Power Mac G5 logic board failure?
#463
Posted 21 February 2009 - 11:23 AM
I can't figure out how to do simple quotes without quoting the entire reply.
I end up with a huge mess that I can't make sense of.
I just want to quote specific comments.
Like you do on UBB boards with simple quote tags.
The board software here isn't very intuitive.
Even when I quote the whole message, it's difficult to know who said what.
#464
Posted 21 February 2009 - 01:33 PM
ojsosa said:
IC's can run hot for a very long time if they are monitored and maintained w/in their limits. Heating up of an IC to the point that solder melts (especially lead-free solder) would be very difficult to do w/out permanent damage to the IC.
When you say-"IC", do you mean "Integrated Chip"?
I don't think you're supposed to completely melt the solder, just get it hot enough so it can smooth out the micro-cracks.
In that IBM technote it shows cross sections of the ball contacts with and without the use of the underfill after having been stressed by thermal cycling.
That polymer underfill encapsulates the ball array, preventing fatigue when one of those flexes occurs.
The spring mechanism aids in this by putting pressure on the chip.
An excerpt from the technote:
The BGA reliability evaluation effort focused on
characterizing the impact of the applied compressive load on
the solder ball grid array (BGA) connections between the
PowerPC 970 module and G5 system processor card,
improving the mechanical integrity of the CBGA array, and
mitigating long term reliability risk due to creep and cyclic
fatigue.
So yeah, it doesn't dissipate the heat.
It reinforces the BGA integrity to help prevent fatigue from constant thermal cycling.
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There has to be a way to isolate the specific parts of the board that need reflow.
Wrap the whole board with tinfoil, mark the areas to be exposed, remove the foil and cut out the areas you marked.
Put some sort of insulation material over the board and then put the foil back on top of that.
Bring the temp of the whole board down to freezing.
Then take your heat gun and heat up the exposed areas properly for reflow.
The insulated foil will protect the rest of the board from direct heat, freezing the board will slow the heat propogation and buy you the time you need to bring the exposed area up to reflow temp without effecting the rest of the board.
It would be helpful to know what the thermal coefficient is for the wafer and solder, and at what temp the 2 materials begin to change state.
What worries me about doing the reflow on my own is that it seems that the silicon wafer would have a much lower thermal tolerance than the solder.
So by the time reflow temps are reached, the silicon wafer has already changed state and started to break down.
-----
I used to work for a local company that supported local NT business networks and ISP's.
We were constantly replacing hardware for 2 architecture firms that had small net render farms for FormZ and Lightwave.
The majority of the issues aside from regular hardware/software upgrades were bad RAM, RAID disks, GPU failures, license server and dongle issues(dongles are a b1tch).
I worked there probably 4-5 years and in that time I never saw a logic board problem like apple products are always having, and never even heard of reflowing the solder on the board.
Boards sometimes needed replacement, but it was never anything like with the apple boards.
All the boards in those archviz workstations were either Asus or Iwill.
Mainly P4 and Xeon single CPU configs.
Also, I've been watching alot of youtube clips on different ways to do a reflow, and they're all apple machines(many G4 iBooks) and 360's(some cell phones and portable devices too).
So is there some reason that PC mother boards aren't effected by this?
Are apples boards just really poor quality?
Or are they that much more complex and specialized than PC boards, which makes any problem with them a big mess?
Could be that during my time with that company, CPU speeds weren't fast enough to generate heat levels like we have now.
That was back in 1999-2003/4, and clock speeds maxed out at like 1.6GHz P4's/2GHz Xeon's before I left that job.
#465
Posted 21 February 2009 - 04:45 PM
glaston said:
I don't think you're supposed to completely melt the solder, just get it hot enough so it can smooth out the micro-cracks.
That's correct, the solder is actually 2 kinds, on the chip and the board it is a silicon-lead mix, but the ball is mainly lead. The ball melts at a slightly higher temp, so it gets stuck to the chip in an temp controlled oven. Then the process is repeated to attach the chip to the board or they use IR soldering. The ball needs to stay intact to account for the expansion & contraction when the chip is in use. The ball needs to be strong enough to take the heat sinks compressive load, even when the chip is heated under use. You can see the 'fillets' of the silicon-lead solder around the ball in the tech note.
