Notice to Powerbook Duo Users!

This requires taking the screen itself apart right?

Don't think so, I think he's talking about what looks like a small tank farm under the metal hump near the AC adapter lug on the Mobo, opposite the Modem Bay hump.

Precisely. But you do have to take the surrounding metal frame off to see/get to them, and that involves disassembling the entire thing (except screen).

I would rather warn everyone now, before it gets too late.

In case anyone wonders, they are 4 100uf 35v, and 2 100uf 25v. Something that every tech should have in a junk drawer. But there is a small clearance area, so low profile Nichicon caps are a must if you go radial. (luckily, i have a bag full of 25v. no 35v though. booo).

plus the 33uf 25v thats out there by itself.

Thanks for the warning. Yet another reason to stop stalling and recap my old PBs.

yea exactly. Not trying to be an alarmist or anything, but we cherish these older things, and if you say, blow a transformer, or a now discontinued SMPS switching IC on a portable logic board, How are we going to fix it? we arnt. Its going to be up to the engineers (like myself) to find a work-around to the damage in the power supply.

Anyway, When i disassembled this unit, i happened to notice it, like uh-oh... here we go... Its hard to say the conditions the Duo was in before I got it. its basically scrap now, but it does have a good logic board and stuff. Going to pull and save the inverter for another person that has a bad one.

So i cannot say if your caps are bad or good, but seeing what I saw, change them anyway.

Also, the 35V caps appear to be the 24v DC input filter. the other 2 appear to be the DC-DC filters.

Ok this seems like a silly question, is there a specific way of storing these or other boards until they are fixed? I'm not talking about temperature or humidity. If the boards were upside down, would the fluid just leak on the cap? Can gravity even make a difference on such a small object?

You know, those are questions that i cannot answer as I have no idea. lol.

you would figure if the logic board is upside down, it would leak on itself, but then again, the only place those will leak from is the bottom.

I'm pretty sure my 280c died this way, I recall hearing a ticking sound coming from that area..and that's all it ever did again xx( . I have very little soldering skills, I wonder how much one would charge if I brought the board in for cap replacements somewhere.

Ticking sound was from the DC-DC circuit. if it quit ticking and is dead, thats BAAAD news :-(

I just stripped down a powerbook duo 270c which has a busted screen. I have noticed that the few electrolytic SMD caps this board has, are starting to leak, leave signs

Click to expand...

Recapping the logic board is an easy job. The radial SMD capacitors in the LCD panel are another issue. Have a look behind the foil that covers the back of the LCD panel of a Duo 280c. The LCD panel is full of small radial SMD capacitors, some of them are already leaking or have high ESR readings.

Yep, the first thing that comes to mind would be to store them upside down.

Second thought would be take the MoBos out and place them upside down on an absorbant material inside a zip-lock bags for any mothballed mac.

Same thing x2 for Analog Boards.

Just storing Macs 0r PBs upside down and Compacts on their sides ought to help and probably can't hurt. What's the viscosity of the leakage? Will it well up and harden on the top of the cap stalactitically or drip? Anything has to be better than having goo spreading to additional traces.

Apparently I've been storing a couple of dozen various types of bare MoBos in the wrong orientation. :-/

Spreading goo on the silver sides of caps ought to be easier to spot than same on the MoBo when inspecting for re-installation or a pre-power-up inspection of a mac stored inverted.

Id rather just replace them and be done with it. period. But thats my philosophy.

Ya the caps on the LCD are another issue, but i covered that back on my PB 1XX models. I just used the same style SMD replacements because clearances are too small.

For the record, the ESR on SMD lytics wernt anything to write home about anyway.. thats why engineers use multitudes of them for one general circuit instead of 1 large one.

Some of us have too little (or none at all : ) experience in re-capping and much larger collections than would be likely to be recapped before one of the uncapped mobos springs a crap-out-n-kaput cap leak.

Eh. might have to join in on the recapping service i guess

Ok this seems like a silly question, is there a specific way of storing these or other boards until they are fixed? I'm not talking about temperature or humidity

Click to expand...

To avoid damage to the board, I take a photo of the board, remove all the capacitors and then clean it.

This way the board can be stored as long as want until you have time to replace the capacitors.

Have we got the "Definitive Guide" to re-capping developed here yet?

Start with the listing for every MotherBoard's Caps/Ratings/PackageType etc. and the Silk Screen Layer's designation for them.

After that we can add pics of each board with arrows pointing to the locations with the listing table for a single page printout . . .

I can do some of the graphics, it'd be a cool project for collaboration between our boffins, photobugs and graphics oriented comrades all over the world.

Maybe start with the MoBos trag has kits available for at great prices and then move on to parts listings/replacements from some online sources at reasonable pricing/policies for small quantities across the face of the planet.

