PowerMac G4 MDD Boot Cycle D:

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PowerMac G4 MDD Boot Cycle D:

So I have this 2002 PowerMac G4 MDD dual 1.33GHz that refuses to boot sometimes, and I cannot figure out why!

I just replaced the power supply, though Im not 100% positive that this new one is in perfect condition. I have to check the volts later.

I currently have a 80GB drive with 10.5.8 in it and sometimes it boots, other times I get the screen with the apple logo on it, then black screen, then it does one of two things. It either repeats and goes to the logo then black screen, then logo then black screen forever, OR it goes from the apple logo to a black screen and stays black and I can hear it doing something inside. Apperantly the speaker is broke and when I plug in headphones I hear the startup chime over and over and over with about 6 seconds between them EVERY time. Why?

I have tried using a different GPU, no effect. Booting from 10.4 CD or DVD, or 10.5 DVD, no effect. Still Apple logo then black screen. I took out the battery and hit the little button on the motherboard when it was unplugged and that didnt help. I can feel the heatsink and its hardly even warm at all, so not overheating...

Does anyone have any solutions? Im about to pull my hair out! I'd love to get this back in everyday usable condition, not just "once in a while" working machine!

Thanks in advance guys! If you need any more info on this machine, Id be happy to provide it, along with pics~

Powermac G4 MDD Dual 1.0GHZ-OTHER, Mac OS X (10.5.8), PowerMac G4 MDD Dual 1.33GHz

Posted on Jan 6, 2013 9:22 PM

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Answer 1

bubbamj Author

Level 1

11 points

Jan 6, 2013 10:29 PM in response to bubbamj

I just tested the PSU with the directions from here: http://www.jcsenterprises.com/Japamacs_Page/Blog/D275729F-09DA-4FBB-96B3-BEEEB2C 04619.html

and its fine up until step 5, where my +3.3V shows as 3.3 and VERY VERY quickly drops down to around 0.7v. Then step 6 is for +5v, and my readings for that was +17v! I tested it multiple times with the same result. I even tried other red cables and they all were identical at 17v instead of 5v.

Is this a SECOND bad PSU?

Any reccomendations? Id rather get another OEM one, but they are soooo pricey! Are the ATX mods easy? I dont want to destroy my Mac case to do it...

Also, is this the ONLY reason it has a boot loop? Seems odd to me....

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Answer 2

japamac

Level 7

24,400 points

Jan 7, 2013 3:03 AM in response to bubbamj

+3.3V shows as 3.3 and VERY VERY quickly drops down to around 0.7v.

Capacitor leakage? Voltage regulator compromised?

Then step 6 is for +5v, and my readings for that was +17v!

Complete loss of regulation? Not good.....

Double checked the voltmeter setting for 12v? Properly zeroed? I trust that you did, but just checking...

Is this a SECOND bad PSU?

Not looking good....

Also, is this the ONLY reason it has a boot loop? Seems odd to me....

That part is hard to say. I'd be interested in what a Verbose mode boot shows.

Are the ATX mods easy?

The connector rewire is the hard part and you lose +25V, so no Firewire or ADC. One could run with an adapted ATX and the door open for testing, though.....

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Answer 3

bubbamj Author

Level 1

11 points

Jan 8, 2013 9:15 AM in response to japamac

I'm quite new to volt meters, and can barely use mine... How do I check those settings or zero it? My model is Innova 3320

https://www.google.com/url?sa=t&source=web&cd=3&ved=0CDwQFjAC&url=http%3A%2F%2Fw ww.walmart.com%2Fip%2FEquus-3320-Innova-Auto-Ranging-Digital-Multimeter%2F146446 66&ei=2FPsUJT1KaSt0AHr7oCYDw&usg=AFQjCNGNt6HmHukde-ddt-gP-9PauASiWg

I'm using the 10 MegOhm input DCV setting for the voltage checks. Is that wrong?

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Answer 4

japamac

Level 7

24,400 points

Jan 8, 2013 1:24 PM in response to bubbamj

Switched to DCV, either AUTO or 20V.

The meter is auto zeroing, so no worries there.

10 MegOhm input

Ohm is for resistance measuring.

AC/DC Voltage measurement

To avoid possible electric shock, instrument or equipment damage, do not attempt to measure voltages above 600V AC/DC. This is the maximum voltage that this instrument is designed to measure. The "COM" terminal potential should not exceed 300V AC/DC measured to ground.

1. Plug the black test lead into "COM" jack of the multimeter then plug the red test lead into the "V" jack.

2. Set the multimeter's Function/Range Selector switch to the appropriate ACV or DCV position as desired .

3. Place the red test lead onto the positive ➕ side of the item being tested and the black test lead onto the negative ➖ (across the source/load) side of the item. Be careful not to touch any energized conductors with any part of your body.

