• Hello MLAers! We've re-enabled auto-approval for accounts. If you are still waiting on account approval, please check this thread for more information.

PB 520 dead :(

traz

6502
Hello there :)

I've been the proud owner of a second-hand PB 520 for the past 4 or 5 years. In that time I've only used it sporadically.

The past couple of times I've used it I started getting booting issues. The first time I reset the power manager and it worked. The second time it didn't. I put it away for about a year and have dug it out again, trying to resurrect it for the past couple of days without success. It's been plugged into the mains continuously since then (I have no batteries for it)

No noises, no lights, nothing comes up. Completely dead. Tried someone's suggestion of plugging another keyboard and using its power button - didn't work.

From reading a few threads on here and elsewhere, the PRAM battery is dead, because the date was always 1909 or whatever, and when it started up the screen was always white and I had to muck about with contrast to get it back in order. But that was pretty much from the day I bought it.

Any suggestions? And sorry for the long-winded post.

 
It could be a problem with the power adaptor connector. Try plugging it into the back of the machine and giving it a gentle wiggle about and try to switch the PowerBook on. The connector pins have a habit of bending slightly which can cause contact issues - I've had to straighten the pins on my 520c a few times after no-power scenarios like yours.

 
Thanks for your suggestion :)

I've tried the wiggling a few times without success. :( I notice that one of the pins isn't exactly the same height as the others (little bit shorter)... got some tweezers and tried to do some mucking about there but the pins are very strong and it wouldn't yield in the slightest. Might try and bend them a little bit. I think some of them might be very slightly bent.

Thanks again :)

 
UPDATE: as I was walking past I thought I'd give the power key yet another go...

IT WORKED!!!!!!! I almost jumped out of my skin as I heard those sweet chimes

Well it worked for all of 10 seconds. It was unresponsive to my commands and then a window came up saying that there is not enough power in the battery and that it will be shutting down in 10 seconds, which it did. A battery icon also appeared in the top left of the menu bar as it was powering down. I recall that the low battery window came up a few times the last time I used it.

So I guess I'll keep it plugged into the wall for another few days and see what happens? Or hunt down a new PRAM battery if at all possible?

 
You might want to get a multimeter and check your power adapter. All four center pins provide power, with the outside ring as ground. If you search around on here you'll probably come across a post listing which pins provide what voltage. Or if you have an Apple service manual, you could use that.

When my 540c stopped powering up, it turned out that it was a bad fuse (next to the AC plug) in the power adapter. I don't recall any power line anomalies around the time it died, but then the thing is well over ten years of age, so maybe it just got tired and gave up. Anyway, I had to solder a new fuse in there, but the holder it uses is very tight; I broke the old fuse getting the end caps off, and they wouldn't fit on the new fuse, so I just soldered two bits of wire to the ends of the new fuse and soldered those to the PCB. It works great now.

Unfortunately the power adapter wouldn't come apart without disfiguring the casing, so mine is now coated in duct tape with an Apple logo drawn on with a Sharpie.

 
LOL @ the drawn Apple logo :)

Thanks for the tip. :) As it happens, my father took the AC adapter away last night. He's an electronics technician and knows a lot more about all of this than I do (but knows zip about Macs). While I've had it plugged into the wall the past few days, it's felt warm but it was always like that. I think my last adapter was like that too. Anyway, he thinks it's overheating so he insisted I stop using it until he runs some tests.

 
Yes, it's normal for the adapter to get warm during normal operation.

Do you have any rechargeable batteries installed in the Powerbook? I can imagine a malfunctioning/dead battery (shorted) will give the AC adapter problems. If you have batteries installed, then try removing them - the AC adapter should be able to power the PowerBook by itself.

 
If you're seeing these power problems without any laptop batteries installed, then something is screwy. A dead PRAM battery won't cause these problems - mine was dead for years before I replaced it.

 
I agree with the power supply being possibly bad. I don't know the voltage of the 520 series. it may be on the bottom of the laptop on the UL sticker. Another problem with these old Powerbooks is that the electronic components get old and fail. I have a Powerbook 3400 that worked great, then I tried to turn it on one day and it died mid boot sequence with an burnt electronics smell. I collect these things but I get more paranoid about turning them on as they get older.

 
I got a PowerBook 520 now. I could probably take a measure of the leads tomorrow and tell you the voltage for each. Then I will post it on my site so you can recreate it :D

 
Thanks for the replies :)

You guys are the experts! And I'm pretty sure you're right about the power supply being f**ked.

I bought a 540C yesterday complete with power supply; it looks in better condition than the 520's one. Same model number so I'll be able to plug it into the 520. I'm pretty confident that everything will be good again.

Coius, thank you for that... don't know if you ended up doing it, but I would love to pass those voltage measurements on to my Dad so he might be able to fix the 520 power supply for me.

Cheers :)

 
Back
Top