I'm having problems on trying to display a Sky Smasher PCB through my supergun(direct RGB) on my TV.
If I'm not mistaken it's the same board as Blood Bros, maws lists it at 59.390000Hz. Should be working on a bog standard, NTSC capable, PAL TV no?
Any ideas?
EDIT: tried two different TV sets and still no sync...
EDIT2: seems like sync is not/not the only problem, now I don't get any sound either.looks like this board is dying... nice.
Sky Smasher hardware problem
Sky Smasher hardware problem
Last edited by ZOM on Thu Jun 17, 2010 11:21 pm, edited 1 time in total.
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Re: Sky Smasher hardware problem
OK, seems like I was trying this whole troubleshooting business the wrong way around - has nothing to do with the game not syncing after all,
So I started to look at the PCB for a while - everything looks clean.
Next step, remove all roms - result: picture! plugged them one after another in, black screen, yay.
After several minutes of checking ICs I got closer to the culprit, situation looks like this now: If I remove roms 1,2,3 and 4 the game runs. I believe those are two sound roms and the other two used for text. don't quote me on that tho.
If I put in rom 4 the game still runs and also shows part of the text, but soon after there's a small chance that it goes all black again.
Now, assuming it shows picture with rom 4, If I plug rom 3 in I get the other text overlay. Good.
Next - as soon as I try it with either rom 1 or 2 I get a black screen. And this is where it ends... no matter what I try, I can't plug the last(first) 2 roms in or the board won't run.
again, any ideas?
So I started to look at the PCB for a while - everything looks clean.
Next step, remove all roms - result: picture! plugged them one after another in, black screen, yay.
After several minutes of checking ICs I got closer to the culprit, situation looks like this now: If I remove roms 1,2,3 and 4 the game runs. I believe those are two sound roms and the other two used for text. don't quote me on that tho.
If I put in rom 4 the game still runs and also shows part of the text, but soon after there's a small chance that it goes all black again.
Now, assuming it shows picture with rom 4, If I plug rom 3 in I get the other text overlay. Good.
Next - as soon as I try it with either rom 1 or 2 I get a black screen. And this is where it ends... no matter what I try, I can't plug the last(first) 2 roms in or the board won't run.
again, any ideas?
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Re: Sky Smasher hardware problem
Its likely that those two roms are faulty, roms usually share the data bus and address bus, so all ROMs are being addressed at all times, however the PCB controls which ROM gets to talk on the data bus as it is essential that the bus is only driven by one chip. If more than one tries to talk the highs from one chip cancel out the lows from the other and you get rubbish instead of data. Its possible that these roms have lost the ability to shut up, ie their OE pins are being ignored.
Its also possible that the PCB is faulty and always has these two ROMs output enabled (OE). With the vast majority of ROMs the OE pin allows the chip to talk when it is logic low, and stops it putting anything on its data pins when OE is high.
Get a logic probe on the OE pins in the empty sockets, you should see activity, ie high low transitionss
Its also possible that the PCB is faulty and always has these two ROMs output enabled (OE). With the vast majority of ROMs the OE pin allows the chip to talk when it is logic low, and stops it putting anything on its data pins when OE is high.
Get a logic probe on the OE pins in the empty sockets, you should see activity, ie high low transitionss
Re: Sky Smasher hardware problem
Fixed the picture! The connections on ROM 2's socket were dodgy, so I resoldered it and now it works fine. heh.
Now I just need to find out why I don't get sound. Well, I *do* get sound but you can barely hear it and the pot on the board's amp doesn't seem to work. *scratcheshead*
Seibu boards seem to like me...
Anyways, Thanks for the help!
Now I just need to find out why I don't get sound. Well, I *do* get sound but you can barely hear it and the pot on the board's amp doesn't seem to work. *scratcheshead*
Seibu boards seem to like me...
Anyways, Thanks for the help!
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