4. Read the results on the display.

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Answer 5

bubbamj Author

Level 1

11 points

Jan 8, 2013 8:27 PM in response to japamac

Does that mean I shouldn't use the "10 MegOhm input DCV" setting on the dial? Which do I use then? The only other DC ones as far as I can tell are "DC mA" and "DC10A" settings. The others are all AC, then there is battery load testing for 1.5v, 6v, 9v, and 12v...

Sorry for the inconvenience!

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Answer 6

japamac

Level 7

24,400 points

Jan 9, 2013 2:31 AM in response to bubbamj

I just looked at the user manual, enlarged the photo of a 3320 and could see the "10 Mega ohm input impedance" over the DCV. Yes, use that one. The impedance rating is for those who need to know (need to balance with output impedance), should not be of importance in the PSU test and only served to confuse me.

Sorry. I still use an "antique" analog multimeter.....

Given that, it would seem that you can trust the readings that the meter gave you.

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Answer 7

bubbamj Author

Level 1

11 points

Jan 13, 2013 10:01 PM in response to bubbamj

On a side note, my MDD's power light will go on when I turn the machine on, but as soon as I release my finger it turns off. Is this a power supply issue as well?

Also, trying to flash a 5.70 BIOS 7800 GS to Mac, and I cant seem to find the right version of nvflash. They all seem to just sit there and do nothing... Tried 5.13 and 5.127.

"nvflash --check" produces:

"NVIDIA Firmware Update Utility (Version 5.13)

Adapter: BR02 (0F5h) (10DE,00F5,FFFF,FFFF) B:01,AGP,D:00,F:00"

Under that is a blinking "-" and I let it sit there for half an hour. Came back and it was still just sitting there blinking. The heck?

Ive tried nvflash 5.127 too, and that one doesnt even do anything AT ALL besides flash the dash at me. Doesnt even say "NVIDIA Firmware Update Utility"

What do I do? Thanks!

Message was edited by: bubbamj

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Answer 8

japamac

Level 7

24,400 points

Jan 13, 2013 10:18 PM in response to bubbamj

my MDD's power light will go on when I turn the machine on, but as soon as I release my finger it turns off. Is this a power supply issue as well?

A commonly reported symptom of a failed PSU.

Isn't the command a:\>nvflash --index=X -4 -5 -6 -j nvmac.rom accepted after the check?

GeForce 5/6/7 How-To

Maybe try this for Geforce 7xxx cards:

http://downloads.guru3d.com/nvFlash-v5.63---NVIDIA-Firmware-Utility-download-186 2.html

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Answer 9

bubbamj Author

Level 1

11 points

Jan 13, 2013 10:25 PM in response to japamac

I will try that version, thanks!

japamac wrote:

Isn't the command a:\>nvflash --index=X -4 -5 -6 -j nvmac.rom accepted after the check?

It doesnt even go back to "A:\" when I do the check. It sits there blinking like its doing something, though I dont think it really is, therefor I cannot even RUN the command after that! D:

Thanks for the quick reply by the way. Would love a faster way to communicate with you if possible...

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Answer 10

bubbamj Author

Level 1

11 points

Jan 13, 2013 11:11 PM in response to bubbamj

Here is what happens with all of my attempts... It just sits there like this:

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Answer 11

japamac

Level 7

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Jan 13, 2013 11:32 PM in response to bubbamj

Does the card work in Windows?

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Answer 12

bubbamj Author

Level 1

11 points

Jan 13, 2013 11:43 PM in response to japamac

No, it doesn't.

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Answer 13

japamac

Level 7

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Jan 13, 2013 11:46 PM in response to bubbamj

Dead card.

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Answer 14

bubbamj Author

Level 1

11 points

Jan 13, 2013 11:59 PM in response to japamac

Shouldn't be. Worked fine a year ago and I had it stored in its own drawer inside a static bag. No visible signs of wear or anything. It was on a Mac ROM back then, but I wanted to flash it to the OCed ROM, as my card is the BFG OC version to begin with. If it was dead, why would it even show up on the nvflash at all?

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Answer 15

japamac

Level 7

24,400 points

Jan 14, 2013 1:57 AM in response to bubbamj

It was on a Mac ROM back then

Well, that explains why it doesn't work in Windows.

If it was dead, why would it even show up on the nvflash at all?

A ROM may be readable but not flashable; that I have encountered several times.

However, I ddn't know that you were working with an already flashed card.

I can't be sure, but it may be that NVFlash wants the ROM erased before proceeding?

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