Neo Geo 4 slot help!

Beaps

Beaps

Kabuki Klasher
Joined
Oct 8, 2008
Posts
124
Hi All

I got a Neo Geo 4 slot that's stuck in the test menu no matter what the dip switches are set to.

Any ideas where to start in my attempt to fix it?

Any help appreciated
B
 
Beaps

Beaps

Kabuki Klasher
Joined
Oct 8, 2008
Posts
124
I have had a look mate & it looks pretty minty. I noticed it still has the original battery on so I will fish that off and see if that has done any damage.
 
everten

everten

Edo Express Delivery Guy
10 Year Member
Joined
Sep 2, 2012
Posts
348
Sounds like the board isn't seeing a game. Have you tested the cart in another board or have a known working game to test?
 
Beaps

Beaps

Kabuki Klasher
Joined
Oct 8, 2008
Posts
124
Yer I have tested the mvs games I got and they are all workers.
 
everten

everten

Edo Express Delivery Guy
10 Year Member
Joined
Sep 2, 2012
Posts
348
It doesn't think a cart is inserted. Check if the battery leaked. It may have damaged traces on the board. You can also try reseating the top and bottom boards together if battery looks ok.
 
Beaps

Beaps

Kabuki Klasher
Joined
Oct 8, 2008
Posts
124
OK so I removed the battery but it looked pretty mint, and thought I could see a bad trace but it was OK. I have also checked all the traces around the battery and they checkout fine.

 
Last edited:
everten

everten

Edo Express Delivery Guy
10 Year Member
Joined
Sep 2, 2012
Posts
348
Pics of the battery area on both sides of the board might help.
 
ne7

ne7

Armored Scrum Object
15 Year Member
Joined
Aug 12, 2008
Posts
268
It's prob dirty slots m8 if its that minty :) Try cleaning the first slot out with isopropyl on a bit of cloth wrapped round a cut up dvd case cut to size - good bit o' scrubbage might well get it booting...
 
ne7

ne7

Armored Scrum Object
15 Year Member
Joined
Aug 12, 2008
Posts
268
make sure it's 100% dried out before turning back on tho :D
 
Beaps

Beaps

Kabuki Klasher
Joined
Oct 8, 2008
Posts
124
Just cleaned out slot 1, plugged it back in and....... Still the same lol
 
bartre

bartre

Haomaru's Blade Shiner
10 Year Member
Joined
Oct 27, 2009
Posts
681


definitely a battery leak, i've circled the apparent damage, though there's probably more.
 
HeavyMachineGoob

HeavyMachineGoob

My poontang misses Lenn Yang's wang
10 Year Member
Joined
Apr 3, 2011
Posts
5,849
You should grab a JAMMA pinout, find the test screen pin and check it with a multimeter, it's probably grounding out somewhere.
 
bartre

bartre

Haomaru's Blade Shiner
10 Year Member
Joined
Oct 27, 2009
Posts
681
how did you test them?
it's possible that there is a loss across those lines, but them to still test good with a continuity tester.
 
ne7

ne7

Armored Scrum Object
15 Year Member
Joined
Aug 12, 2008
Posts
268
oh did not see that pic /o\

could be those exposed traces are bridging w. each other too (might still beep thru too if so) give em a good wipe down and clean any of the other bits off the board
 
Beaps

Beaps

Kabuki Klasher
Joined
Oct 8, 2008
Posts
124
I checked the continuity from point A to point B they was all fine. No bridging
 
Beaps

Beaps

Kabuki Klasher
Joined
Oct 8, 2008
Posts
124
OK I checked all the traces around the battery and they checkout fine with the continuity test. I scraped a few dark traces and ran solder over them for good measure. I pretty convinced that around that area is fine.

The Cart Slot 1 looks good also and I have cleaned that.

I think its chip related, I looked in other posts and someone mentioned the 2 bad 74LS245 latches on bottom board. Are they the connectors or the chips next to connector?
 
Last edited:
channelmaniac

channelmaniac

Mr Neo Fix-it
15 Year Member
Joined
Nov 29, 2005
Posts
4,275
You'll need to check follow the traces carrying the data/address lines to the Program ROMs on the cart to the surface mount chipset chips to the connectors that go to the bottom board. From there you can follow the traces from the connectors on the bottom board to find the LS245 chips buffering/latching the data coming in. When you find those you can check them with a logic probe to see if any inputs/outputs are missing data.

I haven't had enough 4F boards come across for repair to have those memorized yet.
 
You must log in or register to reply here.
Top