G4 MDD Logic Board or fan problem ?

I recently posted thinking my problem was a dead battery.
I replaced the battery and still had the problem.
here's what happens:
Once the G4 MDD is powered up and heats up, the fan comes on and stays on high speed. Eventually it sends the G4 into sleep mode.
Once this happens, I can't wake it up or power it down, unless I pull the power cord.
After replacing the battery, I reset the PRAM. no luck.
I also tried resetting the PMU, no luck.
I think there is something wrong with the logic board or the other fan (the one directed at the heat sync).
The heat sync is extremely hot, and the larger fan that is directed at the heat sync does not turn on.
I just found this article when I did a search for power mac G4 fan: http://docs.info.apple.com/article.html?artnum=95038
in that article, it mentions 2 LED's that should be either both on or both off, and there is only one of these LED's that is lit.
<1. Power Macintosh G4 (PCI Graphics): Check LEDs DS7 and DS8 on the logic board. In a working unit, these LEDs should be in sync with each other: both on or both off. If one LED is on and the other is off, there is a problem.>
any idea what this means ?
Is it a fan problem, or a logic board problem ?
This G4 was in storage for 5 months during a move, if that clues anyone in to what is going on.
thanks in advance for any ideas,
Steve

Hi
If it were me I start by assuming it's a simple problem with the fan as it would be the easiest and cheapest thing to replace. It should be spinning to expel the hot air around the heat sink fins out of the back of the case. I expect the computer reaches a certain temperature and goes into sleep mode automatically to prevent any permanent damage to the hardware.
Replacement instructions can be found here:
http://www.info.apple.com/usen/cip/pdf/g4mdd/g4mdd-lowerfan.pdf
I'd start by checking the fan's power connector is still fully seated and the fan isn't clogged up by dust etc. You could also try giving it a help in hand by giving it a spin with the point of a biro to see whether it's just sticking.
I'm not sure how relevant the article you linked is, as if refers to a much older model and I think it's only applicable if the computer is completely dead, i.e. no power and no fan movement.

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2x iMac G5: Both Logic Board and Display Problems, Warrenty?

Hello,
Thank you for looking at this topic.
I am Jeroen from The Netherlands and proud owner of several Mac Mini's, iMac's and Macbook's. I have 2times the iMac G5, a beautiful machine, but both not working since 2 months.
I have two times the iMac G5 with iSight, both have logic board and display problems.
The first iMac doenst start at all, black screen, i hear the chime, but nothing happening. After a minute i see one horizantal white stripe but nothing happens.
The second iMac has weird horizantal stripes also, but the computer starts. It gives a finder and questionmark icon. After a while the fans go crazy.
Both these symptons are widely known on the internet. I would like to get this fixed, but prices are crazy. And because this is a common issue I would expect to get this fixed for no costs. I have contacted several Apple resellers but they shown me high prices and bad services. On these forums I've saw people in the USA who get this fixed free of charge.
Does anyone has any advice for me? I'll call apple USA this morning.
Thankyou for ur time.

Welcome to Apple Discussions.
I know of no repair extension authorization which provides for the repair of either computer you describe beyond its original 12 month period of coverage. If either machine is covered by a warranty extension program provided by AppleCare, then the parts, labor or both required to replace the defective components may be offered at no charge to you. Final determination of eligibility is made at the part level by authorized Apple service providers or dealers and by the specific serial number of the machine submitted for service.
Absent a warranty extension, however, it is quite likely that you will have to pay for the repairs is you elect to have them performed.

