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PowerBook 520c Display Issues

Posted by: akator70 on 2026-04-01 12:04:23 This 520c display was working fine in January. Yesterday I booted it up to discover this strangeness on the bottom right of the screen. It's different almost every time I boot. I have swapped different displays and cables and those are ruled out, this is definitely an issue with this display. Is this a capacitor issue or something else? Thanks!

Posted by: 3lectr1cPPC on 2026-04-02 08:42:37 ACF ribbon bonding issue or a failing driver IC. Likely the former. Essentially, the issue is that the ribbons around the LCD are attached to the LCD matrix via a specialized ACF bonding machine, and you need one of those machines to fix it (they cost way too much money for anyone outside of factories/large-scale refurbishes to buy them) You can sometimes get away with using another source of heat to re-adhere the ribbons, but this usually doesn’t work. Basically the LCD is hosed 🙁

Posted by: akator70 on 2026-04-02 09:00:45 Thanks. Sad but not unexpected.

Posted by: 3lectr1cPPC on 2026-04-02 13:09:10 Just to rule it out, you should try reseating all the connectors going from the motherboard to the LCD.

Posted by: akator70 on 2026-04-02 13:15:31 Everything has been ruled out except what's in the LCD unit itself — I've swapped other displays into the same machine and they work fine. Are you referring to the LCD board that's inside the LCD's metal frame?

Posted by: 3lectr1cPPC on 2026-04-02 18:19:50 By "LCD unit" do you mean a complete display assembly? Because there are multiple connection points inside the display assembly which may be loose and should be reseated to make sure it's actually the LCD module that's at fault.

Posted by: akator70 on 2026-04-02 18:24:53 Exactly that. I have ruled out the 520c motherboard, interconnect, cables, inverter board, etc. basically everything except the LCD assembly. I'll open that up and check everything, maybe I'll get lucky...

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