Must Reset PMU to Start Up

Question

Level 1

9 points

Must Reset PMU to Start Up

I am a little at a loss. I have to reset the PMU every time I start up. Once I am started up everything works fine except if the kids try to play one of their games it freezes and then I have to reset the PMU to start up again. (Well they tried to play Frozen throne twice and I won't let them try any more games for now.) I tried changing the battery and I tried unplugging removing battery, pressing start, and then letting it sit for awhile, then replacing battery and resetting PMU. It started up fine but still needs reset after every shut down.

I have a G4 AGP Graphics originally 400Mhz now with 1.2Ghz processor that has worked fine for a couple of years. It has 640mb RAM, 2 ATA hard drives neither of which is the original, and the original ATI RAge 128 Pro video card.

The ethernet port stopped working correctly just recently and I thought maybe it was the ethernet card so I temporarily networked to my Mac Mini via firewire till I could look into and fix that. However this has started happening in the meantime. I get the chime and the drives and fan power up, the power button light is on, the led light on the motherboard is on but no communication out of the computer to the monitor or network.

Any help you can give me would be greatly appreciated.

G4 1.2Ghz, AGP ATI Rage 128 Pro, 640mb RAM Mac OS X (10.4.6)

Posted on Jun 11, 2006 10:25 AM

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Answer 1

bhgdfh

Level 2

316 points

Jun 13, 2006 10:02 AM in response to Terry Long

sounds like your mobo is dying take it to an apple tech an have them run the diagnositic cd

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Answer 2

Terry Long Author

Level 1

9 points

Jun 13, 2006 10:09 AM in response to Terry Long

Well, that's not very good news, I was hoping maybe it was the PSU. I guess I will have to have it checked out.

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Answer 3

The hatter

Level 9

61,031 points

Jun 13, 2006 10:21 AM in response to Terry Long

RAM. 640MB = 256 x 2 + 128MB. Maybe. The 128MB SDRAMs were often 'slow' and would kernel panic under OS X, be too slow (especially with cpu upgrade sometimes).

Make sure your RAM is 8 nanosecond or faster. If you can boot OS 9 (even CD) then download and run DIMM First Aid and see what it displays. ("Okay" will only mean that RAM has SPD code for CAS Latency).

With all that freezing you need to stay on top of making sure the system drive is not corrupted or in need of repairs also and look for data corruption.

How is the battery?

Sonnet? OWC? PowerLogix cpu? does it require software etc?

You may want to do a cold boot and zap pram also or instead. Or boot into Open Firmware (command option o f) and reset nvram from there:

reset-nvram
set-defaults
reset-all

Much easier than resetting the PMU.

And on those restarts, boot into Single User Mode (CMD + S) and run fsck.

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Answer 4

Jun 13, 2006 12:55 PM in response to Terry Long

Can you boot to OS 9? If so, is it stable in OS 9? DIMM First Aid requires classic OS. DIMM First Aid http://www.versiontracker.com/moreinfo.fcgi?id=10415

Check this site for battery part numbers and sources.
Mac PRAM, NVRAM, CUDA/PMU & Battery Tutorial
http://www.geocities.com/texas_macman/pram.html

Local Batteries Plus stores also have Mac batteries. Here's the part numbers & prices.

1/2AA 3.6V Lithium, P/N LITHS14250BA, $8.99 + local sales tax
4.5V Alkaline, P/N COMP3LF22BP, $14.99 + local sales tax

Cheers, Tom

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Answer 5

Terry Long Author

Level 1

9 points

Jun 13, 2006 1:58 PM in response to Terry Long

Thanks for all the help guys.

I will try to go through all these suggestions. I did change the battery already, however, and it is same size and brand as the one I took out. I bought it at Batteries Plus in town.

My Ram is 2 cards, one 128 that came with the system and one 512 and they have worked for quite awhile.

The processor is OWC and didn't need any software when I installed it and has been working for a couple of years.

I did repair permissions and did a disc utitlity drive repair, ran both a couple of times to make sure. It did do what it called a minor repair on the hard drive the first time (I guess I should have written down what it said it repaired it was a bit map of something but that doesn't tell you much). There also were permissions to repair but then there always are.

How would I check for data corruption?

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Answer 6

bhgdfh

Level 2

316 points

Jun 14, 2006 3:32 PM in response to Terry Long

what do you mean the ethernet is not working 'correctly' ?

