Which Powerbook 180 caps shoud I replace?

[macman0512]

Hi,

I have recently aquired this nearly mint Powerbook 180, but the display is having errors(See the included picture in the thread). It's not the display cable or the actual lcd itself, as the amount of lines varies every time I try to power it on, so some caps on the display controller board are probably dead. I really don't want to crack this thing open without having the proper caps on hand, so I was wondering if anyone has the values of all the display board caps for me.

On a sidenote, how easy is it to switch the keycaps around? The current layout is Azerty and this really annoys me so I want to change it to Qwerty.

 

[desertrout]

This actually looks to me more like a grounding or connection issue on the logic board - corrosion around the battery terminals is a common issue, or perhaps the daughter board is loose. Cap issues on the inverter board would only affect brightness or contrast control, afaik...

Does the machine boot? (Do you get a chime and disk activity?)

But it's always good to replace the caps as well if you're going to be in there - and I also could be mistaken about the cause it actually is the inverter board. I tried to find a cap list, or even check my Digikey orders to see if I could nail down the exact caps... but nothing definitive. I *think* - pretty sure - they are:
1 x 33uF / 10V @ C1 (like https://www.digikey.ca/en/products/detail/nichicon/UMT1A330MDD1TP/4312532)
1 x 47uF / 16V @ C4 (like https://www.digikey.ca/en/products/detail/nichicon/UMT1C470MDD1TP/4312538)

Perhaps someone else can confirm.

But, candidly, opening the 180 to get to the inverter board so you can check for yourself is quick and easy, and you'll want to do this anyway to assess the state of the boards and verify good connections (and check for shorts if need be) - https://tim.id.au/laptops/apple/powerbook/powerbook_160.165.180.pdf

 

[macman0512]

Well, I found the issue. The display cable has ripped a bit thanks to a broken clutch cover. The left five traces are broken (the ones seperated by a bit more plastic than the rest). So I guess the next question I'm asking is, does anyone have a display cable for me?

 

[desertrout]

Ah shitty. Sadly I don't have an extra. Make sure to throw a flare up here on Trading Post and elsewhere (r/VintageApple, TinkerDifferent, AppleFritter, etc.).

As this might be difficult to come by, you *could* attempt a repair... I've successfully repaired the PB HDD cables before so it's certainly doable (I don't think the 180 cable is too dense, so using bodge wires may actually be an option), and there are vids on YT showing methods to try. But it's fussy work, and if the break is at a flex point the repair may not hold. I'd personally give it shot... nothing to lose except time.

 

[macman0512]

Ah shitty. Sadly I don't have an extra. Make sure to throw a flare up here on Trading Post and elsewhere (r/VintageApple, TinkerDifferent, AppleFritter, etc.).

As this might be difficult to come by, you *could* attempt a repair... I've successfully repaired the PB HDD cables before so it's certainly doable (I don't think the 180 cable is too dense, so using bodge wires may actually be an option), and there are vids on YT showing methods to try. But it's fussy work, and if the break is at a flex point the repair may not hold. I'd personally give it shot... nothing to lose except time.

I'll do that, thanks. I don't think the bodge wire would work, as it broke right at the point where it flexes the most, but I'll give it a shot.

 

[androda]

If trying the bodge wire doesn't work out, I'd be interested in the cable for duplication purposes. Display flex cables like these are starting to crack and die, so we need to be making new ones. I've had success with one cable so far, looking to do more over time.

 

[macman0512]

If trying the bodge wire doesn't work out, I'd be interested in the cable for duplication purposes. Display flex cables like these are starting to crack and die, so we need to be making new ones. I've had success with one cable so far, looking to do more over time.

If it doesn't work it's yours. Mind making me one if the bodge doesn't work?

 

[Cedsrepairs]

@androda (hey ! i've bought a couple of your scsi2sd ) I have the PCB layout for some Atari Portfolio flex cable (a part that sold 10,000s ) , would you be interested in those ?

 

[androda]

If it doesn't work it's yours. Mind making me one if the bodge doesn't work?

Maybe. Flex cables are pretty expensive though, on the order of $20 per cable as the raw manufacturing cost (set of 5, plus shipping), so it would be good to have a few people that want one before doing a test run.

 

[Cedsrepairs]

Bkack on topic I'm surprised to learn that there are caps to change on a PB180 (but this might well be true)

Last time I looked at mine it was 100% tantalum on the mortherboard, altough I don't remember if I took the screen apart or not.

my own PB180 is plagued by tunnel vision (runs around 30 min before it can be seen - I know there is worse than that) -
I have yet to see a PB180 not affected by this - I don't think it's worth recapping the screen (at least in my case).

 

[androda]

As I recall, the 180 is all tantalum on the motherboard, not sure about the display. The backlight control and inverter board almost certainly has an electrolytic.

 

[Cedsrepairs]

As I mentionned previously what's super frustrating with PB recaps is that Apple's vintage gray plastics are super brittle, and sometimes just to "make it even better by recapping a screen just in case" you end up breaking all the plastic tabs of the screen, or worse the ones that are fixed to the hinge - very fragile as well.

So I would only consider, for a powerbook, to recap what obviously is in need of a recap (too dim, contrls don't do anything,etc) and not touch the rest. But that's just my opinion.

 

[desertrout]

As I recall, the 180 is all tantalum on the motherboard, not sure about the display. The backlight control and inverter board almost certainly has an electrolytic.

I'll confirm there are no electrolytic caps on any on the PB1xx logic boards (except the 100 of course), nor any on the monochrome active matrix displays used in the PB1xx series. For the 170 and 180, the only electrolytics are on the backlight inverter board and the trackball board.

As I mentionned previously what's super frustrating with PB recaps is that Apple's vintage gray plastics are super brittle, and sometimes just to "make it even better by recapping a screen just in case" you end up breaking all the plastic tabs of the screen, or worse the ones that are fixed to the hinge - very fragile as well.

So I would only consider, for a powerbook, to recap what obviously is in need of a recap (too dim, contrls don't do anything,etc) and not touch the rest. But that's just my opinion.

I would suggest that fixing the brittle / broken plastics is a good reason to open these machines. Using a good two-part epoxy formulated for plastics to reinforce the stand-offs, or using 3D printed replacement solutions, allow you to use these machines again without worry, especially opening and closing the display. For example, this video illustrates a 3D printed hinge mount solution that I've personally never needed to use, but I know others have and works very well:

 

[desertrout]

If trying the bodge wire doesn't work out, I'd be interested in the cable for duplication purposes. Display flex cables like these are starting to crack and die, so we need to be making new ones. I've had success with one cable so far, looking to do more over time.

Oooh any chance you'd be up for duplicating a 190cs / 5300cs display flex cable? I've got two split ones (same spot on both, at the 45deg fold), and I'm 100% certain others do too...

 

[androda]

Oooh any chance you'd be up for duplicating a 190cs / 5300cs display flex cable? I've got two split ones (same spot on both, at the 45deg fold), and I'm 100% certain others do too...

Sure. These flex cable recreations are what I do with spare time, so they can take a little while to complete.

 

[desertrout]

Sure. These flex cable recreations are what I do with spare time, so they can take a little while to complete.

That's awesome. I'll DM you later