PowerMac G4 MDD PSU Replacement

[Troika]

I recently came into possession of an old MDD. Its the 1.0Ghz DP model lacking the FW800 port. I got it in AS-IS condition with the only things missing on it was the pram battery and the hard drive. Getting a new pram battery wasn't difficult, my local Batteries Plus stocks them and I have an old 40GB ide drive that came out of my eMac when I upgraded the storage on it. When I hit the power button, it flashes white once then turns back off. No fan noise or anything. I opened it up, made sure everything was firmly in place and blew out all the dust. Same behavior. I tried different ram, I kept the old 1GB kits (2x512MB) from my eMac so I tried that one but nothing changed. I removed everything I could and just left the gpu for display out, cpus, ram and power. No response. I figured that the issue had to be one of the components there. Today at work, I checked the voltages following these instructions here and this pin out diagram. I found that the reading between pin 12 and pin 14 red 14.5V with occasional spikes to 22V, pin 1 to pin 12 red 4.5V, and pin 12 to pin 24 gave a reading of 0V. I retested the last one a few times to be sure it was accurate. I'm pretty sure the psu is, at the very least, the primary faulty component but there may be issues elsewhere.

With that, I get to my question. Is there anywhere to get a new/working psu replacement for the one I have? All the places I checked that seem reputable sell replacement 360W units north of $120 usd. I really don't want to spend that much so I was wondering if there were any other alternatives that are more reasonably priced.

[FBz]

Try Andy Cuffe down in Austin, Texas.
http://macos9lives.com/smforum/index.php?topic=4077.0
More info in that thread.

He's a member here too...
AND was offering discounts for other members.

[IIO]

i dont want to insult your intelligence, but did you try pressing PMU button and resetting PRAM yet.

and when you need a PSU and it is not urgent, best you can do is probably to find someone selling his old quicksilver with something else broken - that is what i did last time.

[Troika]

Try Andy Cuffe down in Austin, Texas.
http://macos9lives.com/smforum/index.php?topic=4077.0
More info in that thread.

He's a member here too...
AND was offering discounts for other members.

Yeah, shortly after posting, I saw the post talking about Andy doing psu repairs. I just dropped off my psu at his place about six hours ago. He said it'd be ready by Monday and it'd be $75. Definitely way cheaper than buying another one that may or may not work while having all the caps replaced with much higher quality ones.

[Troika]

i dont want to insult your intelligence, but did you try pressing PMU button and resetting PRAM yet.

and when you need a PSU and it is not urgent, best you can do is probably to find someone selling his old quicksilver with something else broken - that is what i did last time.

I did and it did nothing. No amount of PMU and PRAM resets will change the fact that the psu is faulty. Andy confirmed that the voltages I got at work with a multimeter were indeed correct and the psu is busted.

[FBz]

“He said it'd be ready by Monday and it'd be $75.”

SEVENTY-FIVE DOLLARS!!!

Yet another advantage of living ‘round Austin AND being a member here.
(Zero cost for shipping too - in your case.)
Thanks for taking it to Andy and hopefully, keeping him at it.

Oh yeah, and “Keep Austin Weird”.

[Troika]

“He said it'd be ready by Monday and it'd be $75.”

SEVENTY-FIVE DOLLARS!!!

Yet another advantage of living ‘round Austin AND being a member here.
(Zero cost for shipping too - in your case.)
Thanks for taking it to Andy and hopefully, keeping him at it.

Oh yeah, and “Keep Austin Weird”.

Hehe, a hidden benefit at that. I happened to move to Austin from the DFW area last year due to losing my job due to covid. I decided to roll the dice and see what fate would await me there. Over a year later, I'm still in Austin with a fun job fixing custom PCs and my newly repaired fruitmachine.

Now all I need is to pick out some nice upgrades to deck out the nicest G4 MDD for OS 9 and OS X, Probably Tiger since I tried using Leopard on an old eMac and that didn't perform very well.

[Troika]

One step forward, two steps back. After I went and found my cd spindle that has my OS 9 and OS X 10.4 disks, I came back to my room to try and turn on the MDD only to hear the fans ramp quickly to max speed. Upon closer inspection after trying the ram in single dimm configurations and doing a PRAM reset, I checked under the heatsink to find brownish yellow scorch marks on the right side of the heatsink and around the right side cpu. I'm now in need of a new cpu. Would there be a noticable performance increase in going from a 1.0Ghz DP to a 1.25Ghz DP?

[FBz]

There’s an ongoing debate as to just how much a dual processor really means performance-wise (overall), as most programs don’t or can’t fully utilize them. And then there are those that swear by the single 1.25 GHz processor’s overall performance. I’ve always preferred my 1.25 GHz DP MDD - and I just found a 1.25 single CPU here that I will now have to eventually test & compare.

As to 1.25 vs. 1.0… well it’s +.25 GHz difference… so I’d say not a whole lot.
So that sorta leans into basically… availability and a cost/price comparison between the two.
AND again, single or double?

I know. No real help from me. Sorry.

Did you not recently renewed the heatsink paste on that 1.0 GHz DP CPU?
AND, there was no fan blowing on that heatsink - IF you were operating as pictured above.

Want to try a single 1.0 GHz CPU? / PM me.
I’m now staring at one of those too.

Does your 1.0 DP look anything like this one’s scorched processor?