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Macintosh Portable resurrection (attempt) and diagnosys

ironborn65

Well-known member
Dear mates,
I had a non-backlit Mac Portable on the shelf for a year. It was given to me by a guy who sent it to a lab for recapping, but went out of business before finishing the job.
I had a complete set with a battery and charger.
The MB had no sign of leaking, very clean and nice.
The MB was without caps and some were electrolytic instead of the SMD, so I replaced them all with the proper ones (not the tantalum ones).
They removed the SWIM which was attached with a tape to the external PSU, I do not know why and if it's working, The pads were clean and not corroded.
I soldered a 44-pins socket taking care of the right orientation and I inserted the SWIM.
I did my homework and I studies the power supply system in the Apple tech manual.
I then inserted a new 6.5V 1.5A lead battery in the internal battery case, it tested 6.45V, and the external PSU was 7.5V (it was corrected after initially writing 9V).
I pressed the microswitch and I heard a croaking noise and I had a weird pattern on the LCD screen.
I decided to remove the SWIM (I'm glad I used a socket) and hurray, it played the happy chime BONG.
I don't know if the SWIM is bad (it'd explain why it was removed) or if my tiny SMD skills are not good enough.

Now I have these symptoms:
the screen remains "black", it's on, but no smiley face
the reset does work, BONG, but it stops again
the interrupt switch brings a sad mac with code 03001300 / 00001FFA, the sad mac code guide says that pressing the interrupt while in boot mode brings the sad mac, so I assume the Mac is trying to boot.

pressing both reset and the interrupt brings the sad mac
the yellow led on the scsi2sd plugged in the back does not blink, it does in my other macs when I turn them on, before actually booting the OS

now, the question is
I believe the boot sequence stops because the SWIM is not present? is it?
 
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androda

Well-known member
A 9 volt external power supply is too high. The power supply needs to be 7.5 volts at a current limited 1.5 amps maximum.

Any higher voltage or amperage is going to start cooking the power regulator mosfet because it has to burn off the extra power as heat. The Mac Portable uses a linear regulator for main 5v rail, which is implemented as discreet parts.

This is also dangerous for your lead acid battery, as 6v batteries don't like 9v as the charge voltage.
 

Johnnya101

Well-known member
Only use a correct voltage adapter. Think its what above said, 7.5V 1.5A. Anything higher will cook it.
 

LaPorta

Well-known member
Are you sure the battery will work? I once used a battery which was 6.5v, 1.5A, and it refused to boot the machine because it had too low of a peak amperage output. Switching to the Cyclon battery pack that is baiscally the original in a different package then worked fine.
 

desertrout

Well-known member
now, the question is
I believe the boot sequence stops because the SWIM is not present? is it?
Correct, the machine won't boot with the SWIM uninstalled - it'll do exactly what you describe. It seems like the SWIM you have there is bad and needs to be replaced. You can try and find a 344S1029 (likely from a donor 1xx series PowerBook), or the NMOS versions 344S0061 or 343S0061 will work (like this: https://www.ebay.com/itm/312976316394?epid=21036459825&hash=item48ded797ea:g:BfEAAOSwtPReNDr8) or you can find them on contemporary Macs, like the SE/30, LC etc.
 
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ironborn65

Well-known member
@LaPorta I'm quite positive, but at the moment the biggest concern is it could boot without the SWIM.
If the battery has not enough amperage it would shut down.
I'd expect to see the yellow light of the scsi2sd blink.

The tech manual reports:
When the computer is turned on, the system begins a
carefully synchronized sequence of events. First, the
processor is held in a wait state while a series of
circuits puts the system in a known state in preparation
for operation. During this time, the versatile interface
adapter and the SWIM chip are initialized, and the
mapping of RAM and ROM is altered temporarily in
order to test the system.

[section basics 1/27]

So, if the SWIM is not present, it can not be initiated, so the boot process stops ....
at least this is my assumption, so I better try to check all the 44 soldered pins and try again.
The other option is that the SWIM is faulty.

thanks @desertrout , I'll look for a substitute
 

ironborn65

Well-known member
I have a donor LC (or a Classic), the practical issue is if I can remove it with my hot air desolder (attached) without frying it.
I have learned to solder and desolder SMD with the hot air but this square large 44 pins IC is enormous respect the SMD capacitors.
This may be a little bit out of scope for the thread
 

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LaPorta

Well-known member
Got it. I missed the part where you said that there were actual error codes, that was my fault.

