your own, but it would never look as nice as a pre-built factory fresh one on a single pcb.

You could order one from Smallcab.net. The light version is only 28 euro, and a nice case comes at 15 euro. I have one of these for my test bench, it's pretty good!

I guess they're looking pretty swell if they look anything like Bencao's supergun PCBs (which he also sells sandwiched between two plexiglass plates). However I'm planning a full enclosure made of plexi plus the accompanying stick in the same design. Something very roughly along the lines of this, only with knobs and **** on the front: