The Elusive PowerBook 550c

[freudling]

Oh PowerBook 550c, where art thou? Nobody even discusses you on this forum...

Anyone remember the coveted PowerBook 550c? It is "the" most rare PowerBook of any, only released in very, very small numbers in Japan.

It ran a full 68040 processor with integrated FPU, whereas all other 500 series PowerBooks ran the stripped down 68LC040 processor. Screen size increased to 10.4" from 9.5" and it offered 16 bit color like the 540c. It also came in an all black case!

Comments...

Spicture:

 

[bluekatt]

possibly nobody discuses one because nobody has one ?

id like to discuss the powerbook 2400 240 mhz version but ima but hard pushed to get it

 

[blackbird]

Does anybody in this forum own one? I've been looking for one for years...and nothing.

 

[freudling]

Ya, me too. Years back you would see the odd one on Ebay, like twice a year, now, nothing. I check all the time.

 

[wthww]

Not to spill the beans or anything on him, but our very own defor has one, previously owned by IPNixon. Its very nice, if not in decent shape. Never the less, please remember that it sadly shares the vulnerability that all powerbook 5xx machines share. Bad hinge design and poor plastic formula :'(

//wthww

 

[Byrd]

Bad hinge design and poor plastic formula

I've never come across bad hinges in 5x0 'books, but certainly have found huge variations in plastic moulding quality across the board. Most 5x0s have really brittle, thin plastic that scratches and snaps very easily, but I've come across one or two that had notably better quality mouldings. Of course, when taking apart your 5x0 be careful with the lower screen "Apple" bezel that almost always snaps tabs no matter how gently you remove it.

I'd love a 550c - it is the ultimate 68K Powerbook by a mile.

JB

 

[defor]

I have a 550, and a number of 520/540 variant, including the from-factory 500 PPC

My 2¢ about the brittle plastics:

I first came across this problem when I was getting back into collecting old macs about 3 years or so ago with a number of the Duo series.

The problem you,I, others, and eventually everyone is facing, or will eventually face, is that in order to crete the dark grey and black plastics found in classic PowerBooks, a dye was added to the ABS plastic that reduces it's overall sturdniess-

Well, when the systems were new, this wasn't an issue...

But, the same process that yellows the plastics in "beige"/"platinum" systems under exposure to UV light, also weakens the internal bonds, making them more fragile. This coupled with the Black dye, makes for a VERY weak substance!

I've had the hinge problem you speak of on numerous Duos,5XX's (yes, including the 550), 2 MacTV's, 5300's, and countless accessories.

Thankfully, MOST of the effects of UV weakening are ignorable if your system doesn't experience havy bumbs, or has a decent internal frame, but duos, 5xx, and 190/5300 ALL have a hinge design that relies on the back and frnt lcd housing being sturdy and resiliant.

As an addendum- while a quick reaction might be "oh, that peroxide/oxy bath combination will reverse the UV light's effects"...

DO NOT use this on black plastic that is already experiencing cracking!

While this process does reverse the visible effects of UV light, it does so by removing the bromine, and in the process, actually weakening the bonds of the ABS very slightly! (on desktops and other "tough" systems, it's not a huge problem, but laptop plastics are thinner, and already at the failing point!

In conclusion- there's 2 options for solving this problem:

1) epoxy or other bonding agent that can create a new UV-resistant bond to the screw posts and reinforce the cracking surfaces.

2) service parts (stored in darkness and away from heat) or remanufactured parts (yes, there are a few aftermarket lids, etc that were made in japan for the duos and 5xx) - there's also nothign to stop someone from makign their own aftermarket duplicates really- there is a known problem as you do see...

In the end- if you use your powerbook, or expose it to any uv light- your powerbook will eventually also have this problem!

A general word of warning, and a note to those saying "oh my powerbook is better because it doesn't have any cracking"- in time, and with use, IT WILL.

