Recent content by MagicianLord77

Hi guys, I find myself with this Sega Naomi board that has let me down. It's my first and only Naomi board, I know it used to work, then was stored at a not very dry place for around 2 years, then came to my hands to seem to perfectly work for a couple of hours then hang in game - screen froze...

Hi, found the EC34 capacitor value at the motherboard service manual, page 21: C10U16EL, I would decode that as as a 10 uF 16V cap Also got an almost discernible image of it, from a MSI MS-7142 photo, has a similar VIA VT1617A audio section

Here are Sega Star Jacker schematics that I've seen others use to repair Wonderboy: https://drive.google.com/file/d/1AYv91Pfp4V8LqV062SefD2vPYrT73zQM/view About the 74LS157s, the usual thing to check is for stuck/nc outputs (pins 4, 7, 9, 12): https://eater.net/datasheets/74ls157.pdf. If you...

Hi, those RAMs you replaced might be work rams, if you turn on the game w/o them, does it boot up?. If those ROMs are good, and you're sure they're related to the failing sprites, with a multimeter you could check what's the destination of their data lines, they could go to a failing logic IC...

Hi all, got a MK4 board that reports "Error 0A - Sound System Error - SRAM Failure" on boot, after that it plays fine, without sound. When it displayed that message it did bong a few times, so that would at least mean the DAC and AMP would be ok. Began by verifying the sound roms with a XGecu...

Hi there, I'm looking for just a Mortal Kombat 2 main pcb in good working condition, I already have a working sound board (my main pcb is not working good). It could be either a MK2 or MK1 (T-Unit). Shipping to US. Thanks!

@wickerwaka Thank you for sharing your research. It inspired me to go try convert my Gunforce into In The Hunt. Desoldered 9 32 pin roms, installed sockets in their places Programmed the ITH rom set + decrypted sound rom + M92_B-7H-D GAL Set up jumpers accordingly Success!

I was googling for schematics for a Tekken 2 (System 11) motherboard I have with issues and your post just showed up, for me this document makes the difference between being able to continue troubleshooting the board and hopefully finding the issue or throwing it into the parts bin for maybe...

Same flawless experience with my Volfied PCB purchase. Thanks!

Fixed. The uPD7759 was bad. Posted full repair log at https://www.arcade-projects.com/threads/konami-tmnt-repair-g8-bad-051960-custom-replacement-intro-song-speech-sound-issues.28624/

Hi guys, I got hold of an untested Konami TMNT PCB. Initial inspection was good, looks alright after cleaning with brush, no scratches with broken traces, notable details are just 2 socketed SRAMs (G8 and F23) and quite some soldering glob over each JAMMA pin, seems they were a bit...

Update: took out, tested and socketed: F15 (74LS273) used for choosing which sound to play, input comes from Z80 data bus B16 (74LS273) used for addressing high ROM address lines D18 (1Mbit mask rom) They all tested fine using Xgecu T48. Replaced the LS273 with other ones just in case had a...

Hi guys, I'm looking for some assistance on bringing this Konami TMNT board back from the dead. Got it from an arcade parts lot. It had different issues that I've been able to overcome, but got stuck on this one. Previous issues were: G8 BAD error - fixed replacing 051960 custom Title music...

Thanks. Today I reflowed the data port pins, took out U16 (DAC), U37 (TL084), U18 (74LS74) and U38 (74HC14), installed sockets. Tested the U18 and U38 on the T48, not surprisingly reported good. Installed a GoldStar 74LS74 at U37 just in case. Replaced the TL084 with a new one since it was cheap...

Hi guys, I'm having a bit of a struggle with the sound board of my MK II, game works fine, but sound board never gets to boot up properly, its LED rarely turns on. When started up or reset, most times it does something different, I mean I might get no bong, or 1, with all roms installed, prior...