Mostly dead Duo 230 - makes hissing noises!

[bigmessowires]

A friend gifted me a working Duo 230 that he rescued from a trash bin. We got it to my house, and it booted up fine. System 7.1, 12 MB RAM, 120 MB hard drive, 16 glorious grays.

We left the computer sitting for about 30 minutes, and when we returned, the screen was dark. Now nothing will make the Duo boot. I've tried it with and without the battery inserted, tried pressing the power button above-right the keyboard, and tried pressing the power button on the back next to the dock connector.

Here's the weird thing: as soon as the AC adapter is connected, the Duo makes a short hissing noise from the speaker, every 4 seconds. If I hold down the power switch on the back, it makes the hissing noise continuously as long as I hold it. If I press the power switch above-right the keyboard, though, it has no effect.

Anyone have any great ideas for other things to try, before I return this machine to the trash bin? This is the same friend who loaned me a working SE/30 that promptly broke in my care, so I'm developing a bad track record here.

 

[techknight]

try another AC adapter. sounds like it failed.

 

[theos911]

Duos do all sorts of funky crap when their PRAM battery is only partially charged(Chime w/no boot, intermittent booting, weird sounds, etc). I have a 230/70c/80c/300c and it's true for everyone of them. Try removing the PRAM battery and see if it boots. It should boot without it, but you'll eventually want to get another battery.

 

[bigmessowires]

How does one get access to the PRAM battery? I searched for "Duo 230 disassembly" and similar, but came up empty. Do I need to undo all the screws on the bottom and take the whole thing apart, or is there some simple way to pop out the trackball and keyboard?

 

[bigmessowires]

That was it! I unscrewed all the screws on the bottom cover, lifted out the keyboard, and disconnected the PRAM battery. Now I'm back in business!

Lots of weird screen ghosting, but it works. I don't have a dock or any way to get anything on or off it, though. Looks like an Appletalk connection will be the simplest solution.

 

[classic]

Nice one for the resuscitation!

Those grayscale passive matrix screens always are a bit ghostlike..

If you can get a hold of one, an HDI-30 SCSI cable, System 7 and SCSI disk mode will be a quicker method of file transfer than AppleTalk.

+ you can check the Duo 230 HDD for errors from the desktop machine.

 

[bigmessowires]

Right, but you need a dock to get the HDI-30 SCSI port. Unless I'm missing something, the built-in Appletalk port is the only way to move data in and out of a Duo without a dock.

 

[classic]

My mistake!

I am such a )

Definitely the novice around here.

I must have confused the port with this one:

http://www.forcedperfect.net/hardware/other/macintoshhdi20externalfdd/