power supply

Patth9 · Feb 27, 2015

Does anyone know if a power supply for G4 MDD Apple Model No:M8570, can be opened up and dusted?

I know that sounds odd, but before I start taking this mac apart for cleaning, I thought I'd better ask.

Does anyone one know where there are refurbished PSU (Supply Units) can be purchased?

Patt

harrymatic · Feb 27, 2015

You certainly can - and I would thoroughly recommend it. I cleaned all of the dust out of mine and my system ran a lot quieter and about 5 degrees cooler. There's usually a few refurbished ones on eBay as well as plenty of working used ones.

Patth9 · Feb 27, 2015

Thanks very much. That's what I'm going to do.

Patt

Patth9 · Mar 2, 2015

Connecting the dots

Today we tried the option of blowing out the inside of the power supply unit (PSU). It was harder getting back together than taking it apart. My husband got the honors of dissecting the G4 MDD back together, it has been running without freezing or getting loud and obnoxious, for about 3 hours. I am almost afraid to mention that it feels a little faster. The interesting thing is that since we disconnected the necessary connectors to be able to get the PSU out, and of course, reconnected the connectors, could that be the reason the Dual 867 is running so well? My husband worked on copiers for years and he says that many times he had a problem with copiers and all it took was to disconnect and reconnect the connectors, and it solved many of the problems. That last sentence is certainly connected.

I know this old Mac will one day be unfix able, but maybe I will go before it does.

Thanks to those who offered their help. Wish me luck!
Patt

ctmpkmlec4 · Mar 2, 2015

Patth9 said:
Today we tried the option of blowing out the inside of the power supply unit (PSU). It was harder getting back together than taking it apart. My husband got the honors of dissecting the G4 MDD back together, it has been running without freezing or getting loud and obnoxious, for about 3 hours. I am almost afraid to mention that it feels a little faster. The interesting thing is that since we disconnected the necessary connectors to be able to get the PSU out, and of course, reconnected the connectors, could that be the reason the Dual 867 is running so well? My husband worked on copiers for years and he says that many times he had a problem with copiers and all it took was to disconnect and reconnect the connectors, and it solved many of the problems. That last sentence is certainly connected.

I know this old Mac will one day be unfix able, but maybe I will go before it does.

Thanks to those who offered their help. Wish me luck!
Patt

If it's running cooler, than you can certainly say that it's performing better. However, simply cleaning the power supply won't make it run faster. There are situations where unplugging a device from power and plugging it back in will reset the device. Unless the Mac had never been power-cycled before in its life, I would say that's not the case in this situation. Glad you got it fixed!

poiihy · Mar 2, 2015

So you cleaned the PSU with a blower? How good is it? Does the fan still appear dusty or is it almost absolutely clean?

My beige G3 PSU (which I don't use for the beige G3) was really filthy so last weekend I opened it up and brushed it out with a paintbrush. Compressed gas duster doesn't really work for the dust that is stuck on. I vigorously brushed everything and then blew the dust out with a compressed gas duster, then repeated, until there was almost no dust left. I did a lot of brushing all over the fan to get all dust off so it looks like new. I suggest you do this, it's much better than just blowing it out and still having the fans covered with dust. The fans collect a lot of "hard dust" that needs brushing to get off.

Patth9 · Mar 3, 2015

poiihy said:
So you cleaned the PSU with a blower? How good is it? Does the fan still appear dusty or is it almost absolutely clean?

My beige G3 PSU (which I don't use for the beige G3) was really filthy so last weekend I opened it up and brushed it out with a paintbrush. Compressed gas duster doesn't really work for the dust that is stuck on. I vigorously brushed everything and then blew the dust out with a compressed gas duster, then repeated, until there was almost no dust left. I did a lot of brushing all over the fan to get all dust off so it looks like new. I suggest you do this, it's much better than just blowing it out and still having the fans covered with dust. The fans collect a lot of "hard dust" that needs brushing to get off.

Oddly, there was very little dust inside the PSU or on the other parts for that matter. The mac was given a new/different PSU about 4 years ago when the original PSU stopped; an almost new PSU took it's place. So, the canned air didn't have much work to do.

The reason the connecting and reconnecting seems to make sense is because there wasn't the dirt as expected, not even on the fans.

The Mac may not be faster, that's true, but I've been working on a video for youtube, and before the tear down adventure on the Mac, I was lucky if I could get the Mac to stay active for one hour without either freezing or getting a sped up fan noises. The only thing that has happened is the "death" screen, which I believe is due to my hard drive, as this same "surprise" has followed me from one computer to the other. I just have to be sure when I walk away, I've saved everything.

I have no idea what a "power-cycled" is, do tell. The items that were disconnected etc. were the necessary items in order to get the PSC out of the Mac.

poiihy · Mar 3, 2015

Patth9 said:
Oddly, there was very little dust inside the PSU or on the other parts for that matter. The mac was given a new/different PSU about 4 years ago when the original PSU stopped; an almost new PSU took it's place. So, the canned air didn't have much work to do.

