hi folks, I have a very stange sound problem with one of my AES carts but here is the full explanation: I have 3 AES games(Metal Slug 3 US,Metal Slug X JAP,Garou MOTW JAP) and an US Neo Geo AES console with a very low serial number(I think,this is one of the very first US rental models ever made),without unibios and with the first POW with 5 V. Garou(JAP) and Metal Slug 3(US) work without any problems but my japanese Metal Slug X has sound issues,always at the same locations in the game: during the first boss battle,during the entire second level(it gets worse when I proceed in the pyramid) and during the final boss battle. I bought the japanese MSX a few years ago from a japanese collector/seller and it is more or less guaranteed,that this one is a 100% original and authentic SNK product. I explained the problem but he said,that he tested the game before selling with his japanese(!) AES console,and there was no sound issue. he had another MSX so I sent back my copy and received another MSX from him. he tested the game for several hours and finished it multiple times,before he sent it to me and it worked perfectly. but then again...the second MSX(which I still have) showed exactly(!!!!!!!) the same sound problems at the same spots in the game. the second MSX was not in the exact same condition as the first,so he send me indeed another copy and not the same one back. both MSX carts were never opened and show absolutely zero signs of damage at the usual "opening-sides" and nothing is "loose" inside.both games were complete with insert,baggy,manual and registry card. so I can say for sure,that this is not a bootleg,conversion or any kind of neogeofreak-crap. this is the authentic original jap AES cart. testing the game with a japanese AES console would answer the entire sound question instantly,but I dont want to buy an extra console just for testing one game. the hole thing sounds like a cold solder on the MSX pcb inside the cartridge but it worked on the sellers japanese AES system,so it cant be a solder problem. now my question: unfortunately,I dont have the possibility to test my MSX with a japanese console so is it possible,that the low serial US console with the 5V cannot handle the special chips used on the japanese MSX pcb properly? any experiences here in the forum with a first run AES unmodded US console + JAP Metal Slug X?
If you suspect the 5V power supply is insufficient you just need to find another power supply that is the same polarity, voltage, and jack size that can provide more amperage. From what you describe it sounds like the cartridge should be fine and it's the console having an issue. Different cartridges can have different power requirements. But it's odd that the problems would be triggered on a specific point in the game. That makes me think it's not a power issue. If it's something you wanted to do anyway, you could try seeing if UniBIOS would fix the issue if it's some kind of BIOS issue. Otherwise a bigger PSU or a different console are the only things I can think of to try.
I will try to find a cheap jap console to test the game and finally solve this weird sound issue with my MSX. but I think,I will keep my US console unmodified.this is the very first run of the US model and therefore pretty rare.and besides that,it works perfectly with my other AES carts.its only the MSX,which makes (sound)problems. but thanks for your post
