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Fizzbinn

2400c - How to keep it working?

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I took the plunge and picked up a a working PowerBook 2400c/180 of Ebay recently. Any tips on what to check, what to do to keep it functioning? Capacitors an issue?

Edited by Fizzbinn

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Hi Fizzbinn,

 

The 2400c is a good unit, and packs a decent punch in terms of performance compared to desktop Macs of the era.  Capacitors are rarely an issue, but a leaking PRAM battery will probably be present - going off the service manual, you will need to remove the top slider over the keyboard, keyboard and palm rest to view the motherboard.  Clean any green corrosion near where the PRAM battery sits (you need to disassemble the machine almost complete to get the PRAM battery out), and where the battery plugs in can also corrode.  Check also the condition of plastics, by now you'll have taken it apart enough to see if the plastics are brittle and if any degradation is present.  The stock HD is terribly slow, replacing with a faster bigger mechanical drive 40 - 60GB is a good idea, CF-IDE but I've found mSATA to IDE adapters don't work.

 

The rubber feet and those in the LCD panel will probably have turned into goop by now too - all easily replaced. :)

 

Enjoy!

 

JB

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I'm going to self-appoint myself as somewhat as an expert on the 2400 since I have been through so many of them.

 

First, some unabashed adoration: these are probably my favorite of the vintage PowerBooks, certainly my favorite of the pre-WallStreet PPC models, because they have an excellent combination of speed, style, portability, expandability, upgradability, and arguably the best keyboard of any PowerBook (in contention with the 1400 and WS/PDQ, though admittedly the 2400's can be frustrating to people whose stats exceed about 5'6" tall or about 160lbs since the keys are so tiny and closely-spaced, but its firmness, short travel, crisp response, and unique inverted-T arrow keys cannot be ignored). These are generally pretty solid computers compared to their contemporaries: their cases are usually in one piece, the I/O door is usually attached, and they don't normally suffer from any of the hinge-related failures of the rest of the PowerBooks built before or since. The worst thing about them is that the floppy drive usually isn't included anymore, and since it's a model-specific unit with a special cable it's kind of a pain to replace. They also came with a special small 2400-specific power adapter that may have been lost and replaced at some point with a yo-yo or one of the big bricks from the 1400 or 3400. You can readily use one of the replacement adapters, of course, but the matching smallness of the original adapter helps make the set.

 

The big failure points on these (and other models with the pea pod-esque NiMH PRAM battery such as the 3400) are undoubtedly the PRAM batteries, which leak and destroy the logic board, and also LCD panel degradation, primarily suspected to be the result of poor environmental storage (too hot and humid, possibly stored alongside certain chemicals or with no ventilation). These problems are not unique to the 2400 since I have stacks of computers and other devices with leaked batteries and bubbled-up LCD panels. With preventative maintenance and proper storage you can likely avoid these problems, though.

As with most PowerBooks, capacitors are generally solid except for a handful of tanks in the power supply section. They usually don't cause problems, especially here on the 2400's charge card since most of them are excellent Sanyo OSCON types rather than the standard electrolytics usually populating most computers. IBM Japan did an excellent job engineering these and sourcing quality components.

However, small problems you're likely to experience will be total degradation of the rubber bumpers on both the main unit and the floppy drive, the floppy drive door missing or with busted hinges (I'd say 90% of these are broken by now), missing screw covers on the clutch cover bar, trackpad button unresponsive or otherwise uncooperative, and occasionally broken I/O doors or display latches.

Full disassembly is required to remove the PRAM battery. I never bother to replace them, simply remove them, because a. they're an additional expense; b. the new ones are likely going to go bad in another decade or so necessitating further surgery on equipment that may be too brittle to endure it; and c. I never use them often enough for the battery to be effective: either the computer is plugged in/has a charged main battery while I use it, or it's in storage where the battery will be depleted in a week or so anyway. If I was a road warrior in 1997 and was sleep-swapping the main batteries on the go, yeah, a good PRAM battery would be essential. But they're hobbyist playthings at this point so it's not important. You have to use weird workarounds for the proper day and time to be displayed in classic Mac OS anymore anyway.

 

While you're in there you can replace the hard drive as mentioned with something a little more spacious and faster. You may notice that there's a raised area with a thermal pad on the shielding beneath the hard drive. Obviously a modern 9.5mm drive won't contact this so the drive may run a smidge warmer than the original 12.5mm drive would have, since the original drive would have been making contact with the thermal pad to aid in heat dissipation. Anyway if you plan to use SCSI Disk Mode, ensure you partition the first 4GB of the drive and only use that when connected to a different Mac or you'll get massive data corruption on anything past the 4GB partition (the host Mac will mount all partitions, so just eject everything except the first 4GB partition and you'll be fine). This is true of any pre-G3 IDE PowerBook owing to a ROM bug; there's no getting around it. 

