Macintosh Portable horror story

[wottle]

So I recently picked up a Macintosh Portable from a guy who found it in a home he was flipping. Unfortunately, no power adapter, and the cover over the floppy and hard drive area was missing. It was also a 5120, meaning no back light. When I got it home, I started disassembly with high hopes, because the machine was actually in very good shape, just a bit dirty.

When I got inside the drive bay compartment, I was less excited. I could see what looked to be the cut ends of the hard drive cable. Disappointing, of course, but then I saw the cut end of the display ribbon cable. I did also find a leaky 9v battery, but I think I got it out before it corroded anything around the main battery.

I know there was a thread here for replacement ribbon cables, but it looks like that was for the backlit model. Not sure how different the cables are. Unsuccessfully searching for a new cable, I became worried I wouldn't be able to get this machine working again.

But then after disassembly, I noticed this odd card in the middle. Originally I figured it was a video card, but I set it aside as I addressed what I thought was a more pressing concern, looking for leaky caps on the boards (surprisingly, they are pretty good, but will be removing and recapping at some point soon). Upon closer look, it seems to be some sort of backlit upgrade board.

It's an Apple board, so I guess Apple offered an 1st party backlight upgrade for 5120 models? Unfortunately, the display cable looks to be some sort of special version with a pigtailed connector that goes to the backlit upgrade board. I'm guessing that makes it even less likely that I'll find a functional cable?

Anyway, any advice on how to proceed would be appreciated. Anyone out there with the skill to put a patch cable in between the ribbon cable's cut ends?

 

[pocketscience]

Wow! Never seen that before! Can you take some more photos, including the reverse side of the board?

There's a 5120 display on eBay right now...

 

[wottle]

Wow! Never seen that before! Can you take some more photos, including the reverse side of the board?

There's a 5120 display on eBay right now...

Yeah, I actually found one that appears to have had the upgrade installed: https://www.ebay.com/itm/266119310096

I also took apart the LCD assembly to see if it essentially is a M5126 LCD and assembly bolted on with an adapter board and new cable harness. I've never seen a 5126, so I'm not sure, but I'm guessing it was. Here are some photos of the contents of the LCD assembly and the upgrade board.

 

[wottle]

Also, @Androda , if you make any more of your Mac Portable BlueSCSI adapter kits, my cut portable could use one! . I'll pick up one of your Portable RAM upgrades while I'm there. Two sales in one!

 

[pocketscience]

Nice one! Thanks for the pics!

 

[Androda]

Also, @Androda , if you make any more of your Mac Portable BlueSCSI adapter kits, my cut portable could use one! . I'll pick up one of your Portable RAM upgrades while I'm there. Two sales in one!

Yes, I'll put together some more of those.

What you have is the official backlit screen upgrade for the original portable. And lucky for you, I also recreated this screen flex cable. It's just not listed on my site because these are so rare. Pretty sure I have at least one more of these cables.

 

[wottle]

Yes, I'll put together some more of those.

What you have is the official backlit screen upgrade for the original portable. And lucky for you, I also recreated this screen flex cable. It's just not listed on my site because these are so rare. Pretty sure I have at least one more of these cables.

Yes. Let me know when they're available. I think I'd do the service where you transfer the ends. However, it looks like my end is different than the one you produced, is it not?

 

[Androda]

Yes. Let me know when they're available. I think I'd do the service where you transfer the ends. However, it looks like my end is different than the one you produced, is it not?

Doesn't look different to me. As I said, I also recreated *this specific* screen cable.

 

[wottle]

Doesn't look different to me. As I said, I also recreated *this specific* screen cable.

Ah, I thought you were referring to your M5126 Flex cables. Didn't realize you had done one for the upgrade! That is so awesome!

 

[wottle]

So, I have a flex cable replacement ordered from @Androda (along with a replacement hybrid board, RAM upgrade, and BlueSCSI adapter and cable). The should address the cut cables. I did a recap, and found some broken traces thanks to @Androda's fantastic guid on checking resistances around the hybrid board here. I have a charged 6v battery that I'm going to swap in as a replacement, and wanted to see if this board will even boot (there was so much brown liquid (not sure if it was from caps, or a spill, or something else) that all the pins on the left side of the board had a tint to them, I tried scrubbing with isopropyl alcohol and a cotton swab, and more just kept coming from under the chips. So, I did a full soak and scrub, and a rinse in distilled water at the end. The board looked fantastic heading into installing the new caps. With the repaired traces identified earlier, I think the board seemed in good enough shape for a test.

I hooked up the battery, the speaker, and the keyboard as a minimal test, and hit the space key. And I got the boot chime! So, I'm pretty excited about that.

If I can get this machine up and running, I'll be very happy - I've always wanted one but have never used one. Once Androda gets my cable so he can move over the connector, and I get my replacement parts, I'll update everyone on the end result. Thanks again, all, for the help!

 

[wottle]

While I wait for the remainder of the parts to arrive, anyone happen to have a drive case cover? It's the piece that covers the hard drive and floppy drive on the right side of the machine. Mine was missing and I'd love to have this be a complete machine when (if? no definitely when) I get this machine running.

 

[Sideburn]

Yes, I'll put together some more of those.

What you have is the official backlit screen upgrade for the original portable. And lucky for you, I also recreated this screen flex cable. It's just not listed on my site because these are so rare. Pretty sure I have at least one more of these cables.

Ahh! Good to hear I’m in line for a BlueSCSI portable adapter and a BlueSCSI V2 to get my portable back up and running without the need for an external drive. Just put your RAM upgrade in it today and it’s perfecto!