The problem is that reflowing on the board might not do much good, the solder will have no flux & is probably contaminated with dust. The temps need to maintained for minutes, and raised and lowered in a controlled manner to get a strong, but flexible joint. It may be that the joint is damaged where it meets the chip, so softening the solder may move the ball away from the chip. Too much heat will probably collapse the chip into a big mess of solder.
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Wrap the whole board with tinfoil, mark the areas to be exposed, remove the foil and cut out the areas you marked.
Put some sort of insulation material over the board and then put the foil back on top of that.
Bring the temp of the whole board down to freezing.
Take care - most domestic freezers are full of ice & water vapor from the air. There is enough moisture in the air to condense on the components, turning to steam when the heating begins. The reballing literature I have seen suggests the whole board should actually be pre warmed to limit the warping effects of heating a local area and to dry any moisture on it.
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The insulated foil will protect the rest of the board from direct heat, freezing the board will slow the heat propogation and buy you the time you need to bring the exposed area up to reflow temp without effecting the rest of the board.
It would be helpful to know what the thermal coefficient is for the wafer and solder, and at what temp the 2 materials begin to change state.
I think I read the reflowing occurs around 200-220?C, but it may have not been specific to the G5 & it's lead based solder. There seems to be standardized reflow oven profiles for specific solder types. It isn't clear to me if the later G5 models used lead free solder or not. I have no idea when Apple started phasing it out for RoHS. Wikipedia suggests lead free became prohibited around 2006 for the EU, with the US dragging it's feet along with China.
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So is there some reason that PC mother boards aren't effected by this?
Are apples boards just really poor quality?
PC users don't have Firewire or iMovie so they can't record videos for youtube :) jk
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I suspect it is partly because Apple likes to try to engineer it's way out of a corner. It uses high quality materials & design (boy these G5 cases are sturdy) to try to push limits, sometimes it gets bitten. Microsoft got bitten too, the 360 can fail for this reason (among others).
#466
Posted 22 February 2009 - 04:57 AM
www.activehome.co.uk/computeractive/features/2014044/know-consumer-rights-part-basics
[http://www.pcpro.co.uk/news/202227/why-pc-warranties-are-increasingly-worthless-.html?searchString=pc]
"The good news is that the Sales
of Goods Act applies for up to six years after the sale, but it's
undermined by the fact that it only covers items that have failed to
last a "reasonable period", whatever that might be. How long should a
computer last? How long is a piece of string?"
Obviously, Apple will hide behind the fact that 3 or 4 years might be deemed a reasonable life expectancy for a computer. Although, when i spoke to them i asked them to confirm that a G5 wasn't supposed to work longer than 4 years and obviously they declined to comment. They customer service rep even told me that i was lucky that my mac ran for almost 4 years without a repair!
I suspect they can claim that 4 years is reasonable for isolated incidents but when you have mass failures then it probably no longer holds.
A lawyer friend of mine also told me that the fact they repaired some units for free but refused for others (apparently depending on who you talked to) might be considered discrimination! hence i'd be useful to have the case numbers of those who have had thei macs repaired for free.
Just a few thoughts.
#467
Posted 22 February 2009 - 06:05 PM
Seems like there is some kind of Consumer Protection organization or act or similar in the US? Does that ring any bells?
#468
Posted 23 February 2009 - 02:08 PM
#469
Posted 23 February 2009 - 07:25 PM
http://www.consumerwebwatch.org/
There may be a way to get our problems published in this blog:
http://blogs.consume...rg/electronics/
h2. About this blog
Consumer Reports' electronics reporters, editors, and testers will
quickly report on new developments and trends.
#470
Posted 24 February 2009 - 02:04 PM
I want apple to pay for repairs or replace my machine.
That's it.
