Virtua Racing: Advice?

[Nick White]

I have a stand-up unit of Sega Virtua Racing with the accelerator, gas pedel
and force feedback steering wheel.

All the graphics look good until you start a race, and the road and car are
missing. I can see most of the background and the sky, but the important
things aren't showing up.

Any ideas what might be wrong, and how I could fix it?

Thanks,
Nick

[Steve Muccione]

I believe that board has a dedicated 3d graphics co-processor... sounds like
all you're getting is 2d background images.

I'd suspect the 3d co-processor path... bad coprocessor, rom/ram or
something in the co-processor path.

I don't know much about the board, sorry.

steve.

"Nick White" <nn...@spacemky.com> wrote in message
news:ZvRwb.286$3S5...@newssvr27.news.prodigy.com...

[Nick White]

That sounds exactly like what is going on. How can I locate the 3d co
processor, and see if anything has come loose? The machine was bought at an
auction, and it worked before it was bought. We think that a guy tampered
with the machine, in an effort to make money off the repair... Is it
possible for him to have done something to turn off the 3d?

Thanks,
nw

"Steve Muccione" <home*DOT*mucc...@verizon.net> wrote in message
news:9dYwb.5480$nP3....@nwrdny03.gnilink.net...

[Steve Muccione]

Unfortunatly I don't know exactly... there's probably any number of things
he could do to cause issues in the 3d pipeline... It could be as simply as
replacing a rom with a blank one... or he could have unsoldered a
resistor... it'd be really hard to trace unless you had the full schematics.

Is there any self test capability? Does it pass everything?

steve.

"Nick White" <nn...@spacemky.com> wrote in message

news:A14xb.448$wx4...@newssvr27.news.prodigy.com...

[Shatter Proof]

I've had it where the self tests all test out fine, but the 3d still drops.
I've also had good luck with taking the stack apart and cleaning the boards
off, mostly just getting rid of the dust!

Brian Emmel

"Steve Muccione" <home*DOT*mucc...@verizon.net> wrote in message

news:9u4xb.39$UG2...@nwrdny03.gnilink.net...

[Nick White]

Yeah, the self tests all run good, and the cabinet looks really clean
inside. There is a metal box inside there which I haven't opened up yet...

You mentioned taking the stack apart. What exactly is the stack?

"Shatter Proof" <shatte...@sbcglobal.net> wrote in message
news:vs9m6va...@corp.supernews.com...

[Mark (UK)]

Hiya!

Repeat after me......

MY 315-5422 IS DEAD

:-)

95% of these faults are caused by one chip, a 315-5422 going bad on the
Video board (lower of the large 2). Unfortunately:
1. It's an SMT, so is only replaceable if you've got the right gear
2. Is no longer made by Sega*
....so even if you did have the right tools, you can't get a replacement.

The answer is to get a working video board from a Virtua Fighter and
change it over. VF boards do come up on eBay, but you've got to take the
risk of if that works. The video boards are interchangeable between all
model 1 games, the CPU boards are not, they are locked to a particular
game (Except Wing War and Star Wars Arcade).

If you get stuck, I've got working video boards here, but I'm in the UK,
so postage will be a bit heavier, if you can't get one stateside.
(Presuming you are stateside?)

Good luck! Yours, Mark.

*The 315-5422 is actually made by Fujitsu from a Sega design. The
315-5422A is made by Toshiba, and is a much more reliable component,
although they still do fail occasionally. I'll bet a ham sandwich that
your's is not the A variant!

[Patrick Griffith]

"Nick White" <nn...@spacemky.com> wrote in message
news:ZvRwb.286$3S5...@newssvr27.news.prodigy.com...

You probably have a bad video board or CPU board. If you open the metal
cage inside the cabinet you will see a stack of four PCBs (ROM, CPU, video &
comm). The CPU board has a string of red and green LEDs along the edge.
These LEDs are a better indicator of whether or not the boards are operating
properly than the self test. Four of the green LEDs should flicker rapidly
as the graphics coprocessors on the CPU board render polygons. If any of
the green LEDs go out, or you see any of the red LEDs light up (besides the
power LED, which is always on), then there is something wrong with the
graphics coprocessors. Usually the problem is related to lifted pins on the
chips closest to the edge of the board. After many power and temperature
cycles the pins become desoldered and make an intermittent connection. I
had this problem with my own Virtua Racing PCB stack. Try flexing the
corners of the board slightly while the game is on. If the polygons
reappear then that is your problem. You will have to use a magnifying glass
to see which pins are lifted and solder them back down. Unfortunately, this
is not a simple task.

If the green LEDs are all flickering and you still lose polygons, then the
problem is likely related to the video board rather than the CPU board.
This may be impossible to fix unless you have a lot of experience. It would
probably be easier to find another video board. You can swap out a video
board from another Sega Model 1 game like Virtua Fighter, but you cannot
swap out the CPU board with anything but another Virtua Racing CPU board.

Patrick