And now we arrive to the real issue at hand, of which I only recalled being a part of the original issue when I was given the cabinet. Before it became completely unresponsive for Jeff, it would sometimes take 3-4 boot cycles to actually get the game to display and/or needed a lengthy warm up time and then a reboot. After the recap, I was now experiencing this same issue. Although in more of my tests no pattern seemed to emerge from what I could see.
In the morning, before I did the deep clean and gun repair in the previous posts, I ran through a few preliminaries and heres what I found:
- Cold boot after 12 hours, initially started up just fine but froze after 3-4 minutes. Black screen, start button lights stuck solid instead of flashing
- All fans were running fine and nothing seemed overly hot on the motherboard.
- Left powered off for 5 minutes, nothing on repower.
After this, I let it sit for awhile as I did my full cleaning and reseated all connectors in the hope that just one was loose or funky which would be causing my issues. Once that was done I reinstalled the board and attempted boot again, but no luck. I let the board sit for awhile as I ran out to do a repair job and picked it back up when I came back about 4 hours later.
Doing a sanity check, I ran a few boots without the game cartridge inside to see if I could get a bios screen, more on that later, but still no response. I wanted to test voltage rails once more time while I had the board sitting in an unresponsive state when suddenly, after about 7 minutes of it sitting at a black screen, it booted into the game. Confused, I continued to run tests including testing the 5 oscillators on the board where it crashed again after about 30 minutes of testing. I kept running test during this and then decided to power cycle it again to run some memory tests if I could get back into the menu. Surprisingly I had an almost 100% boot success rate after this for the rest of the night, almost.
I ran 5 back to back passes of RAM and ROM tests twice, one batch from a cold boot and one after 12 minutes of attract mode, both came back 100% with no reported faults or errors. While I had a good stroke of luck with booting I wanted to see if I could see the Naomi BIOS screen by removing the game cartridge. Come to find out the 1st gen Naomi, which HOTD2 uses as its the first game to utilize this platform, does not have a dedicated BIOS screen, you can only access test menus when you are already booted into a game environment. This was further confirmed by the fact that I was able to boot back into the game immediately once I reinstalled the game board and could access all test menus once again.
Coming off of this information I decided to do a soak test, let the game sit in attract mode for over an hour and see if we got a freeze, crash, or any abnormalities. To my surprise, nothing of the sort happen. We played a few games to push the motherboard a bit harder but we were able to play just find (outside of the guns not being calibrated correctly, but thats a later issue).
For one final test for the night I wanted to do a cool down test to see if I would get any different results from letting the board cool in between power cycles. The test report is as follows:
- 5 seconds off, Boot
- 30 seconds off, Boot
- 2 minutes off, Boot
- 5 minutes off, Boot
- 10 minutes off, No Boot.
- It booted about 1 minute later after pressing PSW2 on the filter board, not sure if related
- Another 10 minutes off, Boot
With seemingly no pattern or correlation between tests, issues, replacements, etc. I'm beginning to worry that this board might just be failing at its core. I'm going to continue to try different tests and solutions to hopefully get this board in 100% working order.
Sidenote, I also figured out that this board has a Japanese BIOS rom installed despite all of the test menus being in English (the tooltips in HOTD show in japanese), so I have a new region free BIOS coming in the mail. Maybe a BIOS chip replacement will let all of these issues go away, a man can dream!
