# Help! Can ALL Dual G5's startup on ONE processor?



## Windsong (Oct 16, 2009)

I have G5 2004 that won't startup.
I have heard conflicting reports about the G5 being able to startup with only one processor in the upper socket.. to test which processor went bad.
Some say yes, some say not all can startup with only one processor seated.

*Mine won't.*
As soon as I put the suspected "bad processor B" back in the slot or even swap A for B, I get a startup tone & attempted startup.

But (it doesn't matter which)* with one processor in the upper slot only 
Pressing the power button results in nothing at all.*

So am I wrong?
Some can not start without both CPUs being seated?

Or is this a symptom of a bad motherboard?


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## DeltaMac (Oct 16, 2009)

If I read your other posts correctly, you have a dual 2.0 GHz (2004) G5, which, according to Apple's service information - will NOT boot with only a single processor installed. Only the dual-1.8 Ghz from that model series, or older models of the dual G5 will boot with a single processor installed. You don't have the right system to troubleshoot with that technique, so it doesn't indicate a bad logic board.


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## Windsong (Oct 16, 2009)

Oh man is that good news.
Thought I was going nuts. Every third person I asked said you could. 
But the reaction of the machine "felt" like it was simply waiting for something to be seated in the lower processor socket. 
I did try separately Both A & B in the upper & not even a teeny response from pressing the power button. Then add Either of the two and it power begins.

When A (suspected ok) is in upper position the fans behave "normally".
When B (suspected bad) is in the upper position fans run full blast which is exactly what I was told by DJ. 
Then return them to their original positions returns the fan behavior to normal.
Still no startup, but normal speeds.

So depending in price if I can find a matched set of processors should any 2.0 processors work? ( I know about the recalibration)
Or do I have to get real specific in buying a matched pair?

I already know that I *do* if I'm trying to replace just one CPU. It must have the same EEE numbers as mine. Still don't know what EEE numbers are, but I have seen sets with close numbers, but not the same exact numbers.  

And yes, Mine is June 2004 with PCI-X slots. 
To work do I have to find a single processor with RDYB? (apparently the relevent part of the number string on the processor)


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## Windsong (Oct 16, 2009)

I've got a seller who has two matched sets that he will offer a deal on.
They do not match my RDYB code, but he says they are from early and/or possibly late 2005 machines.
He's going to get me the numbers.

Any way (a resource, or post to one of you geniuses::angel: 
to check if the numbers he sends me correspond to processors that are compatible with my June 2004 A1047? 

In this case* I would be buying a matched set*. Double double thanks.
Tom


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## DeltaMac (Oct 16, 2009)

The early 2005 2 GHz processor will only work in the early 2005 logic board, which has PCI slots, and not PCI-X
The late 2005 2 GHz processor is completely different, the logic board is PCI-E slots.
Processors and logic boards between the different generations are not interchangeable, and the processors need to be matched up (that's the EEE code mentioned, which is the last 3 characters of the part's serial number. (actually it's the last 4 without the final character, thus xxxxxxEGP4, would have an EEE code of EGP.
You would get processors with any of these EEE codes:
R06, R2R, R2S, R2T, R2U, RDV, RDW, RDX, RDY, RDZ, RG8 or RQ9.
I DON"T know for sure if the EEE code has to be the same on both in one system. I think you could take your chances with that. Apple's service manual does not say anything about that. I think you will be OK with any EEE code in that series.

You'll notice that one of those is RDY, which would relate to the RDYB that you mentioned. Note that you drop the last character, so you get the RDY.


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## Windsong (Oct 17, 2009)

Wowzer!
Thanks. I was about to correct you, but thinking better of it, I thought I'd check mactracker first, & sure enough, the 2005 2.0 had good ole PCI slots!
*HOW* did I miss that???... duh...

I suppose I assumed that the late 2004 models were the last of the PCI slots... *progress* and all.

*This is, in fact good news to me*, since I have a "MOTU" music interface with a breakout box and a PCI card that I was* terrified *to try in the PCI-X slots that my kinda sorta not working A1047 "June 2004" G5 has. 

I've read everything I could online, but *noone *seems to know if the card will work *or fry.*
Which is why I've been all over the board seeking advice on repairing my MDD dual 1.25...
Which I know it's safe to use that system in.

Now that cost -wise, it looks like my best bet is to get *ANOTHER G5*...PCI this time.... and if I can find a single, or a couple of... processors for mine.. I'll probably just sell it.

I can NOW *also* look for an Early 2005 2.0 *with PCI slots.* 
I've had my heart set on 2.0Ghz minimum, but failing that there are a lot of dual 1.6's & 1.8's out there for sale and many have PCI.