New logic board, still boot problems with Turbo Fans

I bought a 2Ghz dual G5 from a guy on craigslist and he told me that the Geniuses at the Apple Store said it had a bad logic board. So I bought a brand new logic board from DVwarehouse.com, and installed it along with a new set of matched RAM from Crucial, a new HD, new PRAM battery, new video card and a new superdrive. The only thing original are the processors and power supply (and fans, of course).
When I start it up, after the chime it quickly goes into "turbo-fan mode", which I have read that means the Op Sys didn't load correctly. Many restarts later, I was able to reset the nvram in the Open Firmware, but that didn't seem to help at all. I also pressed the SMU button (according to Apple's directions), but that didn't help much either.
I've had a few successful boots, but always with the fans going full blast. I though that once I got Leopard loaded onto the HD, then it would calm down with a software update. But before I ever get that far, the G5 hangs. Sometimes the G5 will boot and access the HD but hangs soon after. Sometimes I can get it to boot off the Leopard DVD. But most of the time it just boots and sits there slowly spinning up the fans into turbo mode.
The few times it has booted to access the HD or DVD, the fans go turbo right away. Other times it will boot with a chime, but then it won't access the HD or DVD and I get noting on the display.
I should say that this behavior is almost identical to how it was acting before I replaced the logic board. But how can that be? It should be a new computer, unless the problem is in the CPUs. Is that very likely? How would I find out if the CPUs are bad?
I've been reading alot about the problems I'm having with this G5 and what I've been having seems to be very common. But I've run out of fixes. Is there anything I can do to fix this machine or is it just money down the drain?

my iMac 20" G5 experience since December 2004, even though I love this machine,it has gone through 3 power supply (661-3350) replacements and 3 logic board replacement since late 2004. Pretty crazy for a single machine but I still love it. The last logic board replacement did NOT fix my boot up problem, as I expected, and the genius finally agreed to replace the power supply and that fixed it. SO: My recommendation to you is "replaced the power supply" here is one place you can get one: http://www.dvwarehouse.com/Power-supply-180W-for-iMac-G5-20--100v-661-3350---614 -0353-----NEW-p-25613.html

Got logic board replaced, same problem! KERNAL PANICS!!!!

I got my logic board replaced about 1 month or so ago, due to a faulty gpu causing kernel panics whenever i played any games or used photoshop or anything that required a gpu or cpu to work hard. Now after waiting a month for the repair, the problem was not resolved. Any ideas??? Can I get it replaced? I noticed that the latop get extremely hot after maybe 10-15 mins of COD4 (too hot to touch) and then the game freezes and crashes or I get a kernel panic.

I forgot to mention that even when just browsing the internet, my temperature goes to around 70c and the fan is extremely loud, shaking the entire laptop and my desk. This also occurs when I play Age of Empires III. I sit next to my friend while he plays Wow and I play cod4, my computer is around 80-90c with the fan around 4000rpm, his is 60-65c with the fan at around 2500-3000rpm. My computer is too hot to touch after just 15 minutes, his is fine after more than an hour, right now, my laptop is at 58c and the fan is at 2000rpm and I can hear it quite well in a noisy room.
Message was edited by: inski94

Did Apple mess up my logic board? (Fan always 4000 rpm!)

So I just had my logic board replaced because I was having sleep/wake problems and I think that problem has resolved, but now I have noticed a new problem. My fan seems to jump directly to 4000 rpm during start up and sits there always despite low activity. I have installed smcFanControl and it is reporting a CPU temp of 39-40 ˚C, so this can't be a normal fan setting at that temperature. I am sure Apple could have messed something up installing my logic board but I was wondering if there was anything else to try to fix this problem before giving them a call. I hate sending this thing in because I really need it for class. Anyway, I have tried an SMC reset and that did not do anything. I will try booting from an external HD to see if that resolves problem (I'm sure it won't). Anyone have advise on what to do? Thanks!

Apparently smcFC was the culprit. I noticed it had a crash log in my console and when I booted from my external my fan was fine. Uninstalled smcFC and the problem has resolved.

Logic Board/Video Card Problem?

