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Monitor Repair Log and Database. **Arcade and Gaming** => Monitor Repair Tech Support => Topic started by: indiana cards fan on October 07, 2011, 05:53:33 PM



Title: neo geo 4 slot
Post by: indiana cards fan on October 07, 2011, 05:53:33 PM
Hi,it is me again thanks for the help on trying to figure out the neo "sound problem "without a monitor! Capped a monitor and looks great. But cross hatch pattern comes up and can not get out of test mode? All seem to work except sound is "off" can not toggle that to on? And get it to go into game mode,with some cartridges in,all out, 1 in etc. Test switch is by the coin door,is there another one that is on board before I take the whole thing apart ? All dips are like they should be[ think on] Thanks Bruce


Title: Re: neo geo 4 slot
Post by: channelmaniac on October 08, 2011, 01:33:20 AM
Take the top board off the bottom board and look at the battery hidden in there... 2:1 says it's leaking and has damaged the traces under/next to it that lead to the connector that is next to it as well.

If those traces are eaten through then the data bus for the program ROMs won't carry all the data back to the CPU and thus it thinks there are no cartridges installed.

Follow the traces, check continuity, and patch the bad ones.

RJ


Title: Re: neo geo 4 slot
Post by: indiana cards fan on October 10, 2011, 02:58:50 PM
Hi would I be correct in that battery is not putting out 3.6 volts .That it would cause the same problem[staying in test mode]?Also If unable to find one local any tips on replacing it,I can "jury rig" something to hold any comparable battery?
 Thanks..Bruce


Title: Re: neo geo 4 slot
Post by: channelmaniac on October 11, 2011, 02:44:08 AM
If the battery hasn't leaked and damaged the board... you might have overlooked the simple thing of making sure the DIP switches are all off. ;)


Title: Re: neo geo 4 slot
Post by: indiana cards fan on October 11, 2011, 11:05:18 AM
Well now I have no clue.I suppose I will check switches again.Pretty sure like I said earlier they are all on .To restate problem;cross hatch screen comes up and stays on ,does not go to screen with "exit" on it so have no way to get it to go to game mode at all ,other "steps" of programing ,setting date etc all work except I notice that can not toggle sound on or off[stays off]. With one cartridge  in,2, 3 , 4 , or no cartridges in?Pretty sure carts are good? If all bad would it have this problem? Thanks again,sorry about this problem ,!!! Hoping it is simple!


Title: Re: neo geo 4 slot
Post by: channelmaniac on October 11, 2011, 11:18:46 AM
Reset the backup RAM - it's one of the menu options in the test section you are stuck in.

Check the volume control and make sure it's turned up...

If still no volume you'll most likely need to replace the electrolytic caps in the audio section of the board. It's a common problem. So common that I put together and sell a cap kit for that on my web site.

Have you taken the battery off the bottom board yet and checked for corrosion damage to the traces running to the connector next to it? That's another very common issue that causes you to be stuck at test...

Also, have you cleaned the cartridges yet? Disassemble them and scrub the edge connectors with a big pink pencil eraser.

RJ


Title: Re: neo geo 4 slot
Post by: indiana cards fan on October 11, 2011, 10:09:15 PM
Hi,thanks for your help! Will try taking battery out and checking that.The sound is not an issue right now[but if I get it out of test mode,will get the kit].Back up ram ,portion of test menu,I tried that earlier also;pressed all 3 buttons to clear,and no reaction? Checked resistance on dip swithes [thinking # 1 is shorted;seemed to check out ok]. Have not tried to clean a cart. yet. So if a bad cart is in that also causes it to stay in test mode? Thanks again!  :103-


Title: Re: neo geo 4 slot
Post by: channelmaniac on October 12, 2011, 01:36:05 AM
The system tries to read the carts... if it cannot then you get the crosshatch screen.

Have you looked closely at the top board to see if you have corrosion damage? It's something that happens when spills or rodents interact with game boards...