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My Dying Duo

T

theos911

6502
xx(

I went to startup my Duo 2300c today and had an unsettling surprise. There is no visual at all(or sometimes a brief white screen). I get the startup chime, but it is followed by a sort of scale. It goes through 4 notes, pauses a bit, and continues onto 4 higher notes. These then fade off and it plays some non-harmonizing notes which drift off and then there is no further output from the duo. This is the same in a dock and undocked. I know it isn't the ram expansion card as it is already removed. It worked fine yesterday, so I'm rather lost.

Anyone have any ideas?

 
Is there a modem or an ADB Startup card installed in the modem bay and is it seated properly?

Have you checked that all the internal ribbon cables are seated properly, if not, you might try the unplugging/replugging routine.

Have you got an older Duo so you can test it with a SCSI HDD, a different LCD & related Hardware?

Dunno, maybe there's a catalog of "chimes of death" online as reference material . . . sorry to hear about your troubles.

 
As for the modem, it is in there. I've never used it, so I've no way to know if it has simply gone from not working to system halting. Ribbons are all seated, I have no other duo parts. It does the same thing docked. The HD doesn't spin up(but I think that is a sympton, not the problem or I'd be getting a ? floppy). I'll try and find some more death chime info...

*Although... the chime is pretty sweet for a dead duo; 4 nice notes and then 4 increasingly creepy and weird sounding notes. It fits kinda well for something that is not quite alive, not quite dead :p

EDIT-This is vaguely helpful...

"Everything snapped in well and was basically plug and play. However, on first boot, the machine did the dreaded chimes of death - but there was no Sad Mac. A quick bit of research revealed the longer tones experienced were from the RAM."

Could it be the PRAM battery?

 
I doubt it's the PRAM Bat.

Have you reset the power manager? Hold down the button on the back for about 30 sec. to a minute with the power brick connected, when you let go it should start the boot sequence. That'll revive a PowerBook that's not completely dead, but acts that way in many cases.

Have you got the Service Manual? gamba2

 
*Although... the chime is pretty sweet for a dead duo; 4 nice notes and then 4 increasingly creepy and weird sounding notes.
Click to expand...
I would love to hear the chimes your Duo is producing. The weird sounding chimes is probably linking towards bad ROM, or a faulty capacitor.

 
Reseting power manager didn't do anything. The link to the manual on gamba is broken, but I found one elsewhere.

To quote the manual

RAM failure occurs

(eight-tone error

chord sequence

sounds after startup

chord)

I'm guessing the on-board RAM has died. The expansion card went last week and the on-board this week... something might be off with the memory controller. Assuming it is the on-board RAM, I'm really not sure what to do except for a 130$ logic board replacement.

 
I have a 12MB memory module from my dead 280c. Try to research and see if this would work on it. I could send it to you if you just pay the shipping. Try to find out if that would fit

 
I missed the part about your onboard ram being dead. Will those things power on without the module inserted?
Click to expand...
That is what I was about to ask. I'll test it if I can, but first I need to find out where it is located and see if it still chimes after its removal.

"An optional RAM expansion card plugs into a 70-pin connector on the main logic board.

With the RAM expansion card installed, the processor and memory subsystem supports

up to 56 MB of RAM.

The RAM expansion card for the Macintosh PowerBook Duo 2300c computer is

compatible with the one used in earlier PowerBook Duo models. The computer accepts

up to 48 MB on a RAM expansion card."

So yes, it would fit.

 
Getting at the ram is easy. Remove the screws under the laptop and off comes the keyboard. You should be able to pull out that module then.

I'll see if mine boots w/o the ram real quick.

 
You misunderstood what I said. I don't have an expansion card(read: I had the 12mb that makes it 20mb but it died). That means that the RAM that is bad is the RAM built into the mobo. That is why I needed to know if it will run from only an expansion card.

Here is a link to its messed up startup sound(just uploaded, so maybe not available for a tad)

http://www.youtube.com/watch?v=DtrodJ-8Osw

 
I saw that when it was back at 10$, and I bid on it back when it was 10$. Unfortunately, I have all of 37$ in paypal right now, so it quickly got away from me. (annoying 5 days to transfer funds). And, then there is always that guy who wants 400$ for his broken one. lol

 
if you want to get your hands dirty, and you are for SURE the on-board ram is bad. Remove it and swap it with some new ICs.

 
I don't know what to change out, or where to get the stuff. It has also had an expansion card and on-board go bad which makes me think the memory controller may be bad. And, I'm not, it might be the RAM, or the ROM might be giving a false test or it might be something else. Although, I will soon have a working one due to the generosity of one of our forum goers here.

 
There are several (I forget the number, but maybe 6-8?) small and large aluminum canister capacitors on the 2300c logic board, clustered together to the left of the power connector. The largest ones are of a size to just about touch the top plastics.

I would bet on leaking electrolytics being the cause of the trouble. If so, then your Duo is much more easily repairable than would be the case if the onboard RAM has failed. The replacement capacitors are cheap and plentiful, water to wash the board is on tap, and though a small pain to disassemble, a Duo itself and a capacitor are really not that hard to work on.

 
The weird sounding chimes is probably linking towards bad ROM, or a faulty capacitor.
Click to expand...
those are perfectly normal early PPC "chimes of death" from the description.

 
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