I never did understand why with Mac, there were all these different protocols *at the same time...*
Wikipedia just tells you what they are, not really WHY PCI-X came and went so quickly....There were three different slot configurations going on all at the same time. 
*With PCIe I understand the reasoning totally. It's way faster... better.*

I suppose in the march to PCIe, there was PCI "plus" which turned out to be PCI-X,* and I wish I'd never gotten the machine I got.*

MOTU doesn't answer the phone or emails ... they're in a world of doo doo about their recent disaster of a music interface product. 
So I couldn't as they always say... "contact the card manufacturer" to make sure it can handle yadah watts & volts etc. from the PCI-X slots.

Thank you SOOOOO much for the list. 
*Where did you get such a list of compatible part numbers?*
Some auctions print such lists.
Others say nothing at all, and I'm left wondering if it's the right machine or CPU or not.

Can you "share... where"? 
It'd make my life (train wreck right now, borrowing my wife's sawtooth) a ton easier in my search to get recording again.
Thanks so much!


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## DeltaMac (Oct 17, 2009)

I don't think that your MOTU PCI card will be 'fried' by trying in a PCI-X bus. It may be compatible - no, should be compatible, as PCI-X is designed to be compatible with PCI cards. It would simply clock down the bus to the speed of the slowest PCI card.
BUT, some older PCI cards just aren't compatible with a PCI-X bus, and simply won't work if you try it out.
I don't agree with your impression that PCI-X came and went very quickly. It first appeared in PC systems in 1999, and moved into history in 2004, even though the PCI-X 2.0 protocol was approved in 2003, and PCI-X 3.0 protocol is also there. Few manufacturers jumped to that, because (as you already know), the older PCI protocols have been superseded by PCI-Express - which is much higher performance. 
Technology marches on, eh?

I think I found that information about processor part numbers in Apple's service manual for the PowerMac G5 - but I can't share that with you.

My thought about finding a newer dual 2.0 GHz with the PCI bus? Yes, that might be OK, but the newer systems also requires newer versions of OS X, and a really old card might not have driver support in the later OS X system software, even though the hardware is compatible. I can't prove that assertion, but it's something that you should also be prepared for.


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## Windsong (Oct 17, 2009)

Again, a wealth of information.
This, from my G5 service manual was what mad me nervous...
_"*The PCI slots can accommodate mixed-voltage (5.0 V, 12 V, or 3.3 V) cards but only at
3.3 V signaling (huh?), with 32-bit or 64-bit data widths and a 33 MHz frequency. You can add a
66 MHz card to a 33 MHz PCI slot if the card can operate at the lower 33 MHz rate.

Warning: Do not use PCI cards that function only at 66 MHz in the PCI slots. Damage to
the equipment could result. If you are installing an additional 66 MHz PCI card, rather than
replacing an existing PCI card like-for-like, check with the cards manufacturer to see if the
new 66 MHz card_ also works at 33 MHz."

Can I safely "assume" that my circa 1999 PCI card can or probably does operate at 33mhz? *THAT* was the concern.

Also looking through my service manual more deeply I saw a list of symptoms & what they might mean.

Here's what happened: 
Initially, the computer ran normally. Then Sys profiler started showing that I had one processor, and processor B was grayed out. Activity monitor showed only one window of "processor usage bars" when there were always two. Finally, the computer would not boot. 
My *assumption* (which I now question) was that processor B failed, but looking at the list of symptoms, the computer *should* be able to startup on processor A alone correct? Even if Proc B was bad, swapping them (which I did) it still failed to show video, hard to tell if it actually booted.. I get a chime, hear disk activity for about 30 seconds after pressing power button, then the fans slow down & activity slows. Every few minutes I hear "some" disk activity, but have no idea what that means. 
To the touch, heat from the upper processor is _slightly_ higher than the lower processor. Could that mean that proc B is not getting proper power (or signal etc) from the motherboard? 

Ram check led shows ok RAM. 
Does this mean I may actually have a motherboard that died & that processor B might in fact, be ok?

*Logically, if a single processor (B) dies, shouldn't my system still boot with one processor as long as Proc B is still seated?
*
If that's the case then wouldn't  the motherboard be the suspect?
I did get a new graphics card because the one that came with the computer was showing  digital hash on the screen after about 15 minutes of operation. 

I *have* no video card to swap to see if the new video card itself is bad. the fans spin, but that's as far as I know how to go to test. 
Can I verify that the "new" card is not bad simply by pulling the card and seeing if I "hear" the system boot? Remember, I am currently getting no video at all.

The list of symptoms from the manual that most closely matches mine is:

_No video (LED on, fans spin, boot tone, no video)
1. Reseat video card
2. Replace video card
3. Replace front panel board cable
4. Replace speaker
5. Replace front panel board
6. Replace logic board _ 
Why would the front panel board (or cable) prevent booting when the power button & led works just fine? I did everything else on the list except replace the video card & replace the motherboard? 
Tom


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## DeltaMac (Oct 17, 2009)

About the 66MHz PCI question: If you have used your card in another older Mac, that would have a 33 MHz PCI slot, so if you were lucky enough to find a 66 MHz (only) PCI card, that would not have worked in that older system, either.

