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No startup chime or screen on Powerbook 150


New member

I recently picked up a Powerbook 150. It was in bad structural shape. I fixed the structure, but it does not work (nothing on screen, no backlight or anything and no sound other than the HD spinning up and seeking) The cables and everything in there seem to be fine, except for that there are two empty ports on the logic board, one of which is for a modem card, which i do not have, but the other would appear to be for some sort of RAM expansion. I hear people talking a lot about RAM expansion, and it seems to be in every powerbook, but mine is missing it. The powerbook has not been recapped btw, but I want to know if there is some simple fix before I order capacitors (local shops closed due to pandemic)

Thanks in advance!



Well-known member
Hi - welcome :)

The Powerbook 150 has onboard 4MB RAM, so it doesn't need any additional cards to function.  I'd check your power brick voltages before all else - most of these have now failed and need a recap.  Failing that, I use a 7.5V 2.0A generic power brick which does the job.




Well-known member
Just to make sure: Consider to alter setting of brightness and contrast sliders for the display.

Edit: Might the PB150 be one of the machines that will not chime and boot if the buffer battery for PRAM and Clock is depleted? As far as I remeber, the 1xx series PowerBooks have a rechargeable battery soldered onto the inverter board. It easily can be confused with a non rechargeable button cell. If the PB150 in this regard acted like a LC475, it might help to let the machine sit for a while connected to the external power supply.
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also make sure when you put it back together you get the sliders on the pegs of the brightness and contrast sliders so you are actually moving them. too many times I have forgotten this and had to go back. You can tell if they are on by how free they move. Really free means you do not have them lined up...