Video Problems with 2 Slot? Can anyone help please?

JussFlee · Feb 11, 2006

Hi Lads N' Lasses
Bit of a newbie to these parts but hoping someone can help!
Dug out a consolized 2-slot I made a while back, and having reall issues with display?! The console used to work perfectly (using the same TV as now a Hitachi 28inch CRT). But when I plugged the system in this morning the video has black lines running through it, is very pixelated and looks awful. I have checked all video wiring and fuses etc. but they all seem to be fine? I have attached a few pics hoping someone can help?

I have tried a few carts and all have the same problems!? I have cleaned cart contacts and blown the cart slots on the board but without any luck?
Is this repairable or has the board blown somehow??
Thanks in advance
Juss

Razoola · Feb 11, 2006

Do you get the same problem with both slots? If so the problem is most likely to be a broken trace somewhere.

Raz

JussFlee · Feb 11, 2006

Hi Razoola,
Yes I do get the problem with both slots.
I just thought; I turned the board on with a cart plugged into each slot (I had 2 carts plugged in when I tuned the machine on), I don't really remember testing the console befoee with 2 carts plugged in at the same time, although I did test the both slots with one cart at a time. Could this be the problem? Could i repair the board trace?
Thanks in advance. J

Razoola · Feb 11, 2006

Two games in at the same time should not cause this. You can fix the trace if that is the problem, the hard part is locating which trace is actually broken.

Raz

JussFlee · Feb 11, 2006

How would I go about finding the trace, would I need to use a Multimeter?
or could I post a pic of the board on here for you to take alook at??

Also should I def. assume that it is a broken trace?

Many Thanks
J

Razoola · Feb 11, 2006

JussFlee said:
How would I go about finding the trace, would I need to use a Multimeter?
or could I post a pic of the board on here for you to take alook at??

Also should I def. assume that it is a broken trace?

Many Thanks
J

The type of fault makes it looks like a trace unless the problem happens only while sprites are zooming. Yoll need to look over the board closely with a magnifying glass or something.

Raz

JussFlee · Feb 11, 2006

Ok I'll take a look, will there be a difinate break in the trace?? Where would the most likely break be, what part of the board??
Cheers
J

Razoola · Feb 11, 2006

JussFlee said:
Ok I'll take a look, will there be a difinate break in the trace?? Where would the most likely break be, what part of the board??
Cheers
J

I have no idea, it could be anywhere and hardly visable at all.

Raz

channelmaniac · Feb 11, 2006

If it were me... I'd try to find a pinout of the cart slot and check the various data lines coming from the graphics roms in the cartridges and ground each pin one at a time and fire up the game to see if it made a difference... when you find the pin that doesn't make any difference then you found the dead line.

Trace it back and look for any broken traces. If you find none... start replacing chips that the line goes to. For example if there are any 74LS244 or 245 chips that it goes to... replace it. Those are bus buffer chips that can be turned on/off and maybe one of the inputs or outputs are stuck. You can also look at the data going in/out of the chips if you have a logic probe. Find the pin that has data going in but not coming out.

Pinouts for the various chips can be found online.

RJ

JussFlee · Feb 11, 2006

Thanks man, I just find it strange it was working perfectly. The nwehn I plugged it in again it wasn't!? It's not like it has been anywhere for anything to happen?! Only difference was I put in a cart that I had'nt tried before, but I don't imiagine that could cause they display probs?!
Also been looking for Pinout of 2slot Cart slot but cannot find

I looked at a similar thing by MLK, but couldn;t quite figure out the pinouts

JussFlee · Feb 11, 2006

Using a friendsTv, Running the UnioBios I also checked the Colour Test screen and here are the results:
As you can see the red has a white block 2 blocks in and all colours have a dark black block 2 blocks in?

Razoola · Feb 11, 2006

What version of the Universe Bios is this? From looking at that it seems there could be a RAM error. Go into the Universe Bios main menu (hold down a+b+c on the splash screen) and then into the general settings. Make sure the 'disable bootup hw check' is not checked. If it was checked uncheck it and exit out and then reboot the system and see if a RAM error is reported.