I sue Bootcamp with vista. But my Mac OS X isnt working either. heres the Deal.
I use my computer for gaming and its been great but just yesterday, it had a graphical error. The Screen Flashed Black and back on several times before giving m the blue screen.
It says the problem is that the Driver software couldnt load, so i tried to load my Mac OS, it loaded fine at first, once in inside of any webpage, it was choppy, when i loaded ITunes, it stalled and froze. Now it load at it stalls when i select what OS to go into.
I can load Windows fine, but any time i load it out of safe mode i get green dots across my entire screen while it loads, and the Device manager gives me the error code 43 under Display adapter.
Ive never had a problem like this, my computer is out of warrenty. ive tried a ReFromate and no luck. Heres everything ive attempted so far.
I have installed Current Nvidia Drivers.
Ive rolled back to old Nvidia Drivers.
Ive Reformated my Windows Vista Partition(i couldnt reformate my OS because it freezed with Mac OS X installer Cd inserted.)
Im game for any help and support. Ive been hung out to dry by apple and a certified tech said it was logic board problems over the phone and it would be 700$ for repair. Please help!

Hard to say ... the only way to tell will be to exchange parts and see if it's gone and that kind of stuff could be anything ... it could even be the power supply.
One thing you could try is to run Xbench and check which test makes things worse (not that this really gives hard data, more like adding to the indications).
Another thing is to download iStat/Pro or a similar tool and check the temps. Maybe just a fan gave up and something is overheating. Possibly (maybe) that's why you could get into iTunes and later stalled at the OS selection (because the longer you leave the machine on, the worse the heat gets).
This is all wild guesswork though ... and I doubt a tech over the phone could determine the root cause with confidence (not without running a test software). And for $700 you could buy a 2nd hand iMac8,1 on eBay and sell yours as parts.

No serial number after logic board replacement, now problem to upgrade to Lion

Hi, I have a MacPro 3.1
I replaced the logic board 16 month ago and it came back without a Serial Number.
It wasn't a problem a the time so I didn' mind.
Now my mac doesn't want to upgrade over 10.6.2, so not to mac osx lion either.
Any idea of how I can put the serial number back into my mac pro without sending it back for repair? I need it for work...
Sorry for my terrible english.

Logic Board replaced now no Serial...: Apple Support Communities

New Logic Board - now audio problem?

Hi,
My macbook went in for repair the other day, they said it had a faulty logicboard so have inserted a new one. Now my sound seems to be very tinny and not very loud. This is a computer-wide thing so it's the same with itunes, on the net etc.
Is there anything I can do to try and get the audio back to normal or should I get in touch with the guys that repaired it again?
Cheers,
Tom

Yeah that's what I thought. I'll get back in touch with them at the start of next week. At least the machine is staying on now!
Just wondered if there were any settings that could have been altered.

Bad Logic Board. Can I use a MDD?

I have a Powermac G4 Quicksilver 800mhz x 2. I can I use a MDD Logic Board with the Quicksilver processors?

I would not do it. The processor modules for both machines are different designs not to mention the heatsink.
My answer is no.
Are you positive the Logic board is bad? did you run the apple hardware test CD that came with the Quicksilver to confirm it is indeed a bad board?
iBook G4 Mac OS X (10.4.3)

PowerPC G5 not starting up after continuous fan problem

Hi - Ive seen similar problems on the forums but would like to write down my own case in case it varies from others.
Recently, Ive been returning to my mac after periods of leaving it alone to find the fan wizzing continuously and the computer frozen. Ive had to turn it off and on again to get it working. Its done it previously once or twice maybe a couple of years ago, but has started doing it more frequently over the last few weeks.
Anyway.. today it did it again. I immediatlely tried zapping the pram after reading that this may help, but now it doesnt boot at all!
Im getting really stressed as it has all my work on it and I really cant do without it for long
Ive tried zapping the pram again but after holding down the keys the screen just stays black and I dont get another boing.
I did leave it shut down for a while, started back up, after a while it did display my desktop image but then did nothing else
Would anybody know what the problem may be?
many thanks