 

[Sideburn]

Btw the portable I just repaired (new caps, new hybrid, new battery) aside from the seemingly dead Conner drive, I have a single pixel line running across the lcd screen. Is there a way to upgrade the whole display to a backlit version aside from trying g to find one of these ultra rare apple backlit upgrades?

 

[Androda]

Btw the portable I just repaired (new caps, new hybrid, new battery) aside from the seemingly dead Conner drive, I have a single pixel line running across the lcd screen. Is there a way to upgrade the whole display to a backlit version aside from trying g to find one of these ultra rare apple backlit upgrades?

There's almost always a way, if you're willing to do the work and build it out yourself.

 

[Sideburn]

There's almost always a way, if you're willing to do the work and build it out yourself.

I think I’m willing. I just haven’t found the way yet. I’ve done it before to other LCD panels with that EL sheet stuff.

 

[wottle]

I received the components from @Androda yesterday, as well as my Mac Portable battery adapter PCBs and spent some time last nights getting my Portable back together. Installed the new flex cable, added the BlueSCSI adapter and fresh Portable SCSI cable, and reattached the display. My first test was a bit concerning because using a BlueSCSI I had laying around, I got a picture on screen, but no backlight. However, it was an A/UX image I use with my SE/30, and I believe the blacklight control may not be on by default, and having the appropriate software installed could be the issue.

So I created a new BlueSCSI image with DickJockey, installed 7.1 on it with Mac Portable support in Basilisk II. Fired the Portable back up and after a bit longer of a delay (I also added the 7MB memory upgrade card I received), the picture came up and the backlight was on!

So excited to have this machine up and running as I had assumed when I saw the flex cable destroyed I would need to find a donor machine to have a change at making it functional. Really have to give many thanks to @Androda for the work he did to recreate the flex cable, even for such a rare thing as the backlight upgrade module! His work was excellent - he moved the connectors over for me as I didn't want to risk damage to the fragile flex cable, and he has many other commonly needed replacements. I was worried my hybrid module might be bad due to the damage to traces around it, but after fixing the traces, my hybrid module appears to be ok, but I ordered one and now have it if I run into issues down the road.

So, now that I have a booting machine, I have a few remaining issues.

1. I don't have a hard drive / floppy cover for the right side of the machine.
2. The trackball is nearly unusable. The rubber rollers that the trackball should roll on are no longer round, and do not allow for the cursor to move. Left/right is doable, but inconsistent, but the up/down roller has a lump in it so big that it refuses to make a full rotation, making it unusable. Anyone know if there is another device with a similar roller I can use as a replacement? (I'll be looking at the non-functional PB160 I have to see if it's trackball is similar.
3. The power jack for the 7.5v input is cracked. I did briefly test with an adapter and it was charging the battery, but the jack moved when inserting the barrel, which I imagine over time will cause problems with the soldered connection to the board. It appears to be a DC005 jack, but if anyone else can confirm, that would be great.
4. I tried two different batteries, one with the super capacitor enhancements that allows use of the Portable with no battery, but plugged into the wall (although I did also attach a 6v sealed lead acid battery in it because I don't trust my power plug yet). It worked fine. I also tried a 6v LiFePO4 battery with no supercaps installed. The LiFePO4 battery had decent voltage, but gave me a warning that there was insufficient power immediately on startup and the machine shut down right away. I had read others had used the LiFePO4 battery and thy worked well, in addition to being considerably lighter. Any thoughts?
5. I still need to replace the capacitors in the inverter board for the backlight. I believe it is the same board as the M5126 model, and is a known source of problems. Mine looked good, but might as well get it replaced while I'm mucking around in the machine.


One additional bit of work I have planned is to try to model a Portable battery charging stand where you can take a Portable battery and drop it on a charging station, hooked up to a 6v slow charger to allow me to charge up my extra portable battery when not in the machine. This will allow me to not rely the power adapter, which are harder to come by.

Thanks again everyone (especially Androda) for all the help with this machine. I think this is going to end up being one of my favorite machines.

 

[Androda]

4. I tried two different batteries, one with the super capacitor enhancements that allows use of the Portable with no battery, but plugged into the wall (although I did also attach a 6v sealed lead acid battery in it because I don't trust my power plug yet). It worked fine. I also tried a 6v LiFePO4 battery with no supercaps installed. The LiFePO4 battery had decent voltage, but gave me a warning that there was insufficient power immediately on startup and the machine shut down right away. I had read others had used the LiFePO4 battery and thy worked well, in addition to being considerably lighter. Any thoughts?

Two thoughts on the LiFePO4. First, it might need time to charge up to full voltage. Second, your hybrid's battery level reporting opamps might be showing the wrong charge level. This happens with hybrids that have seen just about any level of capacitor fluid ingress, it gets into the precision resistors on the PCB and then stuff swings all over the place.

 

[wottle]

I did think about that Hybrid module when it complained about the battery level. But when the lead acid battery didn't, I wondered if it was something with the LiFePO battery. I may try to replace the hybrid module, then. Thanks!

 

[Sideburn]

Congrats. I also Just got my BlueSCSI, adapter and ram upgrade and finally finished my repair / restoration from a dirty old non working junker I got off eBay.

all finished aside from my display I tried to fix and made even worse


• corrosion clean , cap kit, hybrid board, ram upgrade and BlueSCSI

• resin printed floppy eject gear
• 3d printed battery repro
• 3d printed TPU rubber feat
• lots of scrubbing and cleaning and a little retrobrite on the spacebar…

if you need or want any 3d printed parts let me know

 

[Sideburn]

if you need or want any 3d printed parts let me know

I’m going to try to make some new trackball rollers today out of TPU…