 

[defor]

I probably should have read the thread rather than replying about weak plastics as I was asked to

anyway- yeah- the bad hinge design is less of a "bad hinge" design and more of a "metal hinges connect to plastic (lack of) frame"

the main design flaw is that apple designed the LCD assembly to depend upon the rigidity of the back and front being held in fixed relation to each other due to the upper lcd screws such that the 2 of the lower screws that go from front to back sandwiching the hinge plate do not get trapezoidal flex.

this is fine and dandy, but the eventual breakdown of grey abs (moreso in the black plastic of the 550), removes the slight springiness that it has, so when the screw posts are flexed, the mount wall surrounding them slowly tears apart.

Once this has happened, the lcd still opens and closes, but it feels weak. at this point, the hinge is relying on ONLY the secondary screw posts which attach to the bacl cover only. this mount point has no bracing or support from the front cover, and as such, will eventually rip through as well, with usually more disastrous results.

preventative measures would be attackign the back assembly and hinge plates with some metal filled epoxy and ereinforcing the outer ring that holds the screw posts, or more drastically, affixing the entirety of the hinge plate to the back lcd. while the second solution is FAR more damaging if you are going for "cllector" value, if done right, the hinges will fail at their base before the lcd panel ever takes damage due to the massive surface area potential of the hinge plates.

 

[gobabushka]

good luck finding one man!

 

[NeverGoBack88]

Does anybody in this forum own one? I've been looking for one for years...and nothing.

Good Morning,

On a tip from an eBay user regarding this forum, I come looking for advice, and just registered earlier. After roaming around for awhile, (Wow, impressive!), it looks I've come to the right place. In a way, I hesitate to jump into this sea of desire for a 550c, but from the posts I've read already, especially re: 500-series PowerBooks, there's some serious knowledge here.

Last Fall I lucked into a 550c (the last hole in my end-of-iteration interests) on eBay. It arrived working just fine, in beautiful condition, although only on AC power (original batteries long-dead as expected) and continued to do so for weeks. While doing minor topical dusting & detailing, and with the AC adapter not attached, I removed both batteries from the bays to check for dust, but after replacing them it would not start up from AC power, - voilá!, just like that. I had been through a similar problem (thinking it had been a lost intelligent battery link with the CPU) with a Wallstreet and an original G3 iBook, although those were semi-active machines at the time and certainly a deep-discharge battery state was the likely origin in both) and solved them both by simply replacing the main battery with a new one. At the time that was an easier proposition than these early (first gen?) M1906 intelligent batteries are now, although I've had some batteries rebuilt. Like my PowerBook 170 with it's long-dead internal clock battery but still working like the day it was made, I don't think that the internal clock battery is part of the problem, unlike how it proved to be the solution for the early G3 iMacs. In both cases, a major access hassle. I have not tested the, nor tried another known-working, AC adapter. I did note advice here in the 68k PowerBook area on that likely culprit. Have seen many available, some known working, others untested as always, but have simply not taken the leap to spend the dough to try that route.

Any thoughts would be much appreciated.

kind regards,

 

[beachycove]

Have you tried resetting the Power Manager?

From the Service Manual:

Reset the power manager if:

• The battery and power adapter are proven good, but the

computer will not power on.

• The computer will not reset after a system crash.

To reset the power manager in the PowerBook 500 Series,

1 Remove the AC adapter and the battery.

2 Let the unit sit without power hooked up for 3–5

minutes.

3 Simultaneously hold down the Control, Command, Option,

and Power On keys for 5–10 seconds.

4 Reinstall the battery and, if necessary, reconnect the AC

adapter.

5 Turn on the computer.

 

[NeverGoBack88]

Hi beachycove,

Thanks for your good advice. Yes, sorry I neglected to mention it, - that was one of the very first things I tried, multiple times, to no avail. With all these vintage Macs hanging around, you can bet I have several editions of troubleshooting guide books on the shelves as well, Ted Landau's "Sad Macs..." editions especially, have proven to be invaluable over the years, as well as those CD-R compilations of service manual/take-apart guides that are available out there. The funny thing always is that, for the most part, any problem can be fixed unless there's a critical part that just cannot be found any longer. And the whole 500-series has its share of well-documented problems, mostly physical-staying-together (or not!) issues, many of which I've seen on other people's 520/540's. Sad. I guess I should really bite the bullet and get another known-working AC power adapter in order to rule that out. It's so sad to have the premier vintage Mac of my little group "off the reservation" so to speak.

kind regards,

 

[beachycove]

I have a 540c that is very, very picky about how the power supply is connected. I thought for the longest time that either it or the power brick was dead, before I realized what was wrong. Like your 550c (and we are all green with envy), my 540c worked first time and then did not.