The G5 is quite an old one (maybe 4 or 5 years) it was the last of the PowerPc versions before the intel came in I think - pretty sure its not water cooled
If it isn't a 2.5GHz or a 2.7GHz machine, then it isn't liquid cooled.
If it is one of those, look for leaks.
For more info on LCS leaks, see my post here:
http://discussions.apple.com/thread.jspa?messageID=9846620&#9846620
haven't tried reseating the RAM however and will give this a try tomorrow when Im back home. I wouldn't know which the graphics card is actually but Im sure I can find out
Instructions here:
http://support.apple.com/kb/HT2580
So do you think some disconnected RAM could actually be the problem? Im getting quite worried about this actually as I cant afford a new computer at the moment :-s
Not so much the RAM, but the slots/logic board.
Remove all your RAM (keep pairs together).
With the original shipping RAM (use only 1 pair) place the two DIMMs in the center two slots.
Try booting.
If still a not booting, move that pair of DIMMs out one slot. Try booting.
If only one pair of slots is affected, leave the affected slots empty. The machine may be returned to service, all be it with less RAM.
If the moving of the RAM does not provide relief, another test for logic board/RAM slot problems, is to heat the logic board around the RAM slots with a hair dryer.
Heat the board until it is toasty warm, then try booting.
If you get the machine to boot during the heating tests, take that opportunity to back up all data.
Don't shut the machine down, though.
Machines with this type of problem may run for days without fail, but the problem is severe, and ultimately means a new logic board, or repair of the logic board by 3rd party.
Either way, the failure is $350-$700+ to repair or replace.
Message was edited by: japamac

My G5 died... new logic board needed... What do i do?

Ok, here's the story:
The other day, my G5 crashed when i wasn't using it (screensaver).
I hard rebooted it, fan started to spin, power light flashed only when i pressed the button and then no screen. After a while, fans started at full speed...
Tried loads of things (reseat memory, PCI cards etc...), nothing worked.
I took it to the local Apple Certified Service centre. They called me after half a day to tell me that the Logic board had a problem and needed replacing and quoted £585 inc vat!
No need to say that i am pretty upset as i paid 1400 3 years ago for that machine!
Now, what are my best options?
This is a dual 1.8 G5 (early 05) with 3Go ram and 2 SATA drives. I have 2 standard Pci Cards for music in it (RME audio card and UAD-1).
Should I get it repaired?
Should i buy a second hand G5 (which would cost the same sort of price but with the risk of having a problem as well)
Should I go for a new or newer Mac pro but can i reuse my memory, PCI cards, disks etc???
Thanks a lot for advice.
Laurent

Hi tek_uk,
Welcome to the forums.
Your mac is one found in either of these model series. Anything you have now on your mac would work for both series and if you chose to go with one of the faster models listed you could easily do that.
http://support.apple.com/kb/SP80
http://support.apple.com/kb/SP67
Replace logic board... There must be a special course at Apple training schools in saying that.

I think my Logic Board has gone POOF!

For anyone who saw my post last week about upgrades to my Digital Audio Power Mac G4, it's now taken a turn for the worse...
A few days ago, after booting my OS 9 HD, i found that i couldn't get any audio from it. The machine would chime on startup but would not make any noise afterwards. Changing the volume, trying the Alert Sounds, selecting Outputs, nothing would make sound...
At first i thought it was a problem with the drive so i backed up everything of import (mostly old games) and wiped/reinstalled OS 9 on the drive. Since then ive not been able to boot the OS 9 drive. Its recognised on the OS X drive as a bootable disk but whenever i try to boot it, it just goes back to booting the OS X drive.
Then this morning, i thought id try the Apple Hardware Test disc that came with the G4 software. After running that it stopped half way through saying there was a problem with the Logic Board . Firstly i tried putting another processor in (i recently swapped out my Sonnet Encore ST 1GHz for a Encore ST 1.4 GHz, the 1GHz came with its own fan and heatsink where the 1.4GHz relies on using the heatsink of the standard processor. I was concerned that the processor might have overheated and cause some big problem!) But that made no difference. After a few attempts at it the computer now will not boot at all. Power goes to it (the main fan starts up, the CPU fan attached to the heatsink starts up, and the red light on the Logic Board comes on) but it won't chime or do anything else, the Hardware Test disc is still in the optical drive too!
The only thing i can think of at this stage is the Logic Board since the problems have gradually gotten worse, starting with lack of audio then progressing to not working at all...
Anyone got any knowledge or thoughts that might help me?
Cheers!