You can hack it to support CardBus, depending on your specific logic board revision, by either removing the two yellow wires above the RAM slot to the right of the ROM chips, or unsoldering C375 and C377 in the same general area. 

You can also install a G3 upgrade if you can find one that's reasonably priced. The 320MHz and especially the 400MHz ones are rarest and most expensive and were primarily sold in Japan, but the 240MHz ones show up on eBay every now and again.

If you want to upgrade RAM, the official maximum is 80MB using a 64MB EDO SODIMM, but there exists a custom 96MB SODIMM that's about as common as the G3 upgrades, and that will take you up to 112MB. This combination would allow you to boot OS X via XPostFacto if you're into it. However, DO NOT try to use a normal SDRAM SODIMM or you may burn something up since voltages are different.

Speaking of burning something up, the logic board and power card on those things are littered with fuses. If you have a problem with something (no boot, no hard drive, no battery charge, etc), check your fuses. Usually the bad ones will have a black dot in the middle but you'll want to check with a multimeter anyway.

The trackpad clicker is always a little loose-feeling. Originally there were some foam pads underneath it to reduce this but they've turned to powder after 20-some years. If it's not working the button assembly itself can be cleaned but it's a touchy job. To clean it, you'll have to disassemble the trackpad, unstick the ribbon cable assembly, carefully peel back the clear tape over the button contacts, remove the flexible metal button from the tape, and clean both the underside of the flexible button and the contact on the ribbon cable base without damaging the tape. Then you'll have to reposition the button atop the base contact and reapply the tape without skewing the button or pressing too hard on it. Alternatively you can replace the button with a different physical button but this involves some soldering and careful selection of a new button/modification of the clicker post to get it to fit properly. To prevent damage to the clicker button once you've repaired it, replace the bumpers on the LCD panel and/or don't close the lid; excessive pressure on the button while the lid is closed is usually what damages the button in the first place.

The LCD panel is an IBM 11.4" CTFT unit unique to the 2400c (at least among other Macs), so try not to hurt it because replacements are not easy to source.

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On 4/15/2020 at 12:23 AM, Byrd said:

The rubber feet and those in the LCD panel will probably have turned into goop by now too - all easily replaced. :)

Are they easy to replace or was that sarcasm? I'm thinking the later but I got to ask since that would be great if there was some way to obtain/make replacements.

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@Franklinstein Wow thanks for all the info! Mine included the original 2400-specific power adapter and floppy drive with cable (although the hinged front door on the floppy is gone). Its such a neat form factor and does seem pretty sturdy (especially compared to the 1400 I have.

 

I haven't taken mine apart yet, but removing the PRAM battery is on my list. The main battery I have seems to hold a charge, but I haven't tried to run off it for more than a couple minutes, in other threads it sounds like some are reporting the 2400 needs a working main battery or PRAM battery in order to boot, in your experience is that true? Perhaps their non-booting problems are really about one or more failed fuses?

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On 5/1/2020 at 4:24 AM, Fizzbinn said:

Are they easy to replace or was that sarcasm? I'm thinking the later but I got to ask since that would be great if there was some way to obtain/make replacements.

 

Easy to replace.  A hardware store will probably sell clear round equivalent sizes for the bottom of the 2400c, the rubber caps on the screws I'd not bother with as they are a pain to remove and you can potentially damage the plastic as you pry them out.

 

You don't need a working PRAM battery for the 2400c to boot.

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One of the "infamous" problems with the 2400 (and many other contemporary PowerBooks) is referred to as the "Green Light of Death" (a.k.a. GLoD), where the computer doesn't do anything except cycle the sleep LED on/off. This is caused primarily by two things: 1. a partially-dead PRAM battery that holds just enough charge for the contents of the power manager's RAM to become corrupted, preventing boot without several power manager reset cycles (not a huge deal, just really annoying); and 2. a serious hardware problem somewhere that will need attention (a bigger deal, usually caused by a leaked PRAM battery and/or improperly installed components following an upgrade or maybe a big drop). Removing the PRAM battery will prevent GLoD caused by point 1 but won't do much for point 2, especially if it has already leaked everywhere. However, without a PRAM battery and a charged main battery, the computer will instantly power up immediately after it's plugged in. You'll also lose date/time settings if the computer is unplugged without a charged main battery, too.

 

The only computers that really have problems booting without good PRAM batteries are the 6-slot Mac II models (won't power up at all) and the 6100 (won't boot without pressing the reset button after power-on), though the LC475/Q605 may also be fussy without one (may not boot without quickly flipping the power switch on-off-on to jump-start the CUDA); most other machines function just fine without them. Many of the PowerBook G3 and G4 models won't power up if their PRAM batteries are dead, but will work fine if they're missing.

 

You should try to find replacements for the display bumpers because without them there's too much pressure on the trackpad clicker with the display closed, which can cause it to quit working properly. I don't really have a source for replacements.

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I got the PRAM battery removed (hadn’t burst yet), the disassembly wasn’t too bad actually. I wish the PB 1400 had hinges this well designed. It’s funny to see all the IBM marked parts. 
 

