Author Topic: A MDD conundrum  (Read 6942 times)

Offline Greystash

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A MDD conundrum
« on: May 07, 2022, 02:24:30 AM »
I've had a Power Mac G4 MDD (FW800 model) for years and never used it because it didn't support native OS9 booting. After I found this site a few years back I got OS9 installed and running, but it would always crash when sleeping and wouldn't wake up. I got a little further after downgrading the firmware but it would still crash so I stopped using it again.
Recently I bought a logic board for the original MDD model which did support native OS9 booting, put my 1.42Ghz stock CPU in and booted a fresh copy of 9.2.2 (from OS9General).
It works fine but again I am still getting sleep problems. This time it actually wakes the machine (powers everything back up) but when it starts to load the Finder it freezes. The menubar and windows appear but then it freezes. This also happens in OSX 10.2 but everything loads then I get a beachball cursor and can't do anything. There is no output to the OSX console, the last message displayed before it went into sleep is the still there and there's nothing new.

From what I've read it could be PSU problems. This machine is in mint condition, I don't think it was ever really used much but yes the caps still could have gone bad by now. I don't have any other cards/peripherals installed so it's nothing to do with that. It also has a new PMU battery and I have reset PMU, PRAM. One thing I did notice though is that it has 2x RAM sticks of 1GB SuperTalent PC-3200. After reading up on the specs for the MDD models it appears that 4 - PC-2700 is required for 1.2Ghz+ CPUs, otherwise PC-2100 for lower speeds. The PC-3200 works fine but this seems to be a likely culprit. Does anyone else use PC-3200 in their machines? I remember I tried OSX 10.4 on my original setup and it slept fine with no issues so maybe this RAM is an OSX only upgrade? I will buy some PC-2700 to test since that's the cheapest option for now.

My last question: is there a thread for MDD PSU replacements, or a known good source?


Offline FBz

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Re: A MDD conundrum
« Reply #1 on: May 07, 2022, 07:22:56 AM »
Recently had similar problems after putting a 1.42 GHz MDD CPU into a modified 867 MHz MDD. (I removed a resistor from the 867’s mobo to change the bus speed to 167 MHz.) I’ve also a FW400 MDD that I’ve scheduled to swap another 1.42 CPU into as well.

Had problems with the RAM (J20 RAM slot) in the 867 MHz MDD and that’s detailed in this thread… http://macos9lives.com/smforum/index.php/topic,6285.0.html I had changed the PC 2100 RAM to PC2700 RAM after the CPU swap but still had problems with the RAM in J20 RAM slot. Any and all RAM added to the J20 slot here seemed loose, as if there was axial, side-to-side play with any stick placed in that slot. Do refer to the thread just mentioned above. ;)

Do you have Startup Memory Tests turned off? Run AHT to check the RAM / RAM slots.

And I’ve never tried PC3200 in an MDD so cannot comment on its’ use. I would try the PC2700 AND check that with AHT as well because all my PC2700 tested good in other MDDs before adding to the “CPU upgraded” 867 MDD… that’s when it began the same problems you seem to be having with OS 9 and OS X.

It was suggested to me that I could use (2) 1 GB sticks of RAM and simply not use two of the RAM slots… but that’s not like me to do such a thing.

I’d definitely check the slots via AHT or the Startup Memory Tests (if you have that turned off). AND all of this… before even considering a PSU replacement.

*However, a good source for PSU replacements or re-caps is of course... our friend Andy down in Austin Texas USA. http://macos9lives.com/smforum/index.php/topic,4077.0.html

G'luck! ;)

Offline tunedbytad

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Re: A MDD conundrum
« Reply #2 on: May 07, 2022, 12:06:46 PM »
based on my extensive COVID lockdown testing
I am not an expert but my real world findings are

*in MDD single 1.25GHz*

3x 3200mhz 512 Ram chips totaling 1.5 Gig
worked the best for me

fastest on bench tests

the most stable running ProTools5.1.3
(Keep in mind I am doing 5-15 hour long song writing sessions weekly)
(20-40 hours a week )
reboots / lockup are very very rare
* I have to go dorking with my obese OMS midi setup w/ an open PT5 session to crash it.
« Last Edit: May 07, 2022, 12:18:51 PM by tunedbytad »
Hi, My name is Tad
I have a PMG4 problem
aka tunedbytad aka ProTools4 aka NotoriouSS

Offline peeperpc

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Re: A MDD conundrum
« Reply #3 on: May 07, 2022, 06:18:42 PM »
867Mhz Dual MDD, 3 sticks of PC3200 (reported as PC2600), 1 stick of PC2100, no problem here.

Offline mrhappy

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Re: A MDD conundrum
« Reply #4 on: May 16, 2022, 07:06:53 AM »
based on my extensive COVID lockdown testing
I am not an expert but my real world findings are

*in MDD single 1.25GHz*

3x 3200mhz 512 Ram chips totaling 1.5 Gig
worked the best for me

fastest on bench tests

the most stable running ProTools5.1.3
(Keep in mind I am doing 5-15 hour long song writing sessions weekly)
(20-40 hours a week )
reboots / lockup are very very rare
* I have to go dorking with my obese OMS midi setup w/ an open PT5 session to crash it.

Thanks for the interesting info on the 3200... Using a similar setup. ;D

Offline FBz

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Re: A MDD conundrum
« Reply #5 on: May 16, 2022, 09:07:28 AM »
Thanks for the interesting info on the 3200... Using a similar setup. ;D

Yes, thanks indeed. I'll now search available RAM here for PC3200 sticks.
Just returned from Mother's Day "Week"* down in Texas and can now get back to Macs.
(*Was only supposed to be 3 days away!) ::)

Offline Greystash

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Re: A MDD conundrum
« Reply #6 on: June 02, 2022, 03:50:35 PM »
Sorry for the slow response! I've been a little busy. I did end up fixing this and it wasn't the RAM thankfully! I bought 4 sticks of PC-2700 and it didn't make any difference so I put the PC3200 back in.
Strangely, it was the HDD causing the wake from sleep crash. Since I haven't been using the machine I put one of the spare mechanical HDDs in it and installed OS9. I didn't pay attention to the pin settings on the back of it (Cable Select, Master, Slave) since it was recognised as-is and booted fine. There were no other drives installed except this one, and it didn't have any of the above configurations set, no pins were shorted (not sure if that's the correct term). I took the drive out and set it to cable select, and after doing that It no longer crashes after sleeping!!
I think it still crashes if I leave a USB drive plugged in while it sleeps but I wasn't clear with my note so maybe that was related to the HDD, I'll have to check again when I use it next.

Thanks for the help everyone! I'm glad I can keep the faster RAM in this and am very happy I now have a functional MDD!!