I took it apart, expecting that some re-soldering was needed. There was absolutely nothing wrong with the soldering in the area of the power connector in the machine; in fact, it would be hard to do damage to this in a 540c, so robust is the design in this respect. What I discovered was that the little round plug on the power supply itself had an issue whereby metal connectors (female) underneath the plastics had come loose, so that an electrical connection with the (male) wires in the receptacle on the PowerBook itself was difficult to establish. There is more to be said about this, relating to the plastics on the plug - for which, search further in these posts - but to cut the story short, once I figured out the way to establish a connection, the problem being literally within the little round plug, the machine has worked just fine 100% of the time.

I would initially try some wiggling, seating and reseating of the power connector while holding down the power-on key. Maybe a knock of the plug down on a table would help matters along, as the female receptacles are basically semi-circular, elongated 'pipes' meant to receive the wires that you see protruding from the machine in the power connector area. You want them right up against the holes in the plastic centre that you can see in the power connector area.

I don't quite know how to put this better, but once you take a look, you'll figure it out.

 

[Byrd]

If all else fails, I'm betting a stock standard PB 5x0 motherboard would be a straight swap, just switch over the processor card. Care to post some pics of your lovely 550c?

JB

 

[NeverGoBack88]

Hello again beachycove,

Thanks for this great advice, it all makes very good sense, and deserves an investigation so I will check it out. I haven't ever owned any of the other 500-series,- only seen friend's machines falling apart mostly from the plastics maladies described in other posts here, so this aspect is new to me. I'm sure there must be a great reason to have made a more complicated power connector on these, - compared, say, to the simplicity of the early 100-series. Although that begs the question as to why did they ever switch from metal catches on the screen lids to plastic ones as on the 3400c. Stooopid.

And greetings JB,

I appreciate your advice too. For me, unlike a lot of you (someone's posted photo of their very active workbench comes to mind, been trying to find it again in the posts... ) I am not a skilled tinkerer/technician in this early era of Mac laptops. I am an electrical technician in other disciplines and mechanically inclined, and so was brave (and successful) enough to crack open my 3400c to swap the RAM in order to max it out to 144mb, - and that seemed risky enough for me. With an otherwise intact 550c, your suggestion would be (to me) like scraping some gold off the holy grail just to see if it's plated or solid. I've had a lot of desktop Macs open for a wide variety of reasons and never screwed anything up, but until the G3 PowerBooks came out (I have a Pismo) with their easy access, the whole scenario of dealing with delicate electronics in very cramped spaces was too daunting, and this is not the machine for me to practice on. As for photos, I do have some and be glad to; what's the right procedure for posting them on this forum? Suggested size limit etc...

Thanks!

 

[NeverGoBack88]

Hi again beachycove,

Just gave a try with your suggestion about the power adapter plug at the Mac's end, - to no avail. While roaming around yesterday before registering on this forum, I did note discussions about the male pins on the Mac's rear port getting easily bent, and fortunately that is not the case, all are intact and straight. However, it wasn't until today that I noticed that one of the four holes in the adapter plug (lower left as you face it upright, alignment slots in 6 o'clock position) does not have an internal sleeve (pipe). The other three are quite obvious and come nearly to the face of the black plastic casing as you suggest and as I would expect. Is this normal? Does the connector use only three of the four pins? I am accustomed to other industries (audio & electrical) where stock multi-pin connectors are used off the shelf but custom wiring applications do not require all pins to be used in manufacture. Leaving out a sleeve would accomplish this but I also thought it might be conceivable that the sleeve might have come loose and fallen out, or gotten stuck on the adapter plug's pin (not the case), during my short time with it. It would be very easy to miss!

