68kMLA Classic Interface

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Powerbook 100
Posted by: imactheknife on 2023-08-17 11:35:10
Anyone want to take a stab at two powerbook 100’s?? One had worked, but after recap nothing.. just typical black screen. I recapped one logic board with organic polymers no change. Just curious if anyone wants to try? Would like to know if displays are working at least too lol
Posted by: aplmak on 2023-08-18 04:46:06
You have to recap the 3.3uf 50v capacitors in the screen. I use a very tiny needle and gently pry up the little rubbery/gooey covers on the screw covers on the bottom of the screen. I forget how the front display comes off.. I think bottom first and you slide up. (Sorry I forget). Then once inside you have two caps to do on the inverter board (I use tantalum) and then on the back of the display is maybe 8 3.3uf 50v silver caps that are in black plastic cases. I wiggle them up and down till they come off.. I clean with a qtip all the electrolyte. DO NOT DOUSE the area with alcohol... it will leak into the display area.. did that once. Then remove the old corroded legs and try to clean off the pads. I've used tantalum dipped (smallest size) and I have had to angle them. That was until I was able to find size A tantalum capacitors that fit fine. It's a tricky area to work on. But with patience it can be done. Unless your CCFL light is gone.. which I have not seen one go yet on all mine. The screen always requires a recap. Good luck. I just posted about this and someone else just did this in another thread.
Posted by: GRudolf94 on 2023-08-18 04:49:31
For testing, the screen will run without the caps. However imactheknife's issue won't be that unless those caps' electrolyte has eaten away at the panel's vias. PB100s lose the screen voltages, circuitry for that is at the bottom right corner of the board next to the trackpad connector, and typically goes bad when that gets gooed all over by the caps there.
Posted by: 3lectr1cPPC on 2023-08-18 09:05:10
I believe that he's already recapped his LCDs.
Posted by: imactheknife on 2023-08-20 17:54:58
I believe that he's already recapped his LCDs.
Yeah, i have. Just curious to see if someone could test them on a logic board known to work. Oh well, leave in a box for another 20 years lol
Posted by: GRudolf94 on 2023-08-20 18:16:40
@imactheknife do you have a multimeter? Would be happy to walk you thru troubleshooting LCD_VEE circuitry and whatever else. Looking at other threads, before you might be tempted to chase non-issues, tantalums are ok in a PB100.
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