Need Help with a SEGA Sys. 16 ALTERED BEAST Graphics Problem

Hello everyone,

I need some with a SEGA System 16 ALTERED BEAST graphics problem.

Whenever I power-ON the PCB, the black looks faded and the character sprites are messed-up.

I uploaded pictures of the AB PCB and of the problem at http://s1210.photobucket.com/albums/cc418/Tyranix95/

I also found a AB manual uploaded at http://www.crazykong.com/manuals/

NEO-GEO.com Tech Support seems so smart here that I'm hoping someone knows how to this problem.

Please feel free to post. All ideas welcome. Thanks for your help.

-----Diagnostic History.

0. Won AS-IS, working AB PCB on eBay. Seller says the AB PCB left working. And it shipped via UPS ground. So, perhaps, the caps on my monitor are bad and thus causing the black to fade. And, perhaps, my power supply is bad and under powering the AB PCB.

1. Tested the monitor with my NEO-GEO MVS HARDWARE TEST. All colors--including black--show OK on the monitor, to me.

2. Test the power supply with multimeter at the NEO-GEO MVS JAMMA edge connector. Meter shows all Ground Leads at 0 V DC; All +5 V DC Leads at +4.99 to +5.00 V DC; and all +12 V DC Leads at +12.09 to 12.10 V DC.

3. Test the power supply with multimeter at the AB PCB edge connector. Meter shows all Ground Leads at 0 V DC; All +5 V DC Leads at +4.99 to +5.00 V DC; and all +12 V DC Leads at +12.09 to +12.10 V DC.

4. Ran the AB PCB MEMORY TEST. All ROM and RAM chips test OK.

5. Reseated the AB PCB "B" board.

No change: Graphics problem shill persists.

EVERY single one of those scratched traces on the bottom of the board need to be checked for continuity. You probably have a trace that is broken because of the scratches.

Jumper them with some 30 gauge kynar wire wrap wire.

http://www.radioshack.com/product/index.jsp?productId=2062640

RJ

This looks like bad RAM to me, probably the SRAMs at F2, F3, F4 or F5 (note these might be called G2, G3 etc. Probably just one of the 4 has died.

The built in diagnosis sometimes does not include all RAM chips and it varies from game to game so your in-built diag may not have even tested these. Re run the tests and post a screenshot of the output.

Note the above locations are for a System16B board, the one with the smaller ROM board, not the dual huge boards on a 16A board set.

RJ,

Thank you.

I'll stop by the shack tomorrow. Get some 30 gauge kynar wire wrap wire. And, start checking those scratched traces on the bottom of the board for a broken trace.

I'll post back when I have more info.

And, Thanks, Again.

Tyranix95

Whoever that seller is, he's a liar.

Did the auction state that it was in working condition? If it did it is the sellers obligation to make sure you receive a working board. I doubt shipping it ground made it screwed up and scratched like that.

As for the graphics problem the rom board A14-16 and B1-8 handle the graphics.

Did you try popping out each of those chips individually and putting them back in?

Hello everyone,

Thanks for all your help.

I have new information.

Seller responded with refund offer, and I've accepted it.

Posted final entry to to Diagnostic History.

Unfortunately for this AB PCB, the graphics problem shill persists.

And, Thanks, Again, For All Your Help.

You were all way

Diagnostic History (Final Update.)-----

6. Began testing the bottom of the AB PCB with my multimeter's line trace function at SEGA connector and at scratched areas. Tested PCB traces "BEEP" good. Good traces marked red in new pic (that I will upload in a bit). But, more PCB traces to check.

7. I found the F/G 1-5 RAMs on the AB PCB. Ran the AB MEMORY TEST MENU, again: No change from previous pics (see above). F/G RAMs not on the AB TEST MENU. Never tested RAMs without a test menu before. Do I line trace these RAM chips?

MEMORY TEST MENU.
1.-----ROM TEST: A5 Good; A7 Good.
2.-----SCRATCH RAM: E9 Good; E10 Good.
3.-----SCROLL VIDEO RAM: H13 Good; J13 Good.
4.-----FIX VIDEO RAM: H15 Good; H16 Good.
5.-----COLOR RAM: J9 Good; J10 Good.

n1. Sec. edited, once, for clarity.

8. Reseated ROM chips A14-16 and B1-8 on the "B" board. No change: Graphics problem shill persists.

9. Received sellers refund offer, and accepted it.

----END.