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    What size and angle for a PowerBook 145B screen polarizer?

    Cheers. Hey, I thought it was risky posting pics of a Windows machine here… but I did it for the simple reason that it’s a similar 14.1” TFT to the G3 PowerBooks (and I haven’t done one of those yet) :) Glad this group has the maturity to see through the situation!
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    What size and angle for a PowerBook 145B screen polarizer?

    Yes. The angle of the film must be opposite the angle of the front film, ie. to achieve a black-out condition when the LCD is off. Because the film is stuck to the other side, it is effectively ‘flipped over’. You can get 135-degree film to oppose the 45 but I haven’t needed it, I think if you...
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    What size and angle for a PowerBook 145B screen polarizer?

    Cheers. I am not an expert in this, as I am yet to find the best replacement film to use. The link I posted to matt film seems promising; glossy film is not forgiving at all and scratches easily (see below). I was reasonably successful on a PC laptop with TFT screen, where I replaced the front...
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    What size and angle for a PowerBook 145B screen polarizer?

    Here is a similar process on the Powerbook 150 which I did not succeed with. The replacement film introduced sepia colours - purple/blue/yellow instead of black/grey/white - and it seems I also broke the ribbon connections in handling which gave a strange shifted effect to the display. Anyone...
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    What size and angle for a PowerBook 145B screen polarizer?

    It doesn’t actually matter if you are replacing both the front and rear polarisers, which I think you are - with the screen in that condition. The brown blotch comes from the rear polariser in my experience. The angle is 45 degrees originally, but I’ve used 90-degree film on the front and rear...
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    ADTX SCSI IDE 2.5 inch Adapter Compatibility and Performance

    Thank you, I will get both of those. Apple SC Setup and FWB toolkit both recognised and formatted the drives but I think the problems with mounting are because both drives are over 4GB. Does that mean they have to be HFS+? That would mean System 7.5 or later - I guess the original Disk Tools...
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    ADTX SCSI IDE 2.5 inch Adapter Compatibility and Performance

    For the record, today I’ve also tried using two IDE 2.5” slim (12.7mm) drives from the late 90s: a Toshiba 4GB and an IBM 6GB. Both are detected by the adapter and by Apple SC Setup. Both will format and verify (a process that takes about four hours). Neither will mount at the end of that...
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    ADTX SCSI IDE 2.5 inch Adapter Compatibility and Performance

    Thank you for your work in testing/benchmarking. I think you’ve saved me a lot of time and puzzlement. The 1GB drive I have seems to have significant rotational noise (similar to the earlier drives), I will try to replace with another small IDE laptop drive of the period. I agree with your...
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    ADTX SCSI IDE 2.5 inch Adapter Compatibility and Performance

    This is an extremely useful post for me - thank you - very timely too. I found it by a Google search for “scsi 10ta32”. One of these IBM 1GB Apple-branded drives with the same adapter arrived in my Powerbook 540c (with smashed LCD). I was trying to use it with a cheap CF-IDE adapter that looks...
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    PowerBook 540c Restoration Project

    Ah, I have not, thanks :) The PRAM battery actually seems to have come back to life in my 540c, I should test the battery behaviour in that. Someone noted the PRAM battery charges once the main battery is charged, so I’m giving the other a little time as well. I might also try a bench power...
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    PowerBook 540c Restoration Project

    Hmmmm... I'm sorry to have wasted your time on those things. I have a second battery which worked for a while but now my 520 doesn't detect; perhaps I have the same problem as you. Mine is definitely in the battery as my other battery works OK in the same 520. I noticed fairly early on that...
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    PowerBook 540c hinge restoration: SUCCESS!!!

    I don't have the software to remix but I think I've found a quick kludge for this - the 'Negative Part' modifier in Orcaslicer. Intersecting a 40mm sphere with your design at a carefully-chosen position produces a result that I like, though I worry the resolution of the sphere may be a little...
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    500-series alternative power supply learnings

    I think so, yes. I don’t know how to add a current-controlling circuit, so perhaps if you find one, please let us know, I’d be keen to try it :) I guess then a single power supply can be used, with the current-controlling circuit acting on the Vbatt line, and the full power supply current...
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    PowerBook 540c hinge restoration: SUCCESS!!!

    I’ve made the improvement I wanted to - the fit is tighter now and clips in well (even with the display in place). I’ve updated the Thingiverse page.
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    500-series alternative power supply learnings

    That is a ‘shunt’ - a precisely-known (very low) resistance in series with the cells, across which a tiny voltage is measured by the battery’s controller. This voltage is proportional to the current flowing in, or out, of the battery cells. Current is measured in series, voltage is measured in...
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    500-series alternative power supply learnings

    Exactly - I was surprised at how the voltage and current weren’t controlled when the greater current was available. cheesestraws and mdeverhart have explained it perfectly. I think the Vbatt half of the original supply is a “current source”. It regulates its voltage to provide a maximum of 1A...
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    PB 5xx original AC adapter re-cap & modern replacement

    I probably should have posted in this thread - sorry - but I have started a new thread with my theory of why two supplies are needed. It seems to me that VBatt must be limited to about 1A, or the battery will attempt to charge with all the current available. Please see my post at...
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    500-series alternative power supply learnings

    I have a 500-series power supply that worked beautifully after a re-cap - then after a week or two, it went pop. It seemed a MOSFET had shorted - and then a spark jumped from that to the transformer leg, eroding a PCB track. But actually, the MOSFET tested fine on removal. The problem appears to...
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    PowerBook 540c hinge restoration: SUCCESS!!!

    Thanks - I meant to make one improvement today - I’ve realised (by looking at a removed top case) that the pointy end should have a fairly long tag on it to engage with the case (as your design does). All mine were broken off, so I put on a clip the same as the other two clips. The two side...
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    PowerBook 540c Restoration Project

    It sounds a bit like the problem I was having when the ribbon was making poor contact to the battery cells (corrosion…) - voltage seemed correct but the measured current was irregular when charging, and then it didn’t detect at all. To fix it, I soldered wires between the battery tabs and the...
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