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

53 replies

beigebox Author

Level 1

28 points

Aug 24, 2026 2:26 PM in response to beigebox

I think I’m going to store this 2.5 external case for now. I’m not comfortable trying different adapters to get it to power up. Risking damage that is likely to happen to the circuit board, the hard drive or something else!

I have an extra 3.5 hard drive installed in my Powermac 7600. I’ve ordered the correct HDI30 to C50 adapter cable (590-0718-A) for the purpose of putting the PB180 in target disk mode. Planning to copy it’s content to that drive by drag n drop so I can at least have a backup.👌

beigebox Author

Level 1

28 points

Jul 6, 2026 4:25 PM in response to Jan Hedlund

I thought about trying the scsi disk mode using the special system cable. The problem is I have no video so I can’t get to my control panels on the Powerbook to change the ID

Same issue connecting to an external monitor…can’t get to the monitors control panel.

What if I disconnected the internal screen cable? Would it then be forced to display the desktop to the external monitor?

And regarding the 10 dip switch adapter, If I set the pins to 1,4,7,8,9,10 “on” it shows the desktop pattern but no HD icon

beigebox Author

Level 1

28 points

Jul 7, 2026 5:19 AM in response to beigebox

So I’ve tried another route…

I remember configuring this PB to file share with my Powermac 7600 before the video crash. Also, I’ve connected both computers using localtalk adapters between printer ports. Both adapters are properly terminated.

The Powermac can see the PB in the chooser. However, when I enter my credentials there’s no checkbox to mount the PB! Assuming it’s because I need to be in the PB chooser to enable sharing details.

I know System 7 sometimes defaults to the modem port so I switched the localtalk adapter there to no avail.

Thoughts or suggestions? Thanks!

Jan Hedlund

Level 7

24,993 points

Jul 8, 2026 7:04 AM in response to beigebox

First of all, did you try the PowerBook Display sequence described earlier? Was it possible to enable video mirroring, in order to get the full PowerBook 180 Desktop (with a menu bar) on the external display?

beigebox Author

Level 1

28 points

Jul 8, 2026 12:38 PM in response to beigebox

I’m about ready to conclude the HP1907 monitor is just not compatible with the 640x400 (?) resolution for the PB180.

I’ve tried all relative adjustments on the monitor itself to no avail. The blank desktop pattern is magnified so i think it’s blowing the HD icon off the edge so it’s hidden.

I would still like to try and get the PB HD mounted on the Powermac 7600 desktop via Localtalk and file sharing. I have it shared but haven’t figured out how to mount it. Again, the limitation here is that I have no internal video on the PB.

Jan Hedlund

Level 7

24,993 points

Jul 8, 2026 4:14 PM in response to beigebox

It used to be here:

download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/Utilities/Network_Access_Disk_7.5.sea.bin

download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/Utilities/Network_Access_Disk_7.5.txt

You should be able to find the necessary PowerBook Display control panel on the existing PB 180 hard disk. Could be copied to the 7.5.5 Power Macintosh 7600 via SCSI disk mode.

beigebox Author

Level 1

28 points

Jul 29, 2026 5:03 AM in response to Jan Hedlund

Jan, the PowerBook 180 has bedn working flawlessly. Thanks again

I want to connect an external scsi hard drive (Apple formatted IBM 320MB 2.5 drive) to this computer via the HDI-30 SCSI connector with Centronics-50 port.

The case that I have looks like this:

https://ebay.io/m/qFAjoV

I I have a DB25 adapter to use with the Centronics 50. I have the ID set to 2. There are no other scsi devices daisy-chained.

Should I use the other port on the scsi case for termination or should this work “out of the box”?