I don't do Flash, but links to short videos of all the different replacement techniques for each Cap type would be great content as well.

I dont know, but I know mk.558 was starting on that by doing the SE/30 pic.

FYI, here's the "tank farm" that is spoken of:



Duo 230 (68030) foreground, 2300 background (PPC 603e). Also FYI, the 230 display connection will not hookup to the 2300 motherboard without some sort of adaptor. The 2300 display port is closer to the back of the unit (ie, away from an imaginary user) and is larger. Since the 2300 board was offered as an upgrade option, I imagine there was an adaptor ribbon of some kind. You can see the 2300 display connector in the hole to the modem-side of the CPU, the whitish vertical up pointed port. The 230's is right behind the large chip just to the modem-card-side of the CPU, and is a black connector that is perpendicular to the general orientation of the board (as where it is now, it's right near the reset button on the 2300's board.)

EDIT: I'm thinking I might do a write up on the Duo boards. They might be all identical, I mean there's just the 68030, 68040, 68LC40, and 603e, there can't be that much difference in the capacitors we are after. They do look big, juicy and could let off quite a BANG if they wanted to.

EDIT 2: I have the 230 board right in front of me here, there are:

2x 100µF 25V

1x 330µF 16V

3x 100µF 35V

1x "W1 33 25V" with a line over the W. Probably 33µF at 25V.

Not too bad. Soldering in the proper order (ie this one first, then this one, then that one) is probably advised, lest you box yourself in :-x As for the 2300 and the others, well, I'd have to ask our fellow soldiers for that, since I don't have a 210, 250, 270 or 280. As for my 2300, well, I'd have to take my 2300TB apart all over again, removing the CPU stiffener isn't exactly fun...but not as bad as the iBook G3 600MHz on up...

For anyone paranoid: be very paranoid.

This same thing is happening on video game hardware too left and right. I had to recap a Nintendo as the caps for sound went out and I had to max out my amp just to get it to normal levels. Game Gears are dying left and right because of caps as well as Turbo Expresses, Super Nintendos, etc. Only a matter of time before caps die (obviously a bit hard for ceramic disc to do much) and at worst they will take nearby traces with them.

The good news is that often times you can find physically smaller capacitors as replacements than what was originally used in Apple hardware.

If I did a Duo recap guide, I'd have get the schematics. I sifted through the Apple Service CDs I have and I didn't see any schematics, and I doubted there would be. Most just service manuals, MacTest Pro, random this and that and so forth.

Well, I wouldn't have to get the schematics, but I'd have to know what the + and - pins go to. That's kinda hard, because it's not well-known how many layers the board is, and the components are smaller than the SE/30 or a Mac II board, which is comparatively spacious, if not luxurious

That said, I'll do my 2300, but I first have to worry about some other things for it (battery recell, PRAM battery, CF adaptor, display housing, and more RAM).

When I get some spare time, I can help out with the capacitor pin connections.

CAPTAIN! CAPTAIN!

What is it soldier!?

MORE ENEMIES!!!



What and who is the culprit?

A DUO 2300! The 230 returns clean!

Good job soldier! A+ to whoever broke the plastic retainer thingys, you can see them near the hinges, the female end has been broken off the display back. (If you have have a proper replacement, hit me up)

Can u haz got MiniDock?



Two 35v 100uF caps with a pair of 16v 330uF tanks await you!

I dont own a minidock.

I own a DuoDock. last I used it, it worked. But its missing the floppy drive and assembly/cable/bracketry.

Hopped down to the electronics store.

Got most of what I needed, sort of: it appears that the tank farm is spec'd out to 105 deg C caps.

Got 4x 100uF 35V caps, 1x 100uF 25v, and one 35v 47uF. Good news: the replacements are smaller than the originals at the same rating.

But I don't know what "33 EHA 5B7", "50v 2.2", "g2 10 50v", "5S 68 10v", or "e3 47 6v" are. The voltages are obvious, the capacitance is not.

Yea they are, they are in plain english.

"33 EHA 5B7", "50v 2.2", "g2 10 50v", "5S 68 10v", or "e3 47 6v"

33uF 2.2uF 10uF 68uF 47uF

So those random characters are manufacturer codes?

What is the voltage for the "33 EHA 5B7"?

I would assume so, on the manufacturing codes.

must be another number on that cap somewhere, as voltage isnt listed.

you can easily figure out what the voltage is depending on where it is in the circuit. It might even be non-polar?

Nah there's a tiny + sign near the area relevant to it. There are two of them on the motherboard. C41 and C94.



Higher resolution.

That board is like the Milky Way of Vias.

I'm banking on 16v. No idea, though. Or 10v.

Well thats a good one actually.

