PowerBook 150 - no display, but screen is okay

Question

Level 1

59 points

PowerBook 150 - no display, but screen is okay

I just got an old PowerBook 150.

When I turn it on, I dont hear a start-up chime, but I do hear the hard drive spinning like it's loading up the System OS which I believe is happening.

However, the screen is blank (eg, no desktop displayed), but the screen does have a backlight that I change change the brightness high or low...

I've heard this could be a common problem with such an old laptop, particularly this one.

Anyone got any ideas on what to troubleshoot this?

Posted on Sep 15, 2013 12:00 AM

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Answer 1

dalstott

Level 4

2,639 points

Sep 15, 2013 10:38 AM in response to be236

I have one older mac laptop that resets the display brightness to the lowest point (black screen) due to no PRAM battery. Try using the brightness control which is next to the right hinge to go to maximum.

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Answer 2

be236 Author

Level 1

59 points

Sep 15, 2013 10:51 AM in response to dalstott

Already slid both contrast and brightness controls many times. No effect.

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Answer 3

Jan Hedlund

Level 7

22,129 points

Sep 17, 2013 1:56 AM in response to be236

Hi,

I guess that you have tried resetting both the Power Manager and the PRAM without effect.

http://support.apple.com/kb/HT1781

It may not be a bad idea to carefully examine all boards in the computer (use a magnifying glass). Look for leaking/cracked electrolytic capacitors, other damaged/discoloured components, and bad solder joints. Are all cables OK? Do not forget the circuits near the LCD and on the board with a loudspeaker.

Jan

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Answer 4

be236 Author

Level 1

59 points

Sep 17, 2013 7:21 PM in response to Jan Hedlund

Yeah, I tried the PRAM steps (didnt fix my problem), but what I did not hear was the beep or start-up chime as I would have expected. I'm wondering if that is the root of the issue.

Again, still, I can hear the hard drive spin as if the OS is loading.

I have not opened the laptop up yet.. is it hard to do, then I can look at all the components.. Usually no chime is because of bad RAM.. How does RAM go bad? This laptop has not been turned on for years, so maybe something got stale?

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Answer 5

Jan Hedlund

Level 7

22,129 points

Sep 17, 2013 11:34 PM in response to be236

A computer that has not been turned on for many years may have bad electrolytic capacitors. Depending upon the type, there could be leakage or just a crack. It is not even sure that a problem can be detected visually. An electrolytic capacitor may also (at least partly and temporarily) recondition itself after some use, which does not make troubleshooting easier.

It is not difficult to open the PowerBook (you may want to have a look at guides for similar models at, for example, ifixit.com). A set of small Torx screwdrivers would be needed. There are four screws underneath and one near the SCSI port.

Jan

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