Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[blazer1878]

Hello, I have g4 mdd that i got for free. I repasted it, replaced ram with one, that surely works and replaced psu with xilence 400w one that matches specs of og one with pins reseated to match pinout of original psu. After building everything together and booting os 9 using netboot, due to dvd drive being yoinked out to house psu i got error that one of my processors is faulty. This doesn't affect mac os 9, but it prevents me from booting os x and possibly causes machine to fail to enter target disk mode. Pram battery is new, no pins are bent on motherboard.

[aBc]

Welcome aboard Blazer1878!

Now I wonder if it might have something to do with the ATX PSU — but that is just a guess. I’ve never attempted an MDD ATX conversion myself but I understand that many who have tried, often run into problems. Maybe someone here has done so successfully?

One member here, Greystash has done so using an ATX adapter cable:
https://mac-classic.com/articles/power-mac-g4-mdd-atx-conversion/
Plus: https://www.ebay.com/itm/143542889309
And for more info, he offers this link too: http://atxg4.com/mdd.html

You say that it does not affect OS 9 but that it will not boot any version of OS X?

I’d review Greystash’s comments and links… and maybe someone else here will also chime in.

It seems like it’s always a question of checking and then re-checking the wiring.

Perhaps you can place the PSU outside of the case long enough to place the DVD drive back into the case for a little while… which might allow you to boot from a diagnostic disc to check other “things”?

How much total RAM is installed?

Can you post detailed pictures, or diagrams of your ATX wiring?
Greystash (or someone else) might be able to detect possible problems.

*I reduced your image file sizes in original post.

[blazer1878]

I use wiring from atxg4, but instead of using molex to p4 i sacrificed cpu 4 pin
As for ram i have one stick of 512mb installed as system refuses to boot with more sticks (it chimes, but after that image doesn't appear)
Also there is a weird issue with dvi output:  when dvi monitor is present it completely ignores power button and i have to replug all in one i use as a monitor, due to it being my only digital video supporting monitor with supported resolution
By the way is it possible to use target disk moded ibook g4 as dvd drive replacement for this software because i reused dvd drive from mdd on my p4 machine

[blazer1878]

Pics of wiring

[aBc]

Thanks for the pics!

I might not be able to see it in your pics, but I cannot see the “power ok” (POK) line from the ATX connected to pin 18 [as mentioned by ATXG4].

“Apple systems don't utilize the power ok (POK) line, but it is needed for an ATX power supply to function properly. I've found it best to connect the POK line to the 3.3v from the power supply. You can do this either via splicing/soldering, or you can just insert it into one of the 3.3v connections to the motherboard. I usually plug it in to pin 18.” -ATXG4 — http://atxg4.com/mdd.html

Other than that, it appears that you’ve matched the recommended pinout configuration for the MDD. Maybe someone else can spot a possible problem?



Only other thing that I might check would be the actual, individual output voltage of each wire from the ATX PSU with a multimeter. And again, someone else here that might have actually done this ATX PSU conversion may (hopefully) chime in. Regretfully, I have Quicksilver ATX conversion waiting on my backlog of projects so I cannot undertake a similar MDD conversion attempt at this time.

It might be helpful to also provide information on which specific ATX PSU (and its specs) that you are using?









Note the grey wire [power ok (POK) line] between the two orange wires, in the left-side (top row) image above?

[blazer1878]

I have brown and not grey cable connected to pin 19

[blazer1878]

Done, will test this after i will get my new radeon 9000 because original gpu lacks vga and is damaged

[aBc]

Well, that GPU may make a big difference.

AND probably, makes no difference... pin 18 or 19?

Can you boot your MDD into Target Disk Mode? If so, then you might be able to run diagnostics on it using the G4 iBook? Maybe.

Currently I am also looking for… ASD v2.1.5 (Apple Service Diagnostics) for the MDD because if you cannot access your machine from the G4 iBook using Target Disk Mode to possibly run diagnostics… then ASD v2.1.5 might be a better, more direct route. (If you don’t have an earlier model of MDD requiring a different version of ASD).

I’ve already forgotten if you’ve a firewire 400 or 800 MDD — or perhaps you’ve not specified the exact MDD that you do have? And then again, in order to use ASD you’ll have to have an onboard DVD drive in order to boot from it. (Or a bootable external DVD drive.)

Another little note: Disconnect and or remove every non-essential peripheral (and network connection) AND internal cards... from your machine, other than the absolute bare essentials for it to function.

AND it’s odd that the machine will only accept 1 stick of RAM? This leads me to also wonder IF maybe the machine’s motherboard was somehow possibly damaged prior to your possession? (Especially if we can possibly rule out ATX PSU problems.)

*The “correct” version of ASD for your specific machine, option-key booted from a burned disc allows one the option of either booting into Open Firmware or via the OS X operating system. BUT you have removed the DVD drive in order to accomodate the ATX PSU.

Will the MDD accept and read & write to a USB connection? (Thumb drive or external USB drive.)

[blazer1878]

As for tdm it doesn't work on this thing yet still maybe because of dvd drive being not present, but i can put my spare hdd into mbp 2008 and boot from it (i reinstalled 10.4 and 10.5 this way on 35 cycle ibook)
Also this is first batch mdd from 2002, that supports native os 9
Expansion slots are not related because i don't have any expansion cards and i removed modem

[aBc]

Try booting while holding down the "t" key.

[blazer1878]

When i do exactly that it shut downs, same thing with of command

[aBc]

When i do exactly that it shut downs, same thing with of command

Not good.

Too bad you’ve no other MDD mobo to test with the ATX.

And without visual comparison of the two processors — can’t tell if one has been heated more than the other… in which case, one of them has possibly failed or is failing. There’s also the possibility that the daughtercard itself may be warped and not making full, adequate contact(s). [We’ve seen that before.]

*Applying direct, downward pressure on the heatsink (with the palm of your hand) might provide different results?

When you cleaned off the old heatsink paste before repasting, what condition was it in? Totally baked? And you don’t remember if one processor appeared different; as if it had been overheated?

Easier to remove the CPU and visual check. And easier to replace the CPU, rather than to pull and replace the mobo.

So if you go to the… time, trouble and expense of replacing the motherboard and then discover no change, you’d need to then possibly replace the CPU.

In the meantime, you can very closely inspect the mobo (top and bottom) looking for any signs of overheating or other possible damage to the myriad of tiny electronic components and traces.

So, if the ATX PSU is okay and functioning properly, I’d suspect the CPU and / or the motherboard at this point. However, the questionable GPU may be the root of your problem. And maybe after its replacement, conditions might change?

BUT with that processor warning… well, who knows?

Sorry, no quick-fix easy answers for you. Maybe I’m missing something, but as always… not easy to diagnose problems without the advantage of having machines close at hand.

If you’ve already ordered the new GPU, please report back if any change after installation.

Too many variables at this point.