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PowerBook 5300 Power/DC Board Recap

3lectr1cPPC

Well-known member
The PowerBook 5300/190 series Power/DC Board is just a capacitor disaster waiting to happen. A total of 12 surface-mount electrolytics, 11 of which are very large, sitting there, in neat rows, waiting to spill their guts out whenever the rubber seal decides to disintegrate. I've heard that these boards can be rather unreliable (no surprise there), but I've been lucky so far. I have 2 that both work, although both have damaged battery contacts from 2 separate leaks. As a challenge for myself, I decided I'd take the one with less damage and attempt to recap it, to avoid capacitor doom.

This would be a tricky repair, as the caps are in incredibly close quarters with each other. To help lessen this issue, I went with the smallest replacements I could find. These ended up being some really cool looking red Wurth caps. Let’s begin!

Step 1: Remove the old caps. I don’t have any fancy hot air tools or methods, I just twist them off. It works fine for me, and I’ve only every broken one single pad doing it. (Which was when I was first starting).

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After removing the first one, I saw some crusty crap under it! Was it leaking? Maybe not. I never smelled any fish smell when the board was running, and there was nothing liquid. Nor was there any of the stuff inside the plastic bottom of the cap, only on the underside of it and the board. Perhaps this was there from the factory? It also left no visible corrosion. I could be wrong of course, perhaps it’s just leaked out slowly over time.

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Leakage or not, the stuff was under every single cap.

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All clean! Now to clean up the pads and remove the remaining bits of legs. (And yes, I did realize that I forgot one later on and fixed it).

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Next, let's get some caps on that board!

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I was a bit worried about installing them, as the cap legs are so small on the new ones. They ended up being pretty quick to install, but they aren’t on there very good due to their size. As long as I don’t drop the thing really hard (which would cause worse issues than some caps falling off), I should be good. It was either that or getting larger ones, which would have been near-impossible to install with my tools.

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Here they are all installed! I did go with a tantalum for the smaller one. I wish I could have used all tantalums, but they just aren’t available in such high values.

But does it still work?

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It does! I feel much better about using this system now that that tank farm has been taken care of. I've had it on for a couple of hours now, getting programs installed, and having some fun, and it's been pretty stable. Granted, it has crashed twice (Bomb errors, once when booting the first time after the recap, and another time when emptying the trash of all things), but that aside, it's been fine. I have it mounting SCSI images from my RaSCSI, and playing back MP3s like a champ.

Next time I make a mouser order I'll get caps to recap my 1400c. Like the power board, it doesn't need to be recapped, but better safe than sorry.

Extra couple of questions:
Does anyone know a source where I could get a new 5300 battery and replacement contacts for my power board? I'm guessing nothing on the battery, hopefully someone like @360alaska starts to rebuild them at some point. Compromised macs deserve love too!

Thanks,
3lectr1c.
 

desertrout

Well-known member
Nice work - I'm currently doing this on my 5300 as well but didn't think to source smaller-sized caps (the big ones are a little trickier to replace), and I did this a while ago on my 190 (not a separate board, but same idea right on the logic board). On the 190, it resolved power-on issues (boot cycling), but there was no visible leakage or anything else visibly amiss. I tested a few and they seemed fine, but there ya go. I have the same issue on the 5300, hoping this recap will fix it.

For the battery contacts, it could be tricky. I'm looking for one as well (the one in my 5300 was destroyed by corrosion), a 5-way 4mm pitch spring connector, and I'm striking out at the usual places... lots of surface mount ones out there, but no 90-degree through-hole ones that I've been able to find yet.
 

3lectr1cPPC

Well-known member
Thanks! Good luck on fixing your 5300. I remember seeing someone here had replaced the contacts on their 5300 or 190. I forget where it was and it was a while ago, but they clearly had a source, so hopefully something will turn up :)
 

k24a1

Well-known member
Okay, so now I see why my 5300 had some issues. Unfortunately I parted that laptop out a while back. :/
Great job pointing this out. It's also impressive to see just how small capacitors have been getting too.
 

desertrout

Well-known member
Thanks! Good luck on fixing your 5300. I remember seeing someone here had replaced the contacts on their 5300 or 190. I forget where it was and it was a while ago, but they clearly had a source, so hopefully something will turn up :)
Hm - hopefully we can dig that thread up... As for the 5300 on the bench... I'm optimistic, BUT the display cable is ripped so I'll have to rely on the display port until I can find (or make) a replacement flex cable. Should doable, just need the time haha...
 

k24a1

Well-known member
I'm surprised people still work on these PowerBooks despite how awful they were... lol
 

3lectr1cPPC

Well-known member
When the hinges don't self destruct they're pretty nice machines. Just don't try to put OS 9 on them though...
 

k24a1

Well-known member
I see... the screen broke on mine (I know, I'm an idiot.) and I couldn't bother to pay a fortune for a replacement.
 

3lectr1cPPC

Well-known member
I know how you feel. My left hinge broke on a 5300ce model and I foolishly closed it again with the broken hinge and it tore the display cable... It's going to be a long time before I find a new one for a price I'm willing to pay.
 

k24a1

Well-known member
To be fair, it did have some issues. A chip was burnt although the computer still worked... The battery also leaked so some minor damage was done to the power board. I never thought of recapping as I thought it didn't need it. It was a PowerBook 5300c I received from my uncle and managed to overclock to 117MHz. If I'm honest, it wasn't that good. The keyboard felt really mushy and the system felt like it was about to fall apart at any given time.
 

3lectr1cPPC

Well-known member
Strange, both of my keyboards are very stiff. It seems to get more stiff with wear, as my very worn keyboard is much stiffer than my less worn one.
 

k24a1

Well-known member
I remembered that I still have a few parts from my 5300C from when I took it apart. One of them is the power board, I might look into that. Caps do appear to be bulging too.
 

3lectr1cPPC

Well-known member
Mine did too, on both boards, but only ever so slightly. It might be normal, maybe not. Either way, both of mine worked flawlessly before recapping, so take of that what you will.
 

k24a1

Well-known member
I think it's just something to watch out for. all these old electrolytics will inevitably fail someday
 

ChrisKT71

New member
Anyone have any details on where to get new DC barrel connector jacks for the logic boards of these 5300’s? have one logic board with a power connector that fell apart. Other board has the loose solder joints.
 

PotoMac

Member
I've got a few of these. I've recapped 2 of them, just like 3lectr1cPPC did. 1 of them boots just fine, the other ticks (or probably turns on and off) repeatedly. I've tried to compare the 2 by checking continuity all over it and I can't find any differences. Any suggestions on what to check for?

Do the battery contacts need to be a certain length for it to work? Some of them are short because of corrosion on my bad one but this doesn't seem to stop my other 5300 power boards from working.
 

3lectr1cPPC

Well-known member
The battery contacts should affect anything as long as you aren't trying to run the computer off of a working battery of anything like that. Not sure what else to troubleshoot on these, I know next to nothing about electrical engineering of that sort, I just know about known failure points and how to fix them. I suck at troubleshooting. They are known to be rather unreliable though.
 
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