Twin Cobra issues

jessiewonka · Post by **jessiewonka** » Sat Apr 11, 2015 8:45 pm

I picked up a Twin Cobra pcb which boots, plays, has sound, but the image is very faint and flickery and kinda jacked.

After prodding around for an hour I've got zero ideas so far.

jepjepjep · Post by **jepjepjep** » Sat Apr 11, 2015 9:04 pm

That looks like a bootleg pcb.

jessiewonka · Post by **jessiewonka** » Sat Apr 11, 2015 9:12 pm

Yeah I think so too. And likely not worth the $88 I paid on YJA.

Post by **Dave_K.** » Sat Apr 11, 2015 9:49 pm

I have a bootleg Gemini Wing that looks the same, but when I hook it up to a supergun it looks fine. If you have more than one cab (or friends with cabs) try it out on a few as some monitors may sync fine while others will look like those pics.

jessiewonka · Post by **jessiewonka** » Sat Apr 11, 2015 10:14 pm

Dave_K. wrote:I have a bootleg Gemini Wing that looks the same, but when I hook it up to a supergun it looks fine. If you have more than one cab (or friends with cabs) try it out on a few as some monitors may sync fine while others will look like those pics.

Ah interesting, ok.

emphatic · Post by **emphatic** » Sat Apr 11, 2015 10:32 pm

You could try soldering a wire from the GND to the VIDEO GND and see if it helps. Or just sandwiching a wire between the edge connector on the PCB and your JAMMA harness. Just be careful so the GND side of the wire doesn't touch the power pins on the harness.

Post by **system11** » Sat Apr 11, 2015 11:18 pm

emphatic wrote:You could try soldering a wire from the GND to the VIDEO GND and see if it helps. Or just sandwiching a wire between the edge connector on the PCB and your JAMMA harness. Just be careful so the GND side of the wire doesn't touch the power pins on the harness.

This, I had one of those bootlegs and it doesn't have a video ground. Dreate a wire link from 14 to the ground plane similar to what someone did on mine:

jessiewonka · Post by **jessiewonka** » Sat Apr 11, 2015 11:59 pm

Indeed that worked, thank you!

It uncovered a new problem. Player one stick only moves you up and right, same for a couple of the buttons. Player two anything throws a "tilt" message and reset the game.

Post by **system11** » Sun Apr 12, 2015 12:25 am

Check your +5v, it's a greedy board. Failing that it'll probably be a fucked up LS240 dealing with controls.

jessiewonka · Post by **jessiewonka** » Sun Apr 12, 2015 12:39 am

Fixed for the most part, my fault. The wire I used is heavy gauge and kept the jamma connector from seating all the way. I really need to get a variety of wires to pull from, only had a piece of 12g!

After this though it turned green, reseated, went back to goofy controls, reseated, and now it's fine and dandy, other than it still has a slight audio buzz (before and after this fix).

Good to know on the LS240, thx for all the help guys.

emphatic · Post by **emphatic** » Sun Apr 12, 2015 12:01 pm

Cool.

Post by **Dave_K.** » Sun Apr 12, 2015 4:32 pm

Nice, I'll have to try this with my board.

jessiewonka · Post by **jessiewonka** » Sun Apr 12, 2015 5:15 pm

emphatic wrote:Cool.

I just realized who you are -- love your site man! Take it back up take it back up...

emphatic · Post by **emphatic** » Sun Apr 12, 2015 6:51 pm

jessiewonka wrote:Take it back up take it back up...

It's not down, I just don't have any free time right now.

jessiewonka · Post by **jessiewonka** » Mon Apr 13, 2015 1:30 am

emphatic wrote:
jessiewonka wrote:Take it back up take it back up...
It's not down, I just don't have any free time right now.

I meant as in pick it back up. Miss your updates!

shmups.system11.org

Twin Cobra issues

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