Replacement Motherboard for Dual 1ghz MDD G4

That depends if you are keeping the processors, or if the replacement board will come with processors.

There was a fabrication date, from when the processors changed too. I can dig out details, or you could try Google / xlr8yourmac.

Yeah,

what you need to find out is the fabrication number.

This is on the logic board at the end of the final PCI card slot. It'll be something like 820-1308-A, just under where it says APPLE COMPUTER INC.

Basically, if your current board is 820-1308-x, 820-1440-x or 820-1445-x, you need to replace it with a board from the same fabrication (if you're going to re-use your existing processors). Otherwise make sure your replacement board is not one of these,

You may get lucky, and although it breaks my heart to say it, you may find a replacement MDD /FW800 / G5 a lot quicker and cheaper.

There are plenty of MDD and MDD FW800 logic boards on ebay. Thats where I am going to get one just in case this one gives me problems down the road.

Does it really make a difference, so long as your motherboard or logic board in applelese supports 167mhz bus, right? For instance, suppose I decided to chuck the fw400 board I have and off of ebay get a used, or refurbished FW800 board. Granted, I also would have to get a FW800 case, since this one I have doesn't indirectly support FW800, unless I made an opening in the back.

Thats like saying gee.. if I wanted to replace my dual 1.25 processor with a dual 1.42 do I need a FW800 board to do that? No, not at all. And really, I wouldn't go to the dual 1.42 since its only 10 percent I would gain from such an upgraded processor.

I might explore sata though. I already upgraded my ATI Radeon 9000 with a 9600 from a G5, though its set to run in a G4. Its the 128MB version.

Ouch, I was hoping it wouldn't be one of those.

I think it has to be the same. My info comes from an Apple document discussing CPU upgrades.

Wait ... quoted -

Before Replacing the Processor
Important:
Apple has determined a compatibility issue between the processor and certain
fabrication levels of the logic board on some Power Mac Server G4 (Mirrored Drive Doors)
and Power Mac G4 (Mirrored Drive Doors) products. Before ordering a replacement
processor for those models, follow these steps:
1. Open the computer and check the fabrication number that is printed on the logic
board. The fabrication number is easily visible at the edge of the board near PCI card
slot 5.
2. If the logic board fabrication number is 820-1308, 820-1440, or 820-1445, do
not
order the processor module. Instead, you must replace both the logic board and the
processor by ordering the combined module: Module Set, Logic and Processor (Apple
part number 661-3654).
Replacement Warning:
When ordering this combined module set, a returned logic
board must match one of the three fabrication numbers (820-1308, 820-1440, or 820-
1445). If the logic board does not match one of these fabrication numbers, it will be
rejected.
3. If the logic board fabrication number is any other number (
not
820-1308, 820-1440, or
820-1445), order only the multiprocessor module (Apple part number 661-2730).

So make of it what you will. If your email address is in your profile, I'll email the whole document - it's a bible for MDD owners - shows you how to remove and replace everything, with photos. It's only 3.3MB.

Ok, so let me get this straight. Lets say I bought a 1.42 processor module from ebay and decided to remove the dual 1.25 processor and put the dual 1.42 in its place, are you saying that it won't work?? This is strange. Someone on here told me that so long as my logic board is 167mhz bus, it will work with dual 1.42 processor module.

NOT that I am going to get that.

Read the document, and draw your own conclusion.

It appears to only affect a small subset of the logic boards, which appear to require special processors to with them. Does that imply that the special processors require to be on one of these logic boards ? Well it should be a concern.

With 1.42GHz processors, you know there is also a concern, as these will have come from a later model MDD that didn't boot into OS9.
Unless OS9 is important to you, eventually the accumulated cost of the MDD, the memory, disks, OS upgrades, CPU upgrades, video card upgrades, SATA card, etc will have cost more than originally buying a 2nd hand G5, where all that stuff would have come free. It's a choice you make.
I decided to stop spending on the MDD, and bought a new Mac Pro.

You totally missed my question... I asked that since my logic board is a 167mhz bus based board, I saw a 1.42 dual processor on ebay and was going to get that to replace the dual 1.25, however the speed increase is very miniscule, and performance wise dictates that unless I am using really intensive software to take advantage of such a processor, I wouldn't notice really any difference at all.

Someone on here told me that so long as my MDD which btw CAN boot OS 9.2.2, though I choose not to use it, all I would need to do is replace the dual 1.25 with the dual 1.42 and I will be set. In other words, I would have an MDD W/OS 9 capability except that it would be running at 1.42 dual, instead of dual 1.25.

I did not say I was going to REPLACE the whole MDD machine with a FW800 version, no!

as for memory, I already have 2GB memory - done!
As for hard drives, I was investigating the possibility of adding SATA, but I can get my computer parts wholesale close to nothing.

Right now, I can't afford a Mac pro, and nor would I benefit from one since I don't do anything professional, such as video editing, dvd creation(making own DVD movies, this aperture thingy, photoshop, etc.). For basics, I would be wasting 5000 dollars.

If anything, I would get a mac mini intel based machine and network the two, since I would run windows apps(that too, I don't have a need at the moment). I believe we had this discussion awhile back.

Alas no, I understood your question perfectly. The only point I was trying to make was that:
- you should have a concern if you were to ever consider about putting 1.42GHz processors (from a later model MDD, into your MDD.

Other than above, I've agreed with everything you've said.

My final comment was just that there comes a point, no matter how much we love our MDD's, that it's pointless upgrading it further. An Intel Mac mini is a good choice, I've considered a Mac mini since they first came out with G4 chips, but it was always the underpowered video that put me off.

Have you read the MDD service manual I emailed ? Thought it might be of use.

Hello,
I have a Power Mac G4.Which is not starting due to some problem.
I had taken this to Apple Service Center.They told me that you have to buy a new Motherboard.
*So, I want to know that can i a put new motherboard much faster than it was.*
e.g mine was 733 Mhz and now in market 1.3Ghz Motherboard are available.

Please help me.

Ok, I still don't understand. Are you saying that if I did install the dual 1.42 processor that my machine won't work anymore? Even though, my MDD is a 167mhz bus machine? I saw a few dual 1.42 processors to be had on ebay and the sellers of all those told me I shouldn't have any problems with it not running on my system.

But, again... I am not doing it because I don't see the need to, since dual 1.25 is fast enough for me.

ok, here is another thing I did with my MDD. I replaced the standard thin finned heat sink with the copper heatsink and everything works great. I don't see why installing a dual 1.42 would make any problem for me. Like the heat sink, all I am doing is popping in the 1.42 dual processor module and removing the dual 1.25.

Nadav,

Not saying it definitely would be an issue, but

those dual 1.42GHz G4's have come from a FW800 MDD, which did have different ROMs. That would be a concern for me, if I was looking to swap them in.

There would be a small heat concern, which I'm sure you've more than compensated for by upgrading the heatsinks. Heat is produced at the ratio of the square of the processor speed for similar chips, so a dual 1.42GHz produces about 33% more heat than a dual 1.25GHz (1.42 * 1.42 is 33% more than 1.25 * 1.25).

These are just concerns I would have, but, like you said, if the benefit was there, I'd still go for it.

Ok, I will look inside my machine tonite ad see if I have that special number which won't allow me to do this. I am sure I don't, but I will see.

and yes, I have plenty of remedies to remedy the heat problem inside my computer. I have a small fan underneath the front drive cage blowing out towards the back, followed by a 120MM fan mounted on the roof of the optical drive cage - blowing out powerful blasts to keep the system cool, or cold. And lastly, a PCI SLOT FAN.