gyruss pcb repair
- Thread starter leslie
- Start date
I always take a look at the MAME source to find out information like this its all available online with a quick google search. For Gyruss https://github.com/mamedev/mame/blob/master/src/mame/drivers/gyruss.cpp Line 578 is the start of all the ROM info.
Specific to the Graphics ROM's are:
smarty2018-03-28 20:08:14
Specific to the Graphics ROM's are:
Code:
ROM_REGION( 0x8000, "gfx1", 0 )
ROM_LOAD( "gyrussk.6", 0x0000, 0x2000, CRC(c949db10) SHA1(fcb8bcbd2bdd751fecb322a33c8a92fb6f07a7ab) )
ROM_LOAD( "gyrussk.5", 0x2000, 0x2000, CRC(4f22411a) SHA1(763bcd039f8c1838a0d7da7d4dadc14a26e25596) )
ROM_LOAD( "gyrussk.8", 0x4000, 0x2000, CRC(47cd1fbc) SHA1(8203c4ff0b1cd7b4dbc708e300bfeac1e7366e09) )
ROM_LOAD( "gyrussk.7", 0x6000, 0x2000, CRC(8e8d388c) SHA1(8f2928d71c02aba977d67575d6e34d69bda2b9d4) )
ROM_REGION( 0x2000, "gfx2", 0 )
ROM_LOAD( "gyrussk.4", 0x0000, 0x2000, CRC(27d8329b) SHA1(564ff945465a23d93a93137ad277298770dfa06a) )smarty2018-03-28 20:08:14
Thumbs up to smarty, i'm a bit more low-tech and read the schematics.
I spoke on the phone with Leslie on either Monday or Tuesday (days are a blur), its either a bad ROM or signalling to that ROM.
Post some pictures of the screen you're getting, lets see if we can get you to sort this one yourself.
If you do get totally stuck like I said on the phone, i'll add it to your pile of stuff i'm working on for you.
I spoke on the phone with Leslie on either Monday or Tuesday (days are a blur), its either a bad ROM or signalling to that ROM.
Post some pictures of the screen you're getting, lets see if we can get you to sort this one yourself.
If you do get totally stuck like I said on the phone, i'll add it to your pile of stuff i'm working on for you.
Schematics are great if they're available and you understand what you're looking at, a few years back I didn't have a clue, you've just got to get stuck in and start learning.
Let see some photos of the fault.
Do you have a Eprom reader, logic probe or O'scope to assist with the repair?
Let see some photos of the fault.
Do you have a Eprom reader, logic probe or O'scope to assist with the repair?
First I’d pull out the socketed chips and clean the legs with a fibreglass pencil, the customs especially seem prone to tarnished legs and this could cause this fault.
Second there’s a very handy test rom available that goes in the empty socket on the board, that should identify bad ram.
Second there’s a very handy test rom available that goes in the empty socket on the board, that should identify bad ram.
The test rom is on Porchy's site: http://www.jammarcade.net/gyruss-test-rom/
smarty2018-03-31 10:51:22
smarty2018-03-31 10:51:22
NivagSwerdna
Active member
Looks like the sprites repeat 4 times. Either an addressing A2 on gfx ROM (easy) (or ROM itself) or demuxing when displaying sprites (hard)?
PS
Gyruss architecture seems to have designed by a mad person... will have to get myself a Gyruss board to play with.
PS
Gyruss architecture seems to have designed by a mad person... will have to get myself a Gyruss board to play with.
shoestring
Newbie
- Credits
- 159CR
Test rom binary is free. If you don't have the tools then contact someone with a device programmer to give you a hand.
I'm sure someone near you can help.
shoestring2018-04-01 13:09:16
I'm sure someone near you can help.
shoestring2018-04-01 13:09:16
shoestring
Newbie
- Credits
- 159CR
You can always try Hobby Roms in Canada, I think he charges $15 per chip.
GadgetFreak
Active member
PM me your address, I'll burn one for you and send it.
I have a bootleg Gyruss which has similar issues but haven't had the chance to narrow down the problem yet. I can't run the test rom on it as it doesn't have the socket. Not sure if the test rom will help you much but it's worth a go.
I have a bootleg Gyruss which has similar issues but haven't had the chance to narrow down the problem yet. I can't run the test rom on it as it doesn't have the socket. Not sure if the test rom will help you much but it's worth a go.
shoestring
Newbie
- Credits
- 159CR
I thought that might be the case.
Since you've already swapped out all the socketed chips then that narrows the problem down to something else.
Can you boot into diagnostic mode, enter the sprite browser and take some screenshots.
To do this flip dip2 of DSW3 or you can simply hold down 2p start whilst powering the game on.
Since you've already swapped out all the socketed chips then that narrows the problem down to something else.
Can you boot into diagnostic mode, enter the sprite browser and take some screenshots.
To do this flip dip2 of DSW3 or you can simply hold down 2p start whilst powering the game on.