View Full Version : MDD not booting

23rd August 2004, 06:42 PM

Today, i decided to use a light paintbrush and vacuum cleaner to cleanse quite a few parts of my MDD powermac. after removing most of the copmponets, video card, memory, modem, and processor board, i suck away most of the dust, after re-assembling, i turned him on, but no "BONG" sound the power button light when you hold it down but then nothing, the HDD spins up and the led on board lights and the fans spin, then after about 20 seconds, the fans spin to max speed and the thing nearly takes off. but no bootup, no screen signal, and no keyboard/mouse lights.

It's only like 9 months old so i'm a little upset if anyone had any ideas of what this may be, let me in on it. I really hope i didn't bugger up the logic board or something!!!!

thanks in advance

23rd August 2004, 07:41 PM
first thing i'd try is removing easy parts and booting like that - eg: ram. Maybe you haven't seated it properly? I can only give advice as far as troubleshooting a PC which wont start - where it generally comes down to cpu/ram/expansion cards.

23rd August 2004, 08:33 PM
Strip the machine down to the absolute minimum you can to get a working machine - usually this involves using 1 stick of working RAM along with your graphics card. Don't bother plugging in the optical or hard drives.

If that fails, hold down the CUDA switch on your motherboard for 10 seconds. Next, reset the PRAM. Removing the processor card was the likely cause of your problems here, I reckon.


23rd August 2004, 11:43 PM
damn, none of those suggestions worked. I suspect resetting the PRAM is not possible because i don't even think it looks at the keyboard. up i'll keep trying, but it doesn't look good. I would put it down to something bad, but i was extemely carful with everything i did, and i've done it before with no problems. If anyone has a MDD powermac 1.25 can they pull the ram out and restart and give me results of what happens, and also with the video card?

Thanks again in advance.

24th August 2004, 12:35 AM
Static may have killed it? It's probably the worst case to happend but vacume cleaners does cause static electricity, and offcourse statics are no good to electronic components especially a motherboard...

Just my 2c, although it could simply be nothing and it will be fixed by the next time i check the forums. What ever the problem may be I hope you can get it back and running again soon.

24th August 2004, 05:18 AM

Byrd, I'm afraid to say, the advice you just gave him will have definitely crashed his PMU. The switch in a MDD is *not* a CUDA switch, it's a Power Management Unit reset, and pressing it for longer than a second will result in death of the PMU without a doubt. The machine now will not ever again go into sleep mode after crashing it.

I had an MDD that at one stage wouldn't boot - the solution was to unplug the machine, remove the battery, and leave the machine for 24 hours in that state.

I hope the machine is still under warranty because it's very likely the motherboard is dead.

24th August 2004, 09:21 AM
My bad then - was going off similar advice I received to repair a beige G3, B&W and 9600 machines. Surely they wouldn't place a button there if it wasn't to be pressed to reset the machine to default settings.


Edit: what I've typed above does not contraindicate any other site that I've searched for involving non-booting G4 Macs. Pretty much all sites recommend the PMU button be pressed for 5 - 10 seconds should the machine have problems booting.

24th August 2004, 03:59 PM
Unfortunately, Apple have done just that. The purpose of the PMU reset switch is to fix problems with the PMU not allowing the machine to boot, or, for when a motherboard is exchanged, to cause the PMU to set itself correctly.

It can only be pressed, once, for less than a second. The machine must be booted before it can be pressed again, if the PMU is not to crash.

24th August 2004, 11:30 PM
well i held it down a good 30 seconds and now my machine is screwed!

Just kidding, i dunno what is wrong with it but i took it to apple today, so hopefully will get him back soon.

It's not under warranty which sucks, but they said the quote plus first hour labour is 99 so thats not that bad if it will render my machine useable once more . but they said, it sounds like a logic board problem, how much are these? and has anyone ever had any replaced?

kim jong il
25th August 2004, 07:10 AM
I was just reading this thread and decided to a brief bit of research and was surprised that Power Manager resets/issues/crashes are not covered by warranty although Apple publish the PMU reset and troubleshooting procedure in their knowlege base 'for educational purposes'. (This seems, to me, to be a semi admission that there may be issues with it. Apple are positively phobic about people poking around inside their machines so instructions on how to do this is a surprise).
I also found further articles regarding the PMU reset switch. Some say 'a fraction of a second', one said '5 to 30 seconds' so I wonder how critical the time actually is (I must say I have doubts about this author as he displays a scary degree of ignorance on an unrelated topic. e.g. to change an ATA drive from slave to master you just have to put it in the top drive bay! when in reallity it should not care where it is so long as the jumpers are set correctly). One thing they ALL agree on is that whatever you do, DO NOT push the button twice as this will crash the PMU.
It seems to me that the MDD PMU must have flakey firmware as numerous people seem to have issues with it.

