Level 1

28 points

Vintage PowerBook display & PRAM issues post-HDD replacement

i have a vintage Powerbook question…

I was switching out the hard drive recently. When I powered up the screen was lit but then dimmed automatically (the screen had been working fine) had random horizontal lines and I can’t see the desktop in the background.

So I got the Apple video adapter cable to connect to the external port and a 10 dip switch adapter to connect my HP1907 vga monitor.

When powering up I get a desktop pattern but no desktop icons. I can’t select mirroring settings because I have no internal screen.

Tried to zap the PRAM but the computer doesn’t give me the second chime. This is odd. I’ve never had this happen on any of my macs.

Looking for a solution. Thanks!

Posted on Jul 6, 2026 7:29 AM

39 replies

Jan Hedlund

Level 7

24,815 points

Jul 8, 2026 5:19 PM in response to beigebox

You're welcome! Do not hesitate to post back if you have further questions. Good luck!

beigebox Author

Level 1

28 points

Jul 10, 2026 6:24 AM in response to Jan Hedlund

Jan, I can’t get to the PB hard drive to copy the necessary monitor control panel.

Would it be possible to ftp all files that you used to create the network floppy? I would be most grateful.

beigebox Author

Level 1

28 points

Jul 12, 2026 2:42 PM in response to Jan Hedlund

Yes the Powermac 7600 is connected to the internet.

I will try to get those files downloaded and on a floppy.

Thanks!

Jan Hedlund

Level 7

24,815 points

Jul 12, 2026 3:38 PM in response to Jan Hedlund

Correction

>Once on the PM 7600, drag the files onto StuffIt Expander for encoding/decompression.

Should read:

Once on the PM 7600, drag the files onto StuffIt Expander for decoding/decompression.

beigebox Author

Level 1

28 points

Jul 14, 2026 10:22 AM in response to Jan Hedlund

Jan, I'm happy to report that I have successfully mirrored my PB 180 to my external monitor, per your instructions.

Thank you so much! Excellent guidance.

Jan Hedlund

Level 7

24,815 points

Jul 14, 2026 12:11 PM in response to beigebox

Hello,

Glad to hear that. Thank you for the report and the kind words.

Jan

beigebox Author

Level 1

28 points

Jul 29, 2026 5:51 PM in response to Jan Hedlund

Thanks. I will look through the manual

beigebox Author

Level 1

28 points

Aug 10, 2026 8:26 AM in response to beigebox

No the drive doesn’t click or spin up.

I verified that it’s fine by temporarily installing it in the PB180

Jan Hedlund

Level 7

24,815 points

Jul 6, 2026 10:30 AM in response to beigebox

Thank you for the information.

The reason for the internal display fault could perhaps be something like a bad cable connection, a solder joint, or a capacitor problem.

>When powering up I get a desktop pattern but no desktop icons. I can’t select mirroring settings because I have no internal screen.

This is a normal behaviour for some models when connecting an external display without being able to watch the internal. The standard control panel setting is typically to extend the Desktop. Unfortunately it is often not possible or easy to change the setting to mirroring (if at all available) since the control panel is not visible on the extended part of the Desktop.

In one such case I seem to remember that I managed to use a separate startup floppy with a small macro application (programmed via another similar computer) that allowed an automatic change to mirroring.

Vintage PowerBook display & PRAM issues post-HDD replacement