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PB2400c doesn't boot. Is there anything useful information to fix it?

Kamomr

New member
Recently I got PB2400c from Yahoo Auction about $60. It was listed as junk, but cosmetically it seems okay, so I did bet.

After I got it, I disassembled it, and found some not-so-good situations.

1. Green crystals. Yes. PRAM battery has gone really bad. Fortunately, most of battery acid was on inner frame, and there are no visible corrosion on logic board and CPU daughter board.

2. Some of logic board screws are quite stripped. I did almost everything to undo them. Drilled to remove head, smack brass insert from back of frame to remove with inserts. All failed. Eventually, I cut inner frame to release brass insert.

However, I was able to completely disassemble and cleaned battery acid from my unit as much I can, and reassembled.

Now, second problem was I didn't have power adapter for PB2400c. So, I bought off-the-shelf 24V 2A DC adapter, and soldered 3.5mm stereo plug to build makeshift PSU.

When I connected power to unit, LED on display cover lit, but didn't response to power key.

I can hear little click sound from speaker when I press reset button located in back IO section, but still no sign of booting. I tried PMU/PRAM reset, but still no luck.

If I push reset button repeatedly, it keep cycling between green LED <-> speaker click.

During researching, I stumbled upon SMT fuses from this community. So I tested all fuses with multimeter and inspected visually, all fuses were okay.

I completely disassembled and rebuild it several times, but still nope.

It seems some kind of power is flowing through because when I put it still my unit after I hear speaker click, it became warm on the bottom.

At this point, I got little tired with my unit. It seems this thing is really broke, so only way to get working PB2400c is get one with smashed display or pay $700 for one equipped with G3/320 card. That's waaaay to much for me.

Is there any useful material to troubleshoot and fix my unit?

If not, I'm considering to sell this one as parts and get PB G3 or something can run classic Mac OS.

P.S. I was thinking to get 68K PB, but 2.5" SCSI HDD is keep away me to get one. Darn SCSI!

 
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beachycove

Well-known member
Most of these 2400c units will not boot without a functional backup battery (the green crystals). You just get the “Green Light of Death,” appropriately enough. Search “GLOD PowerBook,” and all shall be revealed, but the 2400c is the worst offender of them all. Notoriously so.

A backup battery can be assembled from a couple of Varta cells easily enough. I have a posting in here somewhere from years ago with the number. What may not be so easy is disassembling your 2400c to get at the area!

I might be interested in a parts machine, btw. Where did you see one for sale with broken screen?

 
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Fizzbinn

Well-known member
Most of these 2400c units will not boot without a functional backup battery
I thought the 2400c didn’t care if you removed the backup battery? In another recent post it was stated that the 3400c works fine without one and architecturally the are quite similar.





If the 2400c does require (or even benefit from) having a functioning backup battery I’m def going to look into building one ASAP! I removed it from my working 2400c for fear of it leaking and not to long after I could get it to boot.  I assumed other faults must have existed but if it’s “just” the backup battery...

 
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Byrd

Well-known member
Confirming no need for functional PRAM battery in 2400c; it doesn't need one to be reliable.  Also difficult to replace based on the tiny little area of plastic moulding one is supposed to fit into.

 

KnobsNSwitches

Well-known member
Just another confirmation for no need for a pram battery on the 2400 - I have been running fine without for a couple years now. 

 

Kamomr

New member
Most of these 2400c units will not boot without a functional backup battery (the green crystals). You just get the “Green Light of Death,” appropriately enough. Search “GLOD PowerBook,” and all shall be revealed, but the 2400c is the worst offender of them all. Notoriously so.

A backup battery can be assembled from a couple of Varta cells easily enough. I have a posting in here somewhere from years ago with the number. What may not be so easy is disassembling your 2400c to get at the area!

I might be interested in a parts machine, btw. Where did you see one for sale with broken screen?


I saw couple of posts that I need PRAM battery to boot, and others said opposite.

However, at this point I'll give it a try. I think I have some Varta cells around cabinet I bought to replace old Toshiba laptop's CMOS battery.

 

beachycove

Well-known member
The GLOD problem was erratic, with machines working some of the time, when the moon was full at Spring tides in leap years, with Mars bright in the night sky. Whatever. Perhaps the “most” in that post was an overstatement, but I certainly had one that absolutely refused to boot without a functional backup battery. GLOD all the way! And it was tried with no battery. It was apart ten or twelve times to access the internals, clean things up, and replace boards even. All it needed in the end was a ruddy battery.

The machine was designed to run with that battery preserving settings. Replacing it is a cheap and arguably the easiest option to explore in trying to get the thing running. That was my experience, and I think it is worth a shot here, even if the trouble turns out to lie deeper in the hardware.

 
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