19XX CPS2 Graphics Fault

[idc]

Hi guys,

Anyone able to offer me some pointers as to what I can do to rectify this?





I've ruled out the motherboard (this one works with other games, and I get the same fault with another motherboard on this game). Also verified the mask ROMs by checking their readouts with MAME -romident, even tried EPROM substitutes for the mask ROMs and still the same problem.

Anyone seen anything similar before who can advise where I should be looking in order to fix this mess?

[richy13]

hello ian

Have you tried swaping the PALs i mean all 3?or if 2 of them are soldered just PAL (3)

richard

[idc]

PAL 1 and 2 are soldered, but I did try swapping PAL 3 previously and again I got the same.

I think it's completely dead now anyway. Just tried it again get a dark red screen. It was already running phoenix ROMs, so it's not that. Don't even get audio with the suicide tester in socket 03, just the same red screen. Heh.

[porchio]

have you checked the pins on the cart connectors?
i bought a board a while back that just red screened and there were several bent pins, also put a bit of pressure on the boards to make certain your getting a decent connection.
i know its simple stuff but at least your ruling it all out first

[PrincessPrinPrin]

Since it's on the romboard and it affects sprites, I say bad object ram. It's a couple of SMD 64K located at 3A and 4A.

[idc]

have you checked the pins on the cart connectors?
i bought a board a while back that just red screened and there were several bent pins, also put a bit of pressure on the boards to make certain your getting a decent connection.
i know its simple stuff but at least your ruling it all out first

One of the first things I checked, so already ruled out. I'm actually running the board out of the case, and it's definitely pushed on firmly and fully. Pins are all intact, and other games are running fine on the motherboard.

Since it's on the romboard and it affects sprites, I say bad object ram. It's a couple of SMD 64K located at 3A and 4A.

Worth looking at, if I can get it back to a bootable state, I suppose!

Thanks to you both for your suggestions.

[idc]

Right, I've pinpointed the fault to a dodgy LS245. I've currently got some replacements on order, hopefully I can desolder the old one and solder in the new one without too much fuss (also ordered some kynar wire just in case).

[channelmaniac]

Right, I've pinpointed the fault to a dodgy LS245. I've currently got some replacements on order, hopefully I can desolder the old one and solder in the new one without too much fuss (also ordered some kynar wire just in case).

Bridge the pins with solder to give them extra staying power and keep from lifting pads... then use some tiny snips to snip the pins at the body of the chip. With the chip body gone it's easy to get rid of the remaining pins/solder and keep from lifting pads.

Or, you could do it like I do and use a PACE solder station with a ThermoTweeze iron to lift the chip right off.

[idc]

Right, I've pinpointed the fault to a dodgy LS245. I've currently got some replacements on order, hopefully I can desolder the old one and solder in the new one without too much fuss (also ordered some kynar wire just in case).

Bridge the pins with solder to give them extra staying power and keep from lifting pads... then use some tiny snips to snip the pins at the body of the chip. With the chip body gone it's easy to get rid of the remaining pins/solder and keep from lifting pads.

Or, you could do it like I do and use a PACE solder station with a ThermoTweeze iron to lift the chip right off.

Hehe, I'd love a PRC-2000 or similar, but it's a little cost prohibitive and possibly overkill for me right now.

Cheers for the tip. I'll this thread updated during the repair.