Due to this event, I've had to turn down 2 freelance jobs because I'd rather turn them down than have my machine fail completely at some point in the job when the client can't get someone else to complete it before the deadline.
I'm just a student that does freelance work to make ends meet.
What's worse is that replacing this machine out of my own pocket will incur other costs I can't cover.
If I bought a new intel mac, I'd have to buy the latest version of cinema4D and After Effects to get the UB.
If I buy a PC, then I have to replace ALL my design apps
So that's an additional $2000+.
I could get the student version, but then I'd have to upgrade it next year to the commercial version to legally make money using it.
So if I can't get this machine fixed for free or low cost so it lasts me through school, I'm screwed.
I bought this machine with the specific purpose of getting me through school.
It's why I didn't save some money and get an iMac or macbook.
#471
Posted 24 February 2009 - 03:13 PM
For this issue with the G5's, what we'd probably end up having to do is have the problem examined by a 3rd party.
IMO, that IBM technote lays the basis out for that .
The G5 chip was known to generate alot of heat, one of the effects of this was that the life of the G5 was drastically reduced.
To cope with that, the "underfill" and spring mechanism was added.
Normal soldering methods were insufficient.
What they did was basically glue the chip to the board and apply constant pressure on the chip, in addition to the standard reflow solder methods.
Product life expectancy was the problem that they had to overcome in development, and it's the substance of our claim.
#472
Posted 28 February 2009 - 08:56 AM
While I haven't put my G5 together yet to see that all is well after picking up my G5 last night (doing so in a few hours), I am at this point, feeling darn lucky.
One thing that may seem petty to some. I treat all my computers with kit gloves. When I left it at the Syracuse Apple store it's case was like it was brand new. When I picked it up, the case had several scratches on it and was filthy as if some ate their lunch on it. I won't be bringing any other of my issues to that store!
#473
Posted 02 March 2009 - 09:54 AM
Dual 2.3GHz G5
Serial: CK52602.... Early 2005 model
Mine stopped booting about a week ago. You could just hear the
hard drive spin up and the fans come on but it very rarely got any
further. If you left it switched on the fans would start racing up to
an alarming speed. On the odd occurance that it did start up, it would
freeze within a couple of minutes of use and then would not boot again
after a restart. So it sounds like exactly the same symptopms that
everyone else on here is experiencing.
I took it to the apple "genius bar" yesterday and was told it was down
to either the power supply or the logic board. They quoted me £64+vat
for a new power supply and £430+vat for a new logic board, with of
course the £69 labour charge.
I explained that I had been researching the problem and it seems to be
becoming fairly common that dual processor G5s are dying of logic board
failure at around 3.5 years old and their basic response was, "That may
be but there are alot more that aren't"
I then explained that I thought a 3.5 year lifespan of a £2000 computer
didn't really seem reasonable to which they didn't really give a reply.
So I am just waiting for a call to let me know what the actual problem
has been narrowed down to, no prizes for guessing they are probably
going to tell me it's the logic board.
I've looked after my mac and it has only been used for sound and music work, which is my business. I have pc's which have been abused and had everything thrown at them and are still functioning six years down the line, which carried a fraction of the G5's pricetag.
I am in the UK, so today I went to the citizens advice bureau to see if they could shed any light on the grey areas of the consumer laws which would apply to this situation. Bascially as I think has been mentioned previously, in the UK, the Sales of Goods Act applies for up to six years after any purchase. Under this goods have to be fit for purpose and be of a satisfactory quality which includes meeting the standards that any reasonable person would expect with regards to durability and being free of defects. The bad news is that if a product is over six months old it is the customers responsibility to prove that the product possessed a fault from the date of purchase which has affected the durability.
I was basically advised to argue the fact that my G5 hasn't been as durable as reasonably expected when purchased, and that it may have had a defect from new. However the latter relies on either finding enough similar cases or having an independant review comissioned. This all his has previously been brought up.