I did take the opportunity to replace the original 1.3GB hard drive. I used an IDE to mSATA adapter that I’ve successfully used in my PB G3 Pismo, iBook G4, Mac Mini G4 and PM 7300 with Sonnet Tempo PCI card. I actually stole the one from my 7300 since I wasn’t sure it would work well and it’ll be much easier to replace in the 7300 if it did. I had tried this same setup in my PB 1400 with different results, it technically worked, but there were weird writing performance issues (I settled on an IDE to Compact Flash adapter for the 1400). Disk performance is great now, a SpeedTools benchmark has reads around 10.5MB/s and writes at 8.5MB/s. Unfortunately I didn’t run a test with the old drive. ...I guess I could put it back in for a comparison test, could be interesting to see what a 40GB spinning disk could do as well...

 

In case anyone is interested, here are the replacement HD parts I’m using:


Ableconn IIDE-MSAT mSATA SSD to 2.5-Inch IDE Adapter Converter -$31

https://www.amazon.com/gp/product/B017VQT5YW/

 

Transcend 32GB SATA III 6Gb/s MSA370 mSATA Solid State Drive (TS32GMSA370) - $38
https://www.amazon.com/Transcend-MSA370-mSATA-Solid-TS32GMSA370/dp/B00K64HXRS/

(I wouldn’t buy this one again today, price has gone up, I got mine for $20, there are other options that cheap now though) 

 

 

Edited by Fizzbinn

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I'm also about to go down this journey with a Powerbook 2400c/180 that's on it's way to me from Japan. 

 

I wanted to thank Franklinstein for sharing that information and @Fizzbinn for the information on the CF-IDE.  :)

Edited by ncr

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I think I jinxed myself by starting this thread! I can’t get my “new” 2400 to start up after being on the shelf for three weeks...
 

I tried resetting the power manger to no avail:

http://www.jacsoft.co.nz/Tech_Notes/PP_Manage.shtml#faq7


When I plug in a power adapter (tested good on my 1400) I hear a small click sound, pressing the power key does nothing. Pressing the resets but on the back does nothing. 

 

The PRAM battery was removed shortly after I got it but I did have a battery installed that seemed to be holding a charge, I wonder if that failed and did some damage not visibly noticeable? Failed power board? Blown fuse somehow?  
 

I’d greatly appreciate any thoughts or ideas to try :-/ 

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I have a voodoo trick that works on mine. 
Try leaving it plugged in for a few hours so the battery charges. Then disconnect the power adapter, and remove the battery. Then, holding down the power button, push the battery back in.

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Usually just removing the battery and leaving it unplugged for a day is enough to let everything settle back to zero and be ready to go when you plug it back in. You may also need to try several 30- to 60-second power manager button resets (meaning hold the button down continuously for up to 60 seconds) with and without the power adapter plugged in. Eventually it should come back to life and you should figure out what sort of sequence it requires should it decide to stop working again.

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I have 3 great condition PB 2400’s and really don’t want to pull the PRAM’s out on them. The take apart is just a real pain. And to do three is just eyeboggling. I don’t think any have leaked yet but they have to come out. I agree with said earlier I NEVER replace any PRAM batteries. This was primarily for during the time they were used daily way back when. ALL batteries are removed from my machines out or in storage! It should be common practice amongst us collectors. I’m just dredging taking them out of these three.. I absolutely hate the take apart. But my laziness to leave them in will pinch me later on down the road... 

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Well I did it.... got all three ticking time bombs out! It’s important that first order of business with classic Macs is to remove the PRAM battery! Leaving them in and or replacing them and forgetting them can destroy your classic Mac!!

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On 4/30/2020 at 6:29 AM, Franklinstein said:

 

As with most PowerBooks, capacitors are generally solid except for a handful of tanks in the power supply section. They usually don't cause problems, especially here on the 2400's charge card since most of them are excellent Sanyo OSCON types rather than the standard electrolytics usually populating most computers. IBM Japan did an excellent job engineering these and sourcing quality components.

This is great info! I didn't realize they used polymer caps in these. Curious how many of them are electrolytic.

 

Thanks for the massive post; I got a 2400c a few months ago and have it working really well now (PRAM battery removed of course). 

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I guess I should have said "most modern PowerBooks" because most of the pre-PCI models were often full of electrolytics. The 3400 had many electrolytics but these were mostly only present on the charge card. Other later PowerBooks were the same though I don't know the exact configurations of most of the newer ones. I do know the iBooks used a large electrolytic supercap to momentarily retain NVRAM should the main battery be swapped out when shut down (they aren't meant to be sleep-swapped). 

 

The 2400, however, is the only one of this era that used the OSCON polymer caps instead of normal electrolytics on the charge card (and the ones on the logic board were all solid types). The power brick probably still has normal electrolytics, though, and the display may have one or two as well; I haven't looked.

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