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Answer 7

Jun 14, 2006 5:24 PM in response to Terry Long

Re: <How would I check for data corruption?>

Get DiskWarrior by Alsoft
http://www.alsoft.com/DiskWarrior/index.html

Cheers, Tom

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Answer 8

The hatter

Level 9

61,031 points

Jun 15, 2006 2:25 PM in response to Texas Mac Man

The data corruption I was referring to was caused by 'bad RAM' and while DW is great, it doesn't find file content errors, only file fragment problems and problems in the catalogue directory.

Memtest would help tell you if the RAM was okay, along with knowing what DIMM First Aid says (booted from OS 9, not OS X or OS X Classic).

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Answer 9

bhgdfh

Level 2

316 points

Jun 20, 2006 7:20 PM in response to The hatter

The only way to really check your RAM is on a stand-alone unit. Some places have these but they are expensive.

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Answer 10

Jun 20, 2006 11:34 PM in response to Terry Long

Hi, Terry!

The Hatter's first post here is loaded with good tips, IMO. Please read them carefully and ask questions if you don't understand something there.

First and foremost, please insure you're backed up. Forced shutdowns can cause drive directory and/or data corruption which sometimes makes a drive totally inaccessible. Follow up any sudden shutdown with fsck, a Safe Mode boot, or Disk Utility booted from the install disc.

You might try a "deeper" reset of your PMU/logic board. Please refer to Tom's tutorial link; just above the Batteries section, there's a great tip on what to try when your Mac seems to lose its mind. You might try that.

I'd follow the Memtest advice as well. Most of us don't have access to RAM bench testers and rely on Memtest which often does pinpoint a problem, should one exist.

You also might consider disconnecting all of your peripherals except the keyboard, mouse and monitor, disconnecting your hard drive cables, resetting the PMU, booting to the install disk, then shutting down and attempting to boot to the install disc a second time. If you do, let us know if it rebooted to disc okay, or if it again needed a PMU reset.

This might sound dumb, but please check to insure that your new battery is inserted with the proper polarity.

Gary

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Answer 11

Terry Long Author

Level 1

9 points

Jun 22, 2006 3:23 PM in response to Terry Long

Okay, I think I have tried most everything you all suggested except the Open Firmware boot, which I still plan to do. I tried the reset suggested in the section about "computer losing it's mind," I do have the battery in correctly, I booted into OS9 and ran the DIMMFirstAid and do have results from that:

When OS9 was booting, before the extensions booted, I got a message:

The built in memory test has detected a problem with the cache memory. Please contact a service technician for assistance.

After OS9 booted I ran DIMMFirstAid and got these results:

Model: PowerMac3,1
PowerMac G4 (AGP Graphics)
DIMM0/J21
DIMM configured for 512MB
8008040D0A02400001705400820800010F04060101000E755400000F0E0F2540
1508150800000000000000000000000000000000000000000000000000001204
0000000000000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000064FF
7.0ns PC133-222
DIMM checks out OK

DIMM1/J22
DIMM configured for 128MB
8008040C0902400001A06000800800018F04060101000EC06000001414143210
2010201000000000000000000000000000000000000000000000000000001226
ADFFFFFFFFFFFFFF013756363531363031425446472D3130532020424148993B
01C11E00000000000000000000000000000000000000000000000000000064F5
10.0ns PC100-322
DIMM checks out OK

DIMM2/J23
DIMM not configured
no DIMM present

DIMM3/J24
DIMM not configured
no DIMM present

All your DIMMs checked out OK

According to the test my RAM checks out. If the speed of my cards is included in any of that, I don't know how to tell but I suspect it says that my 512 card is 7 nanoseconds and the 128 card is 10 nanoseconds?

As for the ethernet, well it just stopped working and I can't connect to my network or online via ethernet any longer. In fact, I suspect, that being networked to this computer contributed to the demise of my old DSL modem/router but don't know how to prove it. When I try to connect to my current router I don't even get any acknowledgement lights from the port I am using.

Where do I go from here? I can still try the resets using the Open Firmware boot but suspect I have already gotten the necessary clues from the OS9 boot. I am unclear as to where the cache memory is located. Is it on the processor, the logic board, or elsewhere? Thank you so much for your time and help on this.

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Answer 12

Terry Long Author

Level 1

9 points

Jun 22, 2006 3:27 PM in response to Terry Long

Ah, I still have the double booting to the instal disc to try but after the big reset today I was able to restart after changing the startup disc and restart into safe mode as well without havingto reset the PMU but at this moment have not tried actual shut down and then booting.

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