PowerBook 5300-gotchas?

[GRudolf94]

Re: 5300 vs 500 series performance complaints - one machine came with a bargain basement IDE drive kludged onto what is essentially half of its predecessor design; which is the other, natively equipped with SCSI

Laptop SCSI drives were never any marvel, but laptop IDE drives until the 00s take the prize for terrible storage.

 

[3lectr1cPPC]

I also had mine as a student (postgrad in this case). I think a common theme is developing here & if @3lectr1cPPC also had a 5300 as a student, we're several steps towards a half-brained theory on their second-hand target audience .

As one of 68kmla's few resident zoomers, I'm afraid that was not the case for me. I got mine in 2021

 

[Snial]

This one may be dumb enough that it doesn’t, but I doubt it. The BMS talks to the computer and tells it info on cell charge and such. It likely would not detect the battery without it present. It probably would run off the battery if you unplugged it while it was on, but Mac OS would just instantly put it into sleep mode. My 500 series batteries are rebuilt but the EMM BMS boards in both are not working properly, and that’s the behavior they show. The 1400 may be different, but I do doubt it.
If you just left it in there with no cells it would just report dead and the computer also wouldn’t run off of it.

Going back to this (though it may be answered in a later post). Does this mean that if someone removed the main battery from a PB5300, and powered it on, then it would just go back into sleep mode? He's finally tried it and initially that's what he saw (because the battery was corroded and therefore he's removed it). I thought the instant sleep mode was due to a PRAM setting, so I advised him to try and trick the PRAM by repowering the PowerBook a number of times (I told him to be careful as the PCB's power connection can break). Now, to quote:

"it makes a noise too, like a clucking. This is still going on but more like a clock ticking now. I'm sure it's coming from the speaker rather than the hard drive, for example"​

Now, on the PB1400 I read somewhere that this behaviour can be due to overcurrent - I saw it when I tried to use the 166MHz CPU module on the 117 Motherboard (which is the same apart from the ROMs as we now know). Is this a bad cap sign?

 

[Snial]

Update: the PB5300c has now been sent to me. The PSU appears to deliver 23.2V instead of 24V (is that an issue). The PB5300 does indeed repeatedly click on power up. On initial power-up the green LED came on briefly, but then faded over a few repeated clicks. Lots of battery terminal corrosion (really serious). I guess it could be a cap issue? If a cap had gone, then the internal supply might not be smooth, so it'd get some power, things would start to turn on; the load would lower the voltage, and then it'd turn off which would reduce load and the voltage would go up & thus the cycle would repeat?



It's worse than Crusty the clown!

 

[croissantking]

Update: the PB5300c has now been sent to me. The PSU appears to deliver 23.2V instead of 24V (is that an issue). The PB5300 does indeed repeatedly click on power up. On initial power-up the green LED came on briefly, but then faded over a few repeated clicks. Lots of battery terminal corrosion (really serious). I guess it could be a cap issue? If a cap had gone, then the internal supply might not be smooth, so it'd get some power, things would start to turn on; the load would lower the voltage, and then it'd turn off which would reduce load and the voltage would go up & thus the cycle would repeat?

View attachment 70186

It's worse than Crusty the clown!

Oh dear. I’d wager it’s the corrosion keeping things from starting. You’ll have to disassemble and inspect how bad it is.

The 23.2V on the charger shouldn’t be an issue.

 

[croissantking]

The gotcha, and what has gone wrong, is that it's a 5300.

This comment still amuses me.

Imagine the horror of all of the downsides of a 5300 series PowerBook, plus the battery vomited its guts on it.

 

[Snial]

Imagine the horror of all of the downsides of a 5300 series PowerBook, plus the battery vomited its guts on it.

I don't need to imagine now!

It's like a sci-fi horror movie... in particular it's like the sad episode of Blakes-7 where the Liberator gets eaten by some kind of extra-terrestrial fungus... or even more closely, the Protomolecule from the Expanse Season 1 converting its victims! Same colour too! It's been nice knowing you!

 

[croissantking]

You know you’re going to fix this

 

[3lectr1cPPC]

Eh, could be worse. Probably just a bad power board.
Funny how this goes. One of my power boards had contacts just as rough as yours was but it wasn't nearly as bad beyond that.

 

[joshc]

Kill it with fire.

 

[GRudolf94]

That's minty compared to the 190cs I once made the mistake of buying.

 

[3lectr1cPPC]

Building an active matrix 190cs (a 190c if you will) is something I've wanted to do for a while now. I've been surprised how few have showed up for sale, and of course, the ones that do always seem to have had the battery go thermonuclear inside, as is expected for these at this point.
The cells Apple used in the main batteries for these laptops leak worse than any other I've seen.

 

[Snial]

Update: the logic board was basically OK. A couple of pins on a RAM chip and another logic chip needed de-crudding. Also, I've carefully scraped most of the crud off the power board / regulator board (?) (though the photos show that there's still quite a bit of loose crust on the PCB and components). The square brown thing on the underside seems to be a coil and I can see quite a bit of crud on the inside. So, I think it needs to be removed, but I'm not sure how to do that since it's not through-hole. Caps seem to be OK as do all the other components and chips. Does anyone know what that coil does and whether the crud could prevent proper power to the 5300 (it might just be something to handle the battery for all I know).

 

[GRudolf94]

Both bricks on there are transformers and part of the multi-rail SMPS that is the power board. I would try finding a way to bench-test this - a failure could well cook the machine. One open via is enough. Ideally you'd remove those with hot air. Even more ideally, you'd find a replacement power board that hasn't been bombed :/

It's the kind of thing that designing a replacement for is well within the realm of possibilities, just I don't think many people with a 5300 able to do it would care to put in the effort.