Galaga Freezes On Startup - Always At 4L

Archived from groups: rec.games.video.arcade.collecting (More info?)

4L is a RAM error. For details see:

http://www.mikesarcade.com/cgi-bin [...] Codes.html

Best,

- Mike -


On 13 Jul 2005 09:15:39 -0700, studiobassist@hotmail.com wrote:
>I have replaced all the rom including the starfield generator and 4L. I
>replaced a couple of the Z80s. So far nothing has helped. The game was
>working and then it just started freezing in the same spot over and
>over.
>
>Any ideas what I can replace or check next?
>
>Thanks,
>Todd

Archived from groups: rec.games.video.arcade.collecting (More info?)

syncbus@gmail.com <syncbus@gmail.com> wrote:
: I've been through the same problems with Galaga boards before,
: sometimes it's just low 5v and sometimes it's a major PIA to track
: down. I don't believe the self test checks each processor so verify
: all those are good, test the 5v on the board too. There are cases of
: some boards being finicky about their working voltages.

Self test only checks the first cpus ability to access its ram/rom, then
hangs in a loop waiting for CPU2 and CPU3 to set some ram values and assumes
they're working if that happens.

--
Mark Spaeth mspaeth@mtl.mit.edu
50 Vassar St., #38.265 mspaeth@mit.edu
Cambridge, MA 02139
(617) 452-2354 http://rgvac.978.org/~mspaeth

Archived from groups: rec.games.video.arcade.collecting (More info?)

I do have correct voltage at the pcb. I didn't know about the mikes
arcade ram error page. I will try replacing 3H to see if it is bad.

Thanks so much for all the input.

Todd

Archived from groups: rec.games.video.arcade.collecting (More info?)

I had a similar problem. Turned out the voltage was just a little too low.
(Partly because I'm using a 40' extension cord and it's plugged ina noutlet
with alot of other things running off the same line)


<studiobassist@hotmail.com> wrote in message
news:1121271339.297326.221370@g49g2000cwa.googlegroups.com...
> I have replaced all the rom including the starfield generator and 4L. I
> replaced a couple of the Z80s. So far nothing has helped. The game was
> working and then it just started freezing in the same spot over and
> over.
>
> Any ideas what I can replace or check next?
>
> Thanks,
> Todd
>