Also, logic board = motherboard = $$$

Good luck, I hope it all works out.

cheers, kim

25th August 2004, 09:40 PM
really?, thats gay, i am a student you see, saving for it in the first place took me the better part of 2 years. and that was only 3 grand, man, if its gonna be over 600, i can't even afford to have it repaired. And what if its the processor. how much are these? i read that i can buy a dual 1.42 ghz processor for cheap off ebay and whack that i there? this true?

Starting up a 'fix Jim's Maccy' fund. Wanna donate?

25th August 2004, 09:46 PM
A mate of mine got me a replacement motherboard for my DP450 at cost, but the standard price is over $1100 for most of them. Try leaving it unplugged with the battery removed for a day and see if that works. If it doesn't, then your motherboard is very likely dead.

25th August 2004, 09:55 PM
A few more links I've found involving non-booting MDD G4s:

Google Groups 1 (http://groups.google.com.au/groups?hl=en&lr=&ie=UTF-8&threadm=8ruwa.50854%245M.2808056%40twister.southea st.rr.com&rnum=15&prev=/groups%3Fq%3Dmdd%2Bmac%2Bnot%2Bbooting%26start%3D1 0%26hl%3Den%26lr%3D%26ie%3DUTF-8%26selm%3D8ruwa.50854%25245M.2808056%2540twister. southeast.rr.com%26rnum%3D15)

Google Groups 2 (http://groups.google.com.au/groups?hl=en&lr=&ie=UTF-8&threadm=yfHKc.1061627%24Ar.898658%40twister01.bloo r.is.net.cable.rogers.com&rnum=11&prev=/groups%3Fq%3Dmdd%2Bmac%2Bnot%2Bbooting%26hl%3Den%2 6lr%3D%26ie%3DUTF-8%26start%3D10%26sa%3DN)

Accelerate your Mac (http://bbs.xlr8yourmac.com/ubb/Forum29/HTML/000541.html)

The XLR8 link is the best ... but pretty much reiterates what we've said!

I'd test your MDD power supply - this site (http://haertle.ch/tinker/ps/)details you on how to go about it. Seems they have pretty high failure rates.


26th August 2004, 11:23 AM
well, the wonderful people at MAC1 in fyshwick, have completed inspecting my machine, and they drew the wonderful conclusion to tell me something i already knew... "Yeah mate sorry to tell you this, its either the logic board, or the processor board", 'so not the power supply?' "nah mate logic or processor". 'wel thanks for charging me 99 bucks and wasting a week of my time to tell me something i already knew!" Click

he also said a new logic board is around 400
and a new processor is around 800
and it could be both....


what should i do. I'm thinking of saying, alright replace the logic board, coz i CAN afford that, just, and then if that doesn't fix it, finding a third party upgrade cpu, or getting a second hand one off ebay somewhere?

any ideas. BTW byrd, thanks for the links, while being a little off topic, have been an entertaingin read on there own, esp the MDD powersupply bit

BTW its not powersupply which is gay, coz its the cheapest part!

26th August 2004, 11:26 AM
You may as well upgrade it. :)
streetwise (http://www.streetwise.com.au/redirect.php?action=url&goto=www.streetwise.com.au/default.php?g=100&visitorid=AT) stock upgrade cards for powermacs.

26th August 2004, 12:18 PM
no such upgrade for MDD g4's yet, i was refering to a genuine apple dual 1.42 ghz processor module, hmm if only i could find sucha thing!

27th August 2004, 10:55 AM
There's a single 1GHz MDD CPU module on ebay at the moment,
last I looked it was at $300.

Like yourself, I'm waiting for a dual 1.25GHz or 1.42GHz module. :/ I think we'll have to wait a while before Sonnet et al bring out their own ones.

EDIT: fixed typo.

27th August 2004, 11:28 AM
yeah thats gay, when your machine is screwed until you fix it. I'm gonna go with a new logic board, and pray night and day that that will fix him...... :(

27th August 2004, 12:25 PM
My mac isn't broken thankfully, it's just 867MHz DP.
Is your MDD the FW800 model?