The upper processor will naturally be somewhat warmer than the lower one (heat rises, eh?). In actual measurement, the two processors are never the same temperature.
On your RED question: Depends on how the processor would fail. If one processor has failed in a way so the system only sees one processor, then the system won't work. Can't work with just one processor installed, right? Swapping the processors between positions may not have any effect. But, that doesn't guarantee that you have a bad processor. The logic board MIGHT have failed. Hard to tell if you don't have known-good parts to try.
Your easiest route is to locate a similar complete (working) system on eBay, or Craig's List, or whatever.
A list of possible fixes, is just that - possible fixes. You may get to the first item with a fix, or finish the list with no fix yet (but that would be unusual, I think!)

One more thing - POST lights really don't tell you that the memory is good - only that it passed the POST. You should check with a single pair of known-good RAM (and installed in the proper inside pair of slots - the service manual will help you determine how to install that properly)


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## Windsong (Oct 17, 2009)

OK, but as I described events above.... 
First, the running system just suddenly showed one processor. 
Then it restarted ok still showing one processor. 
Then I found it running with fans going all full blast. It may have restarted once after that (can't remember), but then...

*Then it never started up properly again. *

So unless the processor was diiiiii-eeeeee-iiiing slowly,
wouldn't this tend to point to a bad motherboard?

And yes, I'm resigned to finding a sister system, buying it, and using mine as a "parts pooder", especially now that many of my semi-unfounded fears about PCI-X have been dispelled...Thanks for that btw

I can run those cards that have to *have to* on my MDD which I'm also repairing. 
They both hit the wall within 3 weeks of each other. ah life....

On that subject, I see a MDD 1.0Ghz dual processor for a really good price. I just bought a new 1.25 processor (& motherboard) .  
Aren't the G4 MDD's more forgiving in swapping out processors, (save the firewire 800 model). I'd like to have my 1.25 speed back.

I've learned more from you than I can ever tell ya...
This is *really* (considering my non-budget) saving my butt, having to replace TWO machines at the same time!


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## DeltaMac (Oct 17, 2009)

Well, yes, the motherboard might be failing, unless you have a bad processor...
This would run around in circles, unless you have a good set of processors to try, there's not much more you can do with that G5.

G4 PowerMac processors are not separated into two, they're always on the same card.
So, swapping out on a G4, means replacing the set - they're just on one card.


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## Windsong (Oct 18, 2009)

re" swapping MDD's
yes I know the deal. I've done it. I didn't phrase the question correctly. To me, you seemed to be saying, that finding a replacement processor for the G5 meant getting one from the *exact same family. Same year same group of compatible motherboard "codes"* that you listed. 

With the MDD G4's, I was asking if I could use a motherboard from another MDD that had say, a dual 1.0 ghz processor (my _"possibly bad"_ motherboard has a dual 1.25). I can't do that test because I know my PSU to be bad. Since a PSU and a complete computer are about $50 difference, I figured I'd just get another working system, and cannibalize as needed down the road.

I've been told here and elsewhere, that as long as it's not the firewire 800 (which they *seemed* to be saying had a different motherboard), I'd be ok with pretty much *any* dual MDD processor on *any* MDD motherboard, whether they came from the same machine or not.

It was regarding the cross-compatibility, if you will, of the MDD line as far as swapping processors & motherboards... that the MDD motherboards could pretty much handle and "converse" with... 
 the dual 867 
 the dual 1.0 
 Or the dual 1.25 processors  .....without issue. 

As far as the G5 cycle of what caused what, I understand... which is why my "smart choice" (I think), is to find another A1047 M9455LL/A (dual 2.0 GHZ) machine and use it if it's all good, and keep my machine for PSU replacement, fan swaps, buttons, even processor swaps if needed down the road (I know I'd have to run the calibration program if I had to do that).
I know at least ONE of my processors is good (the other may be good as well), even the motherboard may be good.
*I just can't tell any of that until I get a "sister machine". *

I can do this as long as I find the above model and the Machine ID says Powermac7,3
Is this true? 

Or do I have to, with *THAT* group, locate a machine with the exact same motherboard numbers, or... put another way... 
Were there *multiple non-compatible* motherboards within the above  model run?


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## Windsong (Oct 21, 2009)

Update,
Just bought as close to a sister machine as I could determine.. won't really know till it's here & I check the Processor EEE codes.

But I will do some testing.
I like to know what the answer to my story is.
And also maybe finally be able to post something that helps others who are trying to trouble shoot th same type of issues....

Will post update as soon as I can.
Tom


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