Color ram error

mainman

mainman

CPS2 Person.,
20 Year Member
Joined
Mar 26, 2001
Posts
3,734
Hi guys wondering if you can help me out here. I have a 2 slot with a color ram issue, I replaced both the 5864 color ram chips but the error is still there.

I have noticed however when I power down and back up the READ address will always change. I have followed all the traces and I can not find a broken line anywhere.
 
mainman

mainman

CPS2 Person.,
20 Year Member
Joined
Mar 26, 2001
Posts
3,734
Upon further test I found that the address line changes to, here are the errors I get

00400008 5555 F004

00400000 5555 F000

00400BA2 5555 F000
 
channelmaniac

channelmaniac

Mr Neo Fix-it
15 Year Member
Joined
Nov 29, 2005
Posts
4,275
Yup... Pallette RAMs... the 5864s...

hmmm... Here's the pinouts that I did on a 2 slot board I have here at the house... I'm working on fixing a video problem on it and wanted to make sure all the RAM traces were OK.

If you are getting different messages then it sounds like there's a problem with the RAM. Did you put sockets in for those chips? Also, what did you replace them with?

RJ

Code: 
Pinouts for NEO-MVH MV2F
			4364 (B8)
vcc		1 NC		28 vcc	  vcc
74hc259-12	2 a12		27 /we	  NEO-GO-41
NEO-B1-12	3 a7		26 ce2	  vcc
NEO-B1-11	4 a6		25 a8	  NEO-B1-28
NEO-B1-9        5 a5		24 a9	  NEO-B1-29
NEO-B1-8        6 a4		23 a11	  NEO-B1-32
NEO-B1-3        7 a3		22 /oe	  gnd
NEO-B1-2        8 a2		21 a10	  NEO-B1-31
NEO-B1-159	9 a1		20 /ce1	  gnd
NEO-B1-158	10 a0		19 d8	  NEO-GO-56
NEO-GO-35	11 d1		18 d7	  NEO-GO-55
NEO-GO-36	12 d2		17 d6	  NEO-GO-54
NEO-GO-37	13 d3		16 d5	  NEO-GO-53
gnd		14 gnd		15 d4	  NEO-GO-38

----------------------------------------
			4364 (A8)
vcc		1 NC		28 vcc	  vcc
74hc259-12 	2 a12		27 /we	  NEO-GO-41
NEO-B1-12	3 a7		26 ce2	  vcc
NEO-B1-11	4 a6		25 a8	  NEO-B1-28
NEO-B1-9        5 a5		24 a9	  NEO-B1-29
NEO-B1-8        6 a4		23 a11	  NEO-B1-32
NEO-B1-3        7 a3		22 /oe	  gnd
NEO-B1-2        8 a2		21 a10	  NEO-B1-31
NEO-B1-159	9 a1		20 /ce1	  gnd
NEO-B1-158	10 a0		19 d8	  NEO-GO-23
NEO-GO-62	11 d1		18 d7	  NEO-GO-22
NEO-GO-63	12 d2		17 d6	  NEO-GO-21
NEO-GO-64	13 d3		16 d5	  NEO-GO-20
gnd		14 gnd		15 d4	  NEO-GO-1

NEO-B1 is at E6
NEO-GO is at B7
74HC259 is at E3
 
Last edited:
mainman

mainman

CPS2 Person.,
20 Year Member
Joined
Mar 26, 2001
Posts
3,734
I put sockets in and replaced the chips with some 6264 ram chips. I have used 8 new 6264 ram chips and get the same error
 
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