it is a bit, but i cant say anything more than what AHT tells me...
the original code was something like ERROR_CODE>>>>>>>ERROR_CODE>>>>scc_/3/7 or something like that, it didn't really make it clear...
BUT i ran the test yesturday on the system and it now seems to have sorted itself out. I ran the extended test twice and both times it said there was nothing wrong with the system! Very Odd!
So that problem seems to be sorted, but the OS 9 one remains...
I gave it another go yesturday too with the install. I checked the drive by trying to boot the OS X Tiger retail disc that i have, that booted up fine, so its clearly not the optical drives that are the problem. The computer just wont boot the OS 9 disc. I tried the disc in a few other machines (a Beige PM G3, a PowerBook G3 and an iBook G3) all of these machines can boot from the disc, so i dont see how it could be the disc either.
I also discovered that DA Power Macs are only compatible with 9.2.1 or higher, so i initially thought "ahh that might be why its not working, the version of 9 ive got on the HD is 9.0.4!" so i ran the rest of the updates to bring it up to 9.2.2. Alas it didn't make a shred of difference . Ive tried re-blessing the System Folder, unplugging the OS X drive so the OS 9 one is the only visible drive. Each time i do it just loads up with the smiley folder/question mark icon that normally means it cant find a System Folder...
What im trying now is running a full install/update to 9.2.2 on the Beige G3 and, if that works, swap the drives around to see if itll boot that HD.
Its all OS 9 problems from hereonin it seems...

RAM & Logic Board Replaced Multiple Times, Still Beeping 3 Times

Hello! I am new to this community, so I apologize if I am posting in the wrong area.
To begin, I purchased my macbook pro in July of 2011. It has been running perfect until about a month ago. I was on safari, and it froze and began beeping 3 times. I restarted it several times and the same thing happened over and over again. After calling Apple support, I realized it was a RAM issue. So, I decided before I took it to Apple, I would puchase 8 gb of RAM to upgrade from the 4 it currently had. I bought 2 sticks of 4 gb memory and Appke installed it. It worked for a weekend, and on Sunday night I turned my computer off for the first time. When I turned it on, the beeping and freezing returned. Next, I took it back to Apple a few days later and ordered Crucial memory (2 sticks of 4 gb). I took it in and Apple decided that the Logic Board was the problem also... So, they replaced the logic board, and installed the new Crucial RAM. It worked for 2 weeks, and then I turned it off (not for the first time since having the new logic board and crucial RAM) and it began beeping and froze the next time I turned it on. Took it back to Apple, and they are telling me it is the Crucial RAM and that they are bad sticks, although it worked fine for 2 weeks with that RAM. My questions are:
Should I just take it back with original memory and let them replace it back to 4 gb (2 sticks of 2 gb)?
What else could be causing all of this?
I also noticed, in two weeks it was working, that it would get very hot and the fans would be going full force. All I had open at the time: Netflix on Safari and finder.
I am begging for help, this has been a nightmare.
Thanks so much!!

What happens when you install the original RAM?
(I am surprised that Apple was willing to install the RAM modules you purchased. Usually one has to buy RAM from them in order to have them install it.)
MmB2 wrote:
I also noticed, in two weeks it was working, that it would get very hot and the fans would be going full force. All I had open at the time: Netflix on Safari and finder.
Reset the SMC:
http://support.apple.com/kb/ht3964
If there is no change, Post an image of Activity Monitor set to ALL PROCESSES and % CPU to display values from high to low.
Ciao.