27th August 2004, 10:21 PM
no its the 167 mhz buss one with DDR 2700 ram, single 1.25ghz processor (was)

The apple guy rang babck today, saying it was the processor, so if i can find a cheap one, i'll be happy, else its 860 bananas for an apple replaced one.

i did find this site but have'nt been able to get in touch with the guy
may be of interest if we can bulk order some processors...


kim jong il
27th August 2004, 11:01 PM
fastmac http://fastmac.com/index.php in the USA sell and will ship processors to Australia (Sonnet will not). The cards have an extremely low fail rate and may be worth a look. Shipping is around $50 US (fed ex) + GST on its value to retrieve it from Australian customs

27th August 2004, 11:27 PM
thanks but llike i mentioned earlier, its a MDD g4, the last model before g5, the only way i'm gonna get a processor is a genuine appel one. ie they don;t make upgrades yet. thanks anyway though, i've been wanting to upgrade my digital audio g4 for a while now too..

28th August 2004, 12:45 AM
if push comes to shove you can always start bidding on this. (http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&category=4601&item=5117834150&rd=1&ssPageName=WDVW)

28th August 2004, 05:38 PM
would it work though? i'm under the impression, it wouldn't. whaddayareckon???

28th August 2004, 06:19 PM
Originally posted by Jimbo@Aug 28 2004, 05:38 PM
would it work though? i'm under the impression, it wouldn't. whaddayareckon???
If you're talking about the single ghz module on ebay i don't see why it shouldn't work. I'd guess the processor modules are very similar if not the same. failing that you can swap out the processor from your current cpu module.
With the single GHz CPU, I'm guessing it would probably be the same part as your 1.25GHz CPU, but just under clocked.

Anyway, it seems like your most economical option. You can always cast it off back to ebay if worst comes to worst B)

28th August 2004, 08:26 PM
Actually, come to think of it - it wont work!

The 1Ghz module has a 133MHz bus, your 1.25Ghz (single or dual) has a 167MHz bus so you can rule out the eBay processor board for now.

29th August 2004, 12:27 AM
you can overclock the bus though can't you?
in fact, my calculations indicate that would be the only real difference between the 1GHz and the 1.25GHz.

29th August 2004, 02:26 AM
yes you can overclock the bus. Info can be found here. (http://www.hardmac.com/article.php?id=4)

29th August 2004, 11:41 AM
Originally posted by Atomic@Aug 29 2004, 02:26 AM
yes you can overclock the bus. Info can be found here. (http://www.hardmac.com/article.php?id=4)
Thanks for the link! It's the most informative one I've seen :)

30th August 2004, 11:26 AM
Never clean a computer with a brush and vacuum cleaner. The rush of air actually creates a tremendous amount of static which can destroy things.

I've seen it happen. And now I have heard about it too.


30th August 2004, 12:01 PM
hmm well i now know that :( just a shame i had to find out the 800 dollar way :D

Oh well, i'll just get it fixed for freakin heaps of dollars, luckily i do have job and will be able to pay off a small loan from my girlie...

30th August 2004, 12:06 PM
As an alternative, those cans of compressed air work well - i've heard of people cleaning their powermac's with them without any problem. You just blow the dust out of there.
Here are some pics: http://sharkfire.net/gallery/OldMacs

30th August 2004, 09:13 PM
Its still a gust of air drifting by the chips. It still might cause grief.

I have found the best method to be used it submersing the object to be cleaned in a non-conductive liquid in an ultra-sonic cleaner.

All this can be had for around $100.00 from Jaycar. Probably cheaper if you look around.


30th August 2004, 10:34 PM
i should've taken a photo, the front air intake on the MDD mac looked like the inside of a vacuum cleaner bag.... gross! Anyway, i'm going in tomorrow to bite bullets and fork over $960 australian bananas and hopefully wil have maccy back by friday!

Good times.

11th September 2004, 12:36 AM
wow been one million years since it left but i paid fo it today, and its been repaired. YAY i get it back either sat (tomorrow) or mundy


One thing that shat me off was when the tech commented on my wallpaper, when i replyed, how did you get in, he was all like, oh we reset the password. I thought apple techs used CD to boot their hardware tests off, which annoyed me coz it meant he was using my computer! not that i do have anything to hide, except the word doc on my desktop called "the story of my life" which is a log of all the SMS i've sent and recieved over the years...!

11th September 2004, 01:46 AM
When I took my MDD into nextbyte to get looked at (Weird noises) they asked for my password right then and there....