Attaching the user manual

https://i.ebayimg.com/images/g/FXEAAeSwlOZqaKm3/s-l1600.jpg

https://i.ebayimg.com/images/g/QtYAAeSw5eRqaKm3/s-l1600.jpg

https://i.ebayimg.com/images/g/OFcAAeSwDCFqaKm4/s-l1600.jpg

beigebox Author

Level 1

28 points

Aug 9, 2026 11:44 AM in response to beigebox

100% 2.5' SCSI I drive compatible
Daisy chainable, up to 7
Quick rotary SCSI ID Switch
Designed and built by aftermarket Apple service provider
Apple II SCSI, DB-25 external enclosure, 2.5" SCSI case, vintage Macintosh external drive, NOS SCSI case

Acceptable power sources (not included):

ABD cable (mini-din connector)
AC/DC adapter +5V/1A (3-mm jack)

Jan Hedlund

Level 7

24,993 points

Aug 10, 2026 7:43 AM in response to beigebox

An external power adapter capable of 5 V DC (1.0 A) output should be OK for the pictured IBM drive (which requires 0.5 A). Alternatively, a special ADB power cable may be used. Make sure that the tip polarity (centre positive) is correct for the hard drive storage case. Can the hard disk be heard spinning?

Termination can be tricky and may require a few extra experiments.

Jan Hedlund

Level 7

24,993 points

Aug 10, 2026 8:31 AM in response to Jan Hedlund

Jan Hedlund wrote:

/.../

Alternatively, a special ADB power cable may be used.

/.../

Correction:

The maximum current draw for all Apple Desktop Bus (ADB) devices connected to a PowerBook 180 is 200 mA (0.2 A), so power supplied via a special ADB cable from the PB 180 ADB port would not be suitable in this very case. Use a separate power adapter instead.

beigebox Author

Level 1

28 points

Aug 10, 2026 8:57 AM in response to beigebox

I have not tested the adapter. Footnote- it’s new and has a led light on it which is very bright when plugged in. I notice it dims and flickers when powering up the external. Not sure what that means?

I may try a couple of extra adapters to see if that makes any difference

Jan Hedlund

Level 7

24,993 points

Aug 11, 2026 8:28 AM in response to beigebox

Important:

I have a 2.5" hard drive storage case that looks VERY much like the one in your pictures. Similar case, similar connection board with the ID switch, one DB-25M, one DB-25F, a hard drive connector, and a power inlet.

I have not used this case for a long time, and I am not sure about which power adapter once was used. However, a quick inspection of the case connection board (including a comparison with an IBM H2xxx Sx pinout) appears to indicate that my device has a centre negative (!) power inlet. That is, not centre positive.

I know that all your documentation says centre positive. It is quite possible that this really is correct for your device, but in order to avoid damage to the drive, please try to verify this.

Does the power adapter label have a polarity icon?

Did you receive an ADB power cable with the case? If so, you could check the 5 V output polarity with a multimeter at the barrel-type DC plug when the ADB power cable is connected to the ADB port of a Macintosh computer (make sure that the computer is off when connecting/disconnecting anything to the ADB port).

beigebox Author

Level 1

28 points

Aug 20, 2026 5:13 AM in response to beigebox

Regarding the 2.5 external, I find it odd that the 44 pin scsi interface includes the four power/ground pins to match the one in the Powerbook 180, and the enclosure also has the 5V 1.5A power plug required to power on!

This seems contradictory to me?

beigebox Author

Level 1

28 points

Aug 22, 2026 5:20 AM in response to beigebox

I verified with a multimeter that the adapter is center positive and supplying +5V 2A. The drive still doesn’t spin up when connected and the adapter light dims and flickers.

IYO, would a 3A adapter solve this?

BTW, if you have a similar external case and not using it I am an interested buyer🙂

Jan Hedlund

Level 7

24,993 points

Aug 22, 2026 7:25 AM in response to beigebox

Hello again,

A 5 V DC power adapter capable of supplying up to 2 A should be adequate. My adapter (a centre negative model from Sicon Peripheral, Taiwan) provides up to 1.5 A according to the label.

BTW, my enclosure is also from Sicon. Thank you for your interest, but I would like to keep this device as a backup, just in case. If necessary, I hope that you can find another similar product.

One should perhaps not rule out that something is limiting the output current in your power adapter, but another possibility may be a wiring issue inside the external hard drive enclosure.

Do you have access to another (universal?) power adapter with a suitable plug for a test?

The hard drive spins relatively quietly. A sound should be heard with merely power connected to the external case (without a SCSI cable).

Vintage PowerBook display & PRAM issues post-HDD replacement