The ultimate G5 fan problem: CPU Intake Fan speed error

Another saga of fan overdrive blowing. I have a Power Mac G5 Dual 2.0Ghz, about 3 years old. About 1 year ago, had fan blowing after sleep problems (fans blow super hard, cannot wake from sleep). Eventually resolved this with Apple Care by near-total hardware replacement: fan replacement, fan sensor replacement, case replacement, finally logic board replacement. Problem fixed for 1 year.
Recently problem started again. Now, the fans blow full speed all the time, from the moment of boot (before OS loads). At first, resetting NVRAM from Open Firmware fixed the problem, but after a day or two it would start again. Now, nothing works - although if i manually put computer to sleep, the fans do turn off, and computer does wake up, which is nice.
I have tried the following well-known fixes, none of which has worked:
- Repaired Disk Permissions from boot CD
- Set Processor Performance to Highest
- Trashed Energy Saver prefs
- Removed all peripherals
- Removed RAM
- Took out hard drives
- Reset PRAM
- Reset NVRAM (from Open Firmware)
- Reset PMU (motherboard button)
- Replaced PRAM battery
- Checked inner (clear plexi) door sensor
- Cleaned out dust from inside case
- Check temperatures, all i think within normal range (<40 degrees (c), except GPU which is 65)
- Reinstalled OS X (archive)
Finally I obtained the legendary Apple Service Diagnostic disc.
- Ran Apple Service Diagnostic
- all hardware passed
- Ran ASD fan calibration
- "Error CPU0: CPU intake fan speed error. Check that inner door is secure and in place."
The inner door is indeed in place, and as far as I can tell the sensor is working since the indicator red LED on the logic board turns on and off when you remove the door. Is there another way to check that sensor?
What else can I try? I've spent about 40 hours on this so far... The only thing I have not done is take out and reseat the CPU's, but as far as i can tell the only reason to do that is to force older versions of ASD to allow temperature calibration - but ASD v2.5.8 fixes that.

I am having the same problem with a dual 2GHz G5. It runs fine, all temperatures look normal (in the 30-40 degree range), but all the fans are stuck on full.
There's a bit of history here: I used this machine for a while and intermittently it would completely freeze and the fans would increase to full speed (presumably to prevent damage to the components). This was never fixed because it happened only about once a month. Then, all of a sudden, it failed to start up completely. I figured it was a bad logic board. So now I have swapped the logic board, resulting in the computer seeming working fine apart from the full fan speed.
I read that the reason for this is that it needs a thermal recalibration. So I ran the Apple Service Diagnostic disk version 2.5.8 and it does indeed report that the CPUs require calibration. Unfortunately about 10 minutes after starting the calibration it reports "Error CPU0: CPU intake fan speed error. Check that inner door is secure and in place." The inner door is indeed secure and in place and indeed the red LED does come on if the inner door is removed, proving that the sensor is working properly.
e.f. - if you have any luck with the things that you are trying please post back here.

Fan Problem: 2 FAN/4/8: Fan for BACKSIDE

Hi,
I ran AHT Test and found following error:
*Error Code*Error Code*
2 FAN/4/8: Fan for BACKSIDE
I don't know the exact meaning and how can i solve this problem.
I appreciate if you guys help me out.
Thanks
Mac G5 Mac OS X (10.4.9)
Mac G5 Mac OS X (10.4.9)

Hi. It may be worth checking which version of the AHT you are using, in view of this
http://docs.info.apple.com/article.html?artnum=86492
It may be a bit tricky to carry out a visual inspection of the Main Logic Board Backside Fan - as it's the one at 90deg to all the others, in a grey plastic housing behind the hard drives.
You could try running Hardware Monitor
http://www.bresink.com/osx/HardwareMonitor.html
On this 'Original' DP 2 G5, the Main Logic Board Backside temp is 43.5C/110.3F, and the Main Logic Board Backside Fan is at 20%. However, note that on the "Original" G5s(before June 2004), OS X, and therefore Hardware Monitor, only reports the fan speed instructions being sent to the fans, not the actual fan speed.
If you have AHT 2.1 (the version should be on the system disc DVD that you ran it from) and you still have AppleCare, you can ask them for an updated version. Even if you don't still have AppleCare, it would be worth pointing out to them the problems this is causing you - and the distress...
If you have a more recent AHT - then it looks like a case for Applecare anyway - or the repair shop. Good Luck.

G4 MDD Logic Board or fan problem ?

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