For comparison, I transplanted the SCSI chip on an SE/30 for comparison, and it worked very well. Hot air and all.
 

desertrout

Well-known member
Hot air stations are designed for this purpose. But I'd recommend hitting up YouTube to watch some demos and get some tips if you're feeling unsure. I have found that preheating the board a little and adding solder to the pins first helps move things along.
 

LaPorta

Well-known member
Also, everyone does something different, but I had good results with solder paste. You need an incredibly small amount from what you think, and any tiny bridges can be gotten rid of after with an iron. As desertroute says, videos really are your friend here.
 

moldy

Well-known member
Congrats on the somewhat working Portable, it's great to see those coming back to life! (with some resistance)
the screen remains "black", it's on, but no smiley face
the reset does work, BONG, but it stops again
the interrupt switch brings a sad mac with code 03001300 / 00001FFA, the sad mac code guide says that pressing the interrupt while in boot mode brings the sad mac, so I assume the Mac is trying to boot.
@ironborn65 what exactly was the pattern on the screen? According to my research and experience, without SWIM it should bong and end up with a clean "grey" boot screen (but without the flashing disk icon). I confirmed that on my own Portable during the repair. It should for sure not show anything weird.

I also not a single time saw a Sad mac in that case.

I have a donor LC (or a Classic), the practical issue is if I can remove it with my hot air desolder (attached) without frying it.
I have learned to solder and desolder SMD with the hot air but this square large 44 pins IC is enormous respect the SMD capacitors.
I used a similar hot air station and successfully desoldered few SWIM chips with no issues. The key is, as suggested above, to preheat the board from the bottom and top with moderate temperature (I used 150*C AFAIR) and only later hit it with the target value. I used a fair amount of flux as well.
 

desertrout

Well-known member
According to my research and experience, without SWIM it should bong and end up with a clean "grey" boot screen (but without the flashing disk icon). I confirmed that on my own Portable during the repair. It should for sure not show anything weird.

I also not a single time saw a Sad mac in that case.
During my repair, when the SWIM was removed, pressing interrupt would produce sad mac and error chime. But yes it should boot to grey screen, no 'pattern' or any other graphic.
 

ironborn65

Well-known member
thank you all guys, I'll remove a known good SWIM from an LC.
A while ago, to remove and reinstalling an AGRET I studied Youtube videos and I bought the best flux available for the job, still, I believe I fried an EGRET :(.
So now I'm concerned about frying the SWIM.
 

joshc

Well-known member
but at the moment the biggest concern is it could boot without the SWIM.
It can run without the SWIM I believe, I would do the rest of your testing without it first.

Also, I removed a SWIM chip from a Portable board with 300-320C hot air for a minute or so and it came off easily. Keep the air moving around the chip all the time and be patient. Hope that helps.
 

desertrout

Well-known member
It can run without the SWIM I believe
The VIA and SWIM are the first two stops in the startup sequence, tested and initialized first before the RAM test or any other system tests. If they're not there or functioning properly, the Portable won't boot.

So now I'm concerned about frying the SWIM.
If you're not in a hurry, you could source some low-melt solder and use that instead of hot air (like ChipQuik - https://www.amazon.com/SMD-Chip-Removal-Alloy-REMKIT/dp/B08KJKHCJK/) - it doesn't take much, it's easy to use, and it's also super helpful elsewhere like for stubborn old solder you often find in through-holes etc.
 

ironborn65

Well-known member
hi everyone,

no good news.
I checked the pins of the socked, some did not make good contact. So I removed the plastic base to better fix the solder joints.
I reinserted the original SWIM and ... silence, black screen, and no happy chime .. Geee.
So I removed a SWIM from a Mac Classic, it was not an easy task. I tried it and I got ... the same exact result. WTF

I tried with no SWIM and it chimes, so the board did not suffer any inconvenience.
Now, what do I take home?
Are both the SWIM broken? Is there something else? I restate: the MB is in very good condition.
1. the socket has still some bad joins, but I can not test them all, I'm not able to follow all the traces . I need a schematics
2. both the SWIM are faulty
3. something else is bad

Any idea?
thanks

PS: all the red-tagged pins in the pic tested ok




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