I'm not too hopeful about getting this done for free, apple seems to be refusing any knowledge of multiple G5's dying of exactly the same thing at around the same lifespan. It seems those who have had it fixed for free, did so down to mistakes being made in apples customer care procedures or through customers having had a long buying history with apple. I will give it a try tough, because I can't help but feel ripped off by a. the limited lifespan of such an expensive machine and b. the rediculously overpriced repair costs.
I will report back if I have any success in dealing with apple. If I don't I will have to pay the bill because I need the machine for work and I'm already being held back by not having it. However I will consider putting in a formal complaint with apple as well as getting in touch with the likes of Watchdog and some other consumer rights organisations in the UK.
#474
Posted 02 March 2009 - 10:50 AM
I mentioned it before, but since there have been soooo many posts on this topic I'll mention it again.
I had to run the Apple HW Test Tool (comes w/ your installation DVD/CD's) many many many many many times (at least 40x) before it recognized bad video ram. And I'm talking about the "extended HW test" which runs ~3hrs on my machine.
If any of you with these reports of "bad logic boards" from the Genius Bar (that's the same thing they told me) are unconvinced... I suggest you buy or borrow a compatible video card and try it out.
I used to have the Nvidea card, top of the line... what a waste!
Good luck,
#475
Posted 03 March 2009 - 11:34 AM
I'll admit upfront I'm a hardware dummy, so please forgive me for asking things that are going to be blindingly obvious to you gurus. But I want to be sure I understand all this tech stuff in case it helps me with my issue, because the Genius Bar are not gonna believe me when I tell them stuff like this!
The video card is attached to the logic board, so replacing the logic board is thereby replacing the video card, and that's how some people's machines are then working?
Are any of you who are finding it's the video card using an iMac G5?
My iMac G5 won't even boot up so is it still possibly the video card? I know video card problems would mean I wouldn't see anything on the screen, but would that also mean no sound? Meaning even if the video card is the only problem, the machine takes that to mean the whole logic board is bad and won't boot up? I'll have to get the Genius Bar guys to look at the logic board for any obvious physical signs of problems like the blown capacitors mentioned earlier, and if there are none of that then is it worth it for me to pay them to run that "extended hardware test" a bunch of times for ~3 hours each time? I can't imagine how much that's going to cost. Or can I still accomplish that? Will my machine actually start booting and reading from my system disk I put in the DVD drive if a bad video card is the only problem?
I also had to replace the power supply a few weeks before this logic board/video card issue. This has been my first purchase of an Apple product and it will be my last. I feel sorry for you guys who are stuck with them because you've got so much software and peripherals that are Apple-specific. It seems that buying stuff from a company who is the ONLY one making the products ends up giving them a sort of mini-monopoly and an advantage that hurts us in situations like this.
#476
Posted 03 March 2009 - 12:11 PM
macbabe said:
The video card is attached, but is not usually permanent, Power Macs/ Mac Pros can have the card replaced, it may be the case with iMacs, but I suspect the case design means that the card needs to be a specific type, possible a laptop design. Upgrading the video card on a Power Mac is a user installable part eg. pretty simple. The logic board can be replaced and the old graphics card can be reused, it keeps the repair costs down.
>I'll have to get the Genius Bar guys to look at the logic board for any obvious physical signs of problems like the blown capacitors mentioned earlier, and if there are none of that then is it worth it for me to pay them to run that "extended hardware test" a bunch of times for ~3 hours each time? I can't imagine how much that's going to cost. Or can I still accomplish that? Will my machine actually start booting and reading from my system disk I put in the DVD drive if a bad video card is the only problem?
You could try inserting the system disk that came with the iMac & hold option on startup (the disk should have Apple Hardware Test written on it in tiny letters somewhere). Then select the apple hardware test option. If it boots into the test, you can run the extended test as Ojosa mentioned.
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You should tell the Genius about the history, maybe they will do something for you if it is related.
I also think you could open the iMac to look for the expanded capacitors if you were so inclined, there is 2 screws that allow the back to open IIRC, Apple list info for doing basic upgrades on their support site. I'm sure you have seen the images on other sites talking about the capacitors.
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