Need help for Hammerin' Harry M84-A with graphic glitches

[vsl]

I trying to fix Hammerin' Harry M84-A-C with Graphic glitches.
Test give bad ram NG 9 .
Where is location this chip.
Thank you

 

[TheDaddy]

Board pictures may help.

Dave.

 

[vsl]

Someone did a handyman before the board came to me and fixed the problem very quickly with a X on one chip.

 

[Georgian2]

I have an bootleg wich gives an error like this if the voltage is too low. Maybe it helps.

 

[vsl]

I have an bootleg wich gives an error like this if the voltage is too low. Maybe it helps.

 

[vsl]

Voltage is corect 5.00 in jamma,at the far end of pcb is 4.93

 

[Funhouse71]

Hammy mentions on the arcade projects forums that NG 10 relates to one of the 4 x 2018 rams on the top board for M84 hardware so this would mean its possibly one of these rams below.

https://www.arcade-projects.com/threads/irem-pcb-dragon-breed-m72-no-sprites-ram-ng-rom-ok.11188/

I'm not sure if IC11= NG7, IC12 = NG8, IC13 = NG9 and IC14=NG10 or vice versa so perhaps check out rams at IC12 and 13.

 

[TheDaddy]

Just gonna post same as Funhouse - Has to be these rams 6116.

Dave.

 

[vsl]

i check these IC11, IC12, IC13, IC14 on all 4 chips the address bus is stuck to low and tracked her down to this skinned custom chip 64pin.

 

[Ace`]

Did you lift the pin at the custom to make sure it's not one of the rams pulling it low? It most likely is the custom though I've seen a few bad GA22 customs already.

 

[vsl]

I will remove all 4 rams and see .

 

[vsl]

Тhe case is solved...
unfortunately it turned out to be true that the custom chip is damaged.
After removing rams and testing them, they all work.
I removed and customized the chip ... after elementary measurements between legs his no gave resistance anywhere .
Can such a chip (i think is Nanao KNA70H015(11) ) be found anywhere?
Thank you !

 

[TheDaddy]

caius's Content - Aussie Arcade

www.aussiearcade.com

Dave.

P.S He is on here I think , The guy is a genius ! No clue where you buy them from though ?

 

[Funhouse71]

This is Caius's Ebay Shop maybe contact him there

https://www.ebay.com/usr/namcosystem1

He has done a repro of this chip see here for details:-
https://caiusarcade.blogspot.com/2021/05/irem-kna70h01511-and-kna70h01612.html