Battery, charger, or worse?

September 10, 2010 12:43 PM

Powerbook G4-- not charging, plus intermittent high pitched buzzing noise, which stops when charger is removed. Still running when plugged in, but battery reads 0%. I'm hoping it's the charger, and not the battery-- anyone recognize this problem?

Bought it second-hand a few years back and it's always been a workhorse-- never any trouble. 1 GHz, Power PC, 768 MB DDR SDRAM, read the specs. The charger light is currently orange, but battery isn't moving from 0%.

posted by jokeefe to Computers & Internet (10 answers total)

If it runs on the AC adapter but doesn't charge the battery then the battery is my first guess. Lithium ion batteries degrade with time and if the battery has never been replaced it could be at least six years old, well outside the typical useful lifespan. If you want the problem to be an adapter you might only be out $30 or less from Craigslist, but it probably won't fix it. Other causes could be DC board.
posted by 6550 at 12:57 PM on September 10, 2010

Response by poster: Since I posted at 12:43 until now (12:59) the battery has risen to 2%. So it's still sort of charging... what's DC board? (And thanks for replying.)
posted by jokeefe at 1:00 PM on September 10, 2010

This seems really easy to test. Do you hear the buzzing when the battery is removed (and it's plugged in, of course)?
posted by ripley_ at 1:04 PM on September 10, 2010

Here's a DC board (note: this may not be the board for your model). If you look at the larger pic you can see that it has the connector that mates with the battery. Along with connecting the battery to the computer it's responsible for charging the battery, monitoring it's voltage, I guess that sort of thing. If the DC board is bad the battery and adapter could still be good and the battery won't charge. I wouldn't spend $60 to replace it on a PowerBook even if you knew the DC board was bad, though. It'd be better to put that money towards a new(er) laptop. Plus there'd be the cost to have it installed, if you couldn't do the work yourself.

But I still think it's the battery. Maybe let it continue to attempt charging and see if it brings it back. I'd probably feel if the battery was getting too hot (if you can't keep your hand on it it's too hot). And probably wouldn't just leave it unattended (like letting it charge while you go out to dinner). Yeah, that's maybe overcautious. But in rare cases lithium batteries have caught fire.

A new battery from a place like OWC will probably run you $100, which, like the DC board, is pretty expensive given the value of the PowerBook. You could try a used battery off Craigslist but with the age of the PBs you might end up with a battery that's on it's last legs as well, which would be a disappointment. If you do go used try and test it in your laptop first to make sure it doesn't run down in 20 minutes or something.

Sorry I don't have great news for you.
posted by 6550 at 1:19 PM on September 10, 2010

Response by poster: ripley_: A little while ago, the battery ran down completely (it was at about 23%, and it put itself to sleep-- this is normal for it, actually, it's always done that). I had it unplugged at the time, because the buzzing was driving me mental; I plugged it in again, and the buzzing has stopped, yay, but the charging is still going very very slowly (up to 3%, which has taken 25 minutes since it was at 2%). The good news, I suppose, is that it's still working fine while it's plugged in, and I backed up everything to my external drive last night just in case (it had been a couple of months since the last backup).

I'm guessing it's the battery... thanks for detailed replies, 6550, as well.
posted by jokeefe at 1:28 PM on September 10, 2010

You may be able to get Apple to replace the battery for free if it's serial number falls within the ranges listed here: https://support.apple.com/ibook_powerbook/batteryexchange/main?id=qp. I got a new battery for my 12in G4 this way a few months ago; I did have to call in though since the form on that page didn't accept my info.
posted by bizwank at 2:15 PM on September 10, 2010

Probably need a new battery, but just in case... Have you tried resetting the PMU?
posted by supercres at 2:54 PM on September 10, 2010

Bet your battery has a short in one of its cells.

That could make it draw too much current from the recharger when fully discharged, and if so, the buzzing noise could be an automatic circuit breaker cutting in and resetting itself on a rapid cycle. The buzzing has stopped because the minimal charge you've achieved is enough to reduce the current below threshold levels for the circuit breaker.

Seconding 6550's advice to monitor it closely as you charge it.
posted by jamjam at 4:13 PM on September 10, 2010

If you choose "more info" from "About this Mac", under Power it will list the condition of the battery. I've had it show there that it needs to be replaced, and got a new one for free at the Apple Store.
posted by olecranon at 9:56 AM on September 11, 2010 [1 favorite]

Response by poster: Thank you all for your answers. I'll be replacing the battery.
posted by jokeefe at 11:47 AM on September 11, 2010