After a few hours, ~6-8 hours, of uptime, one of these 3d issues would happen:
The female T-Rex would load wrong textures on some parts of the jaw and inside the mouth.
The 3d graphics would flicker.
No 3d graphics would show at all.
My initial thought was the boards weren't receiving the proper airflow due to some caked dust so I cleaned out the cage and boards; didn't fix the issue. Memory test shows rom and ram all good but displays a vertical dashed line of white pixels (disappears upon exiting the test mode however). I have not checked the voltages from the power supply yet. Could this be a video board issue?
If anyone else knows about Model 3, I noticed there is no mention of a step 1.5 on both the cpu and video boards of this Lost World boardset. I heard the only difference is the gpu overclocked on the video board. I'll save this discussion for a different thread.
Difficult to say, most likely a video board issue but step 1.5 video boards are more reliable than step 2 boards in my experience.
Could also be the ROM board so worth trying a different game on the stack if you can.
Always worth checking voltages particularly if you have an original Model 3 PSU which are known to be unreliable when they get old. A known 100% worker or better still a Sun PSU out of a Naomi is a better option.
For info step 1.5 boards just have 'Model 3 etc.' marked on them while step 2.0 and step 2.1 boards have 'Model 3 Step 2 etc.' marked on them. The .x isn't mentioned.
Wanted:
Sega Model 3 Emergency Call Ambulance ROM board or complete Step 2 boardset.
My most likely guess is a certain component eventually shutting down from improper voltage and/or overheating. My next steps are to reseat/clean all the roms on the rom board, check/adjust power supply voltages and replace both fans. I'd appreciate any good suggestions for Sega Model 3 fan replacements, two of them.
Lowered the +5v and +3.3v down to near normal values. The issue got worse a few days after with the game freezing ~20 minutes after startup. My next step is now to check all boards and replace the fans.
Nobody has any suggestions for replacing the case fans on a Sega Model 3? C'mon guys. I'm certain one of you has replaced them before and the factory fans can't last forever.
EDIT: May take a look at the whole pcb set one day so I can find out what fans are used.
Last edited by Hydreigon on June 15th, 2019, 6:37 pm, edited 1 time in total.