It could be 33uf at 5.6v.

But it could also be 0.33uf at 57V. But i dont think so. I am betting on 33uf at 5.7V

Grab a meter and measure the DC at that cap during operation, thats how we will know for sure.

Checked with a voltmeter with the power on. A steady 4.96 to 4.97 volts. Bam.

This means it's probably a 6v unit. I'll probably go with a 10v to be safe? I mean the thing was in pieces, the display was connected and on, trackball, a SCSI HDD, UltraDock, external FDD, no modem card, and a paltry 4MB RAM card.

From the very limited accurate information online, "5B7" refers to a case size. Which is about right since it's about 6mm x 7mm...ish. The actual voltage rating can be 4V to up to 63V. source

Since it says "33 EHA 5B7", 33 probably refers to ...I dunno, there's a possible match at 10v 33uF with a 5B7 case size. I don't care about the case size because of what I'm replacing all my caps with (electrolytic), I care about the capacity and voltage.

Well with the measurements you gave me, that cap is part of the 5V rail. So a 6.3v cap or a 10v cap would be fine.

But if it were me, i would get a 33uf at 16v.

I own a DuoDock. last I used it, it worked. But its missing the floppy drive and assembly/cable/bracketry.

Click to expand...

Have you taken a look inside the PSU. It's recapping time there as well.

Well with the measurements you gave me, that cap is part of the 5V rail. So a 6.3v cap or a 10v cap would be fine. But if it were me, i would get a 33uf at 16v.

Click to expand...

I replaced them with 33uf, 25v: given the power supply is at 24 volts, you're 100% sure it works.

I have recapped all my Duo's a while ago and use them regularly without problems. Always use a higher voltage when you're not sure.

Not exactly. Maybe in this case, but not all cases. power supply may be 24v, but there could be a 40v boost in there somewhere to feed passive panels. Now sometimes this voltage is built into a DC-DC circuit on the panel.

So dont take that for granted ;-) My previous point stands that it depends on the circuit.

At what point would too much voltage rating effect the caps intended properties?

probably never. if your running a 50v cap in a 2v circuit, it isnt going to make a difference i dont think.

Now, running a 2v cap in a 50v circuit, well, you would have to try it.

I've got both a Duo Dock and a mini Dock. Shame my Powerbook is stuck in the Duo Dock and I don't have the key.

I'll just have to find me a pick gun and have at it I guess.

The notice on leaking caps on the display PCB of PB Duos reminds me to the problem of moribund TFT panels in some PB 180 machines. Did someone investigate if the display malfunction might be caused just by a capacitor leakage and therefore could be fixed?

I've got both a Duo Dock and a mini Dock. Shame my Powerbook is stuck in the Duo Dock and I don't have the key.
I'll just have to find me a pick gun and have at it I guess.

Click to expand...

Use a Dremel and cut the Dock open?

Yes the Minidock also need recapping. So does the PSU of the large Duodock...

Well...

The recap job on both of the boards went smoothly. No hitches or hiccups on the way. I was pleased.

The End!

That...is what I was hoping for. Ughm...gonna need some tantalums. Not enough room on the display inverter board. PACKED in the display board, up the left side. Oops. We'll be okay. Definitely didn't see the 47uF 6v cap (I used 25v) near the top left corner of the keyboard coming. Can't put the keyboard down. Actually went not tooooo bad...bit of a problem removing the old tanks because of the tight proximity to each other. tsk tsk tsk

Pictures...maybe tomorrow. "How many pads did you lift?" Uhmm...ugh...a few

Thanks for the info about problematic caps. I've got a Duo 280c that needs inspection for this problem. The full Dock had the clicking problem a long time ago, but I never replaced the PSU caps. I did not think it was an operation I could handle myself. More recently, I recapped the PSU in my TiVo DVR, and that was rather easy. The Powerbook disassembly is a bit more intimidating, but I can handle it if I can find a clean surface to work on.

Can someone tell me if these issues are symptoms of the bad caps? The Duo runs fine when the battery is inserted and the power supply is connected, but the battery is not recognized. I used to be able to trick the Duo into seeing and charging the battery if I removed it for a few seconds and then reinserting it. That doesn't work anymore. If I remove the battery, the Duo will turn off after a few seconds. The Duo will not turn on unless both the PS and battery are connected. Resetting the Power Manager does not help.

 

Also on the capacitor agenda is a couple of my Quadra 840av motherboards. Hopefully they haven't damaged the MB yet.

I feel like a complete dufus. It's been a while since I've posted anything on bulletin boards, and now I've managed to do it wrong. I messed up the italics BBCode in my previous post and now phpBB won't let me edit the post to make the correction. Very frustrating. I must be missing something obvious. Is it because the thread is a Sticky?