Not having easy access to another matching AC adapter, I looked at what came up on eBay with a search for M1893, and of the 7 results (most untested/unknown working, as usual) three or four had pretty darn good closeup photos of the connector face. They all showed the same thing: a black unlined (no sleeve) hole in that lower left position. So unless loss of it is a very common scenario it would appear that this is normal. It is easy to see with a flashlight that all four pin holes have metal at the depth of the hole, and with one sleeve missing to defeat that position for comparison, I think I understand 110% the details you were explaining in your previous reply about the "pipes" that I am referring to as "sleeves". I would really hope they are not supposed to move in or out, maybe just "pressure fit" in there though, which might allow for movement with age/shrinkage, but who knows.

Very good to hear the internal connection on the board is a solid one, you are indeed right that these early models were built like tanks, I've always said so. I went from a PowerBook 170 to a G3 Pismo (both purchased new), - imagine my shock at the obvious difference, then to my current everyday 12" G4 PowerBook. Holy crap! You can't be gentle enough. My biggest concern is dealing with the power cable attachment to the port. When I got our daughter a used end-of-the-line (all the great features) 14" G4 iBook last Fall, my resounding advice is a hyper-awareness of that connection. "Hey, it's not a joystick!" Always straightly aligned, using gentle pressures, and always aware of the cord and not getting it yanked on.

If anything changes I'll keep you posted. Thanks again!

 

[beachycove]

There are only three connections to be made. The other is a dummy.

 

[NeverGoBack88]

Thank you! I was hoping that was the case... still, it no workee...

Does anyone think the AC adapter may have (very) coincidentally decided to give up the ghost? I experienced that with the external power supply to the G4 Cube I had started my parents off with several years ago. Purchased new, it worked fine daily for a few years just sitting in one place. When I went to replace the Cube's clock battery, and had unplugged the power supply, after putting it all back together the power supply had simply decided it was time to retire. Luckily it was still easy to replace with a new one.

Also wondering about other components, capacitors on the board etc; if with age and long periods of non-use, the shock of getting powered up drives certain things over the edge. One of the topics somewhere here seemed to speak to that. I've had that happen with Color Classics especially, been in storage for years, power right up and work fine for a while, then gone without a trace, - and the symptom is always the same as is true with this 550c: absolutely no response when pressing the power up key.

Ah, the crap shoot of vintage electronics... sometimes I think the only reason all of my old Macs still continue to work fine is that they get used on a regular basis, but not too much, and never sit idle for too long.

Thanks.

 

[beachycove]

I am about out of ideas, and am not the best equipped of 68kmla members to answer these questions. However, some random thoughts:

1. A multimeter would offer a ready means of confirming the working condition of the PS.

2. It occurs to me, though, before you go to such further trouble, that some powerbooks with a dead battery will not start with the dead battery inserted, or at least, they will not do so when they are giving problems. I am not sure why, but I have found that this has been the case with a number of different models.

3. It could be that you have the 5xx-series equivalent of GLOD on other older PowerBooks. The 550c's behaviour here would not be well documented, or not documented in English at any rate, though it would presumably be akin to that of the 5xx series in general. GLOD is, of course, generically a problem related to the backup battery and to the power management system in the machine.

4. I can also tell the tale of getting a 540c given to me some years ago that I later gave away again, and that finally came back to me as and in parts. It first came to me from a local chap who is really very knowledgeable, but who could not for the life of him make the machine boot. I got it home and promptly took it apart, piece by piece, in hopes that reseating everything might make it work. I reassembled and was delighted to find that it started up first time after reassembly and subsequently never skipped a beat — until being physically mangled by the developmentally delayed young man I in turn gave it to. What was left I eventually got back in pieces in a plastic bag....

Apart from that, I don't know what to tell you, apart from something like, "Sure, you just send that old 550c on to me!"