Raz

JussFlee · Feb 11, 2006

thanks Raz, going to try that now, Its an older 2.0 bios

>>Ok tried that I am getting no errors etc. displayed did exactly as you said, tried it a couple of times and reset system 2-3 times. Not recieving any hardware error messages

Razoola · Feb 11, 2006

Im really not sure whats wrong here, I was really expecting an error there. The only other thing I can suggest is giving the main MVS PCB a real good clean and see if that helps. Pehaps there is some gunk somewhere causing a short.

Maybe some of the other techies here know some other things to try.

Raz

JussFlee · Feb 11, 2006

Me too!
I've had a few boards with RAM errors before, this is why it puzzled me.
I seem to have stumped a couple of people as I really cannot find anything worng, and I do not know why it would work one minute then not the next? Oh well, guess I'll keep trying and see if I can get anywhere, thanks for your time Raz! Much appreciated!

JussFlee · Feb 12, 2006

Well just got it back from drying, nothing has changed video still has probs!? Gone over the board with a fine tooth comb and cannot find any broken traces and board is still displaying NO error messages. If any wants to buy the bare board and have a bash let me know!
Cheers

channelmaniac · Feb 12, 2006

PM me with a price that includes shipping...

channelmaniac · Apr 9, 2006

Hmmmm....

Hey Raz...

All the traces seem to be intact...

The Pallette RAM goes to B1 and GO chips (and A12 goes to a 74HC259)...

The VRAM goes to LSPC2-A2 just fine...

Can you give me some insights as to how the Pallette test runs? Which section of RAM does the missing blocks use? I'm wondering if the hardware issue can be tracked down to something simple via the code you have running.

Thanks!

RJ

Code:

Pinouts traced on the NEO-MVH MV2F

Pallette RAM:		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

----------------------------------------
Pallette RAM:		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

-------------------------------------

Video RAM:      62256(7C)
LSPC-40	 1 a14		28 vcc	  vcc
LSPC-37	 2 a12		27 /w	  LSPC-60
LSPC-31	 3 a7		26 a13	  LSPC-38
LSPC-30	 4 a6		25 a8	  LSPC-32
LSPC-29	 5 a5		24 a9	  LSPC-34
LSPC-27	 6 a4		23 a11	  LSPC-36
LSPC-26	 7 a3		22 /oe	  LSPC-59
LSPC-25	 8 a2		21 a10	  LSPC-35
LSPC-24	 9 a1		20 /s	  gnd
LSPC-23	 10 a0		19 d8	  LSPC-48
LSPC-41	 11 d1		18 d7	  LSPC-47
LSPC-42	 12 d2		17 d6	  LSPC-46
LSPC-43	 13 d3		16 d5	  LSPC-45
gnd	 14 gnd		15 d4	  LSPC-44

--------------------------------------
Video RAM:	62256(8C)	
LSPC-40	 1 a14		28 vcc	  vcc
LSPC-37	 2 a12		27 /w	  LSPC-60
LSPC-31	 3 a7		26 a13	  LSPC-38
LSPC-30	 4 a6		25 a8	  LSPC-32
LSPC-29	 5 a5		24 a9	  LSPC-34
LSPC-27	 6 a4		23 a11	  LSPC-36
LSPC-26	 7 a3		22 /oe	  LSPC-59
LSPC-25	 8 a2		21 a10	  LSPC-35
LSPC-24	 9 a1		20 /s	  gnd
LSPC-23	 10 a0		19 d8	  LSPC-58
LSPC-49	 11 d1		18 d7	  LSPC-57
LSPC-51	 12 d2		17 d6	  LSPC-55
LSPC-52	 13 d3		16 d5	  LSPC-54
gnd	 14 gnd		15 d4	  LSPC-53

LSPC = LSPC2-A2
All pins are common between VRAM chips except data pins...

Video Problems with 2 Slot? Can anyone help please?

JussFlee

n00b

Razoola

Divine Hand of the UniBIOS,

JussFlee

n00b

Razoola

Divine Hand of the UniBIOS,

JussFlee

n00b

Razoola

Divine Hand of the UniBIOS,

JussFlee

n00b

Razoola

Divine Hand of the UniBIOS,

channelmaniac

Mr Neo Fix-it

JussFlee

n00b

JussFlee

n00b

Razoola

Divine Hand of the UniBIOS,

JussFlee

n00b

Razoola

Divine Hand of the UniBIOS,

JussFlee

n00b

JussFlee

n00b

channelmaniac

Mr Neo Fix-it

channelmaniac

Mr Neo Fix-it