X68000 XVI - Refusing to boot after turning off - Weird noises

[PadPoet]

Hi everyone,

I've been a lurker for like forever but decided to join the forums since I am facing problems with my X68000 XVI machine.

The PSU on this machine was replaced with a 240V one. I was testing the machine loading a bunch of games from an external SCSI to SD hard drive and everything was going great.

Suddenly when I turned off the machine, after 30-40 seconds I heard a loud bang. Checked to see if anything had fallen to the floor but was curious to see if any fuse was blown and yup, the X68000 XVI was not booting.

I replaced the 3A fuse in the power cord and when I switched the on button on the back I heard again a loud bang/sound like plastic cracking from inside the machine.

I'm a bit scared of changing fuses again, don't really know what to do. Should I open it up? Does these tutorial videos for disassembly apply to the X68000 XVI as well?

https://www.youtube.com/watch?v=LuYx58ZqxgQ
https://www.youtube.com/watch?v=N4SkiebPoZ8
https://www.youtube.com/watch?v=G8D9aJab8fY
https://www.youtube.com/watch?v=MXJhbHWx6hM

Thank you all

[Spitko]

Autopsy time.

You need to open that sucker up, and take some pictures for our amusement!

Really though, sounds like your PSU has catastrophically failed. Did Sharp make 240v power supplys in some markets, or is this some kind of aftermarket job? If the latter, I can't really tell you much more without knowing what you have and how it's made.

With any luck, the damage may be localized to the power supply itself, and the rest of the 68k might be fine; however DO NOT UNDER ANY CIRCUMSTANCE PLUG IT BACK IN OR REPLACE THE FUSE. All you'll do is increase the odds it takes something expensive and hard to replace out with it.

To get to the power supply, the first "General disassembly" video shows most of the tricks you'll need.

• Remove the left tower cover (the side with the floppy drives).
  
• Disconnect the two power connectors on the floppy drive.
  
• Disconnect the HDD power connector (if equipped)
  
• Remove SCSI sub-board. It's the piece with a bunch of ribbon cables plugged into it, between the bottom of the case and the power supply. To do this, you'll need to remove the two ribbon cables (there should be release tabs for both cables), then remove two screws and lift the module out
  
• Disconnect the main power connector. This is a 5(?) pin job at the bottom, it has a small latch you need to press while pulling the cable out; the notch faces inward.
  
• Finally, remove the right side tower cover, and disconnect the two pin SUB_POWER connector. You'll find it near the bottom of the board. Feed this through the hole between the two towers, and pull it through.
  
• Now remove the two top screws holding the PSU in, and you should be able to freely remove the module. Opening the module itself should be a case of simply removing all exterior screws. The only screw you can leave in is the lower of the two countersunk screws; but it's fine if you remove it (Just make sure you re-install it. There's a clasp on the other end that holds a transistor package against the side for heat sinking)
  

[ashrion]

You have a mod to 240v that has shorted.
That goes directly to the computer, you have destroyed something, the luck you have is that they are extremely well protected against short circuits, then you have to find what has failed and if you have repair do it and then replace the fuses encapsulated.
Right now you have the fuse of the scsi board and the fuse of an address of the scsi inlet of the bottom plate dead.
Go to know that you have broken