Possible PMU issue ? Or GPU fan?

[Melchieor]

Greetings Everyone


Today I have a peculiar issue with a PowerBook A1138 1.67 . I noticed two things : 1 the battery doesn’t charge . Sometimes the charger turns orange for a brief moment but mostly green. I tried a second battery with same result . Both batteries could be dead although system profiler says it’s good (Tiger 10.4.11) . I tried PMU reset by holding shift + ctrl+option and same result. 2nd: the gpu seems to work well until sometime when the frame rate drops and then goes back up and then drops again . I installed istat pro widget and see the right fan is at 0 rpm. Curiously I opened up the laptop and lifted the gpu fan and indeed the fan doesn’t turn on . I figured I need a new fan but when I tried another PMU reset I could see the fan spinning . Any thoughts ?

 

[Melchieor]

So I had the idea of running geek bench on both this system and an 867mhz TItanium and the results were about the same actually. Only off by a few points . There’s something definitely odd here .

 

[Melchieor]

Ok i have a theory . I have seen MacBook Pro’s get very slow whenever the battery is at critical level . Since the battery is at essentially 0% , Is it possible that the same thing is happening here ?

 

[AphoticD]

I don’t think the 1138 had a processor performance control option (Automatic/Highest/Reduced) did it?

What is the output of ‘pmset -g’? If you see ‘reduced 1’ then the CPU is being throttled by the PMU.

The Apple Service Manual for the PBG4 15” DLSD here has some steps under troubleshooting for no battery charge which you could try.

Do you get any faults under Self Diagnostics in System profiler? Try locating the AHT or ASD disc for this model at archive.org (or possibly the garden) and try to run the firmware test suite.

Also just to rule it out, try removing and/or shuffling/reseating RAM to give things a kick.

 

[Melchieor]

Thanks for the suggestions . I ran the command pmset -g and it resulted with battery 1 and ac power -1*. I’ll downloading the apple test disc and read the manual link. Thank you.

 

[Melchieor]

Ok, an update. Spotlight was affecting the benchmark . Turning off spotlight or letting it finish led to results which are on par with geekbench benchmark scores (>900 with this model). So really the outstanding issue is why the battery doesnt charge ? Trying with a second battery is the same. Neither even light up when the button is pressed. I noticed that the charge light would turn orange sometimes for a few moments and then back to solid green. I tried finding the AHT specific to my Powerbook but I wasnt able to find y one for the A1138. Does anyone know which one I can use? The manual states 2.5.2 however when I try this , it also doesnt seem to work. When starting the CD , it mentions its not for this Mac and then only has 2 options :restart and shut down. If someone has a link they can share with the AHT for this model , that would be great.

 

[Raging Dufus]

It's possible your DC-in & sound card (combination card on one PCB) has failed. This is a known weakness on the aluminum PB's, and usually it manifests on the power side of things rather than the sound side; i.e., your sound will still work fine but you may lose the ability to charge a battery, or sometimes cannot power the machine at all.

If you're up to a little surgery, here's an iFixit guide that will help you replace it:

PowerBook G4 Aluminum 15" 1.67 GHz DC & Sound Card Replacement

This guide will show you how to replace the DC & Sound Card on your PowerBook.

www.ifixit.com

I don't know where you live, but in the U.S. the part can often be found on eBay, here's an example (MODS: not my auction).

 

[Melchieor]

Thanks! I am in the US so that auction would work however it’s for a different model , would it work ?

 

[Raging Dufus]

Thanks! I am in the US so that auction would work however it’s for a different model , would it work ?

I believe it's the same part number, 820-1602-A, across different 15" PB models. Apparently iFixit thinks so too, because I found that eBay listing by clicking the link under the "What you need" section of the iFixit repair guide I linked above, which is for your model of PowerBook. Look near the top of that repair guide under "What you need" where it says "Available for sale on eBay." Click the link and it will take you to an eBay search that returns that eBay listing as the first option.

Bottom line: yes it should work. But if you have concerns, use that repair guide to pull the old one out of your PowerBook and compare it to the photos in the eBay listing.

 

[Melchieor]

Thanks. I have gone ahead and purchased the part. I’ll keep this posted updated once I get it and install.

 

[B S Magnet]

I don’t think the 1138 had a processor performance control option (Automatic/Highest/Reduced) did it?

It did not, no. I can attest this, as the A1138 I use as my Clouded Leopard/SL-PPC mule has never had a working battery, and I’ve still managed GeekBench benchmarks well in excess of that listed on Everymac.

the battery doesn’t charge . Sometimes the charger turns orange for a brief moment but mostly green. I tried a second battery with same result . Both batteries could be dead although system profiler says it’s good (Tiger 10.4.11) .

Pull up Coconut Battery 2.6.6 and have a look at what each battery presents.

With my A1138’s dead, OEM battery (which has never worked since I bought the laptop in 2019), it shows the battery is depleted (the upper bar); the lower bar still shows it’s designed with a capacity it does not actually yield. The power adapter, from time to time, will glow amber instead of green, but the battery is not charging.

It's possible your DC-in & sound card (combination card on one PCB) has failed. This is a known weakness on the aluminum PB's, and usually it manifests on the power side of things rather than the sound side; i.e., your sound will still work fine but you may lose the ability to charge a battery, or sometimes cannot power the machine at all.

I’d be really intrigued to learn this is why @Melchieor ’s batteries won’t charge but their system still powers up. If so, I’d like to know what on that board is failing. I haven’t had to replace the DC-in board on the A1138, but I have on the A1139; on the latter, it abruptly failed with a tiny pop and the system going dark.

 

[Melchieor]

It did not, no. I can attest this, as the A1138 I use as my Clouded Leopard/SL-PPC mule has never had a working battery, and I’ve still managed GeekBench benchmarks well in excess of that listed on Everymac.



Pull up Coconut Battery 2.6.6 and have a look at what each battery presents.

With my A1138’s dead, OEM battery (which has never worked since I bought the laptop in 2019), it shows the battery is depleted (the upper bar); the lower bar still shows it’s designed with a capacity it does not actually yield. The power adapter, from time to time, will glow amber instead of green, but the battery is not charging.

Thats exactly my issue. I have purchased the DC board as suggested by @Raging Dufus . I hope that enabled the Powerbook to charge again.

 

[B S Magnet]

Thats exactly my issue. I have purchased the DC board as suggested by @Raging Dufus . I hope that enabled the Powerbook to charge again.

You’ll need to follow-up on this thread after you’ve swapped the DC-in boards. I’d like to hear how that went for your A1138.

As for the fans:

You will be much better off refurbishing it on your own — which amounts to opening the fan assembly and cleaning it out. Then, find a specific lubricant you can get at your local hardware store — a lubricant for power tools. HEre in Canada, this is what I use, and it is how I’ve revived my PowerBook fans (all four of them) and most of my MacBook Pro fans.

Lastly, if you’re not already using it to manually activate the fans to run, grab G4FanControl and tinker with the sensor temp settings until you can verify the fan(s) are running. I have found the default settings by Apple lets the CPU and GPU cores run much higher than they need to on the A1138/A1139 series.

 

[Raging Dufus]

I’d be really intrigued to learn this is why @Melchieor ’s batteries won’t charge but their system still powers up.

I have purchased the DC board as suggested by @Raging Dufus . I hope that enabled the Powerbook to charge again.

I hope it works too! It was just a shot in the dark, but it's exactly what I would've done in the same circumstances. If it doesn't change anything, well - at least you'll have a spare part that you're likely to need some day. I've had to replace that board a couple of times. Think I may even have some spares still hanging around, even though I don't have any complete/functional AlBooks anymore.