The reason the connecting and reconnecting seems to make sense is because there wasn't the dirt as expected, not even on the fans.

The Mac may not be faster, that's true, but I've been working on a video for youtube, and before the tear down adventure on the Mac, I was lucky if I could get the Mac to stay active for one hour without either freezing or getting a sped up fan noises. The only thing that has happened is the "death" screen, which I believe is due to my hard drive, as this same "surprise" has followed me from one computer to the other. I just have to be sure when I walk away, I've saved everything.

I have no idea what a "power-cycled" is, do tell. The items that were disconnected etc. were the necessary items in order to get the PSC out of the Mac.

Power cycle is to unplug and plug back in, or turn off and turn back on. You "cycle" the power.

Patth9 · Mar 3, 2015

Oh, that!

poiihy said:
Power cycle is to unplug and plug back in, or turn off and turn back on. You "cycle" the power.

Oh, that!

Every time I turn on my Mac, I have to unplug and replug to get it to turn on.

bunnspecial · Mar 3, 2015

Patth9 said:
Oh, that! Every time I turn on my Mac, I have to unplug and replug to get it to turn on.

I have an MDD that does that. I think the PSU is on the way out, but haven't investigated any further than that.

ctmpkmlec4 · Mar 3, 2015

bunnspecial said:
I have an MDD that does that. I think the PSU is on the way out, but haven't investigated any further than that.

There is an eBay seller who has a refurb service for MDD power supplies. It's $75, I think. Pretty reasonable if his work is good. Can't vouch for it since I haven't had mine overhauled.

bunnspecial · Mar 3, 2015

ctmpkmlec4 said:
There is an eBay seller who has a refurb service for MDD power supplies. It's $75, I think. Pretty reasonable if his work is good. Can't vouch for it since I haven't had mine overhauled.

I bought one from him, and it's great. I put it in the second MDD I bought-a dual 1ghz that I'd originally intended to replace my Quicksilver(the QS is actually faster in the real world thanks to the L3 cache).

My problems is that I don't really use my MDDs that much, and have enough of them that I can't stomach the cost of that to get them all going. The dual 1ghz and one of the single 1.25s(which has the flaky PSU I mentioned earlier) have PSUs in them pretty much permanently. I have another working PSU that I move around on an as-needed basis.

poiihy · Mar 3, 2015

Theres this article about MDD power supplies and how to fix:
https://discussions.apple.com/thread/5110652
According to this, he simply discharged the capacitors and it worked.

CapnCrunch53 · Mar 4, 2015

bunnspecial said:
I have an MDD that does that. I think the PSU is on the way out, but haven't investigated any further than that.

Mine was like since I've owned it; a couple weeks ago I went to fire it up and the PSU was dead. So that may well be that's a bad sign.

ctmpkmlec4 said:
There is an eBay seller who has a refurb service for MDD power supplies. It's $75, I think. Pretty reasonable if his work is good. Can't vouch for it since I haven't had mine overhauled.

I just got a power supply refurbished by him (not the one that died; I had a dead spare which is what I got refurbished), he had it fixed and shipped back out the day after he received it, and the cost of refurbishing is less than most used supplies on eBay, which may or may not be on the verge of death themselves. I'd personally recommend his service.

I've actually got a side question about MDD power supplies: is it bad to leave them plugged in but off? I know it is if you're using an ADC monitor, because it draws power from the MDD's power supply without the fans running to cool it, but what about just by itself without an ADC monitor? Reason I ask is mine seemingly died during the few months that I didn't power it up...

Patth9 · Mar 8, 2015

bunnspecial said:
I have an MDD that does that. I think the PSU is on the way out, but haven't investigated any further than that.

My G4 has been doing this (needing to be unplugged etc. after each turn off) for a very, very, long time. It's inconvenient, but doable.

Patth9 · Mar 8, 2015

Happy so far

It's only been about 5 days since I dusted out the G4 including unplugging all that was necessary to remove the PSU (power supply unit) and the only thing that has happened has been what I call the "death screen" once a day. Side Note: The death screen is the one where it slowly covers the screen and tells you so in many, many different languages that you should be afraid, be very afraid; this little gift has been giving for years.

I've had no freezes, no difficulties starting up, though I think I will swop my backup disc for my current start up disc and see if the backup disc pops up without out scaring me with the folder/question mark display. The backup disc has had a lot less wear.

With the help from many on this link, I managed to finish my youtube video using Adobe Premiere 6.5 from the nineties, which is a big reason why I'm still trying to hang on to my G4.

Patt

I've had no freezes, no difficulties starting up, though I think I will swop my backup disc for my current start up disc and see if the backup disc pops up without out scarring me with the folder/question mark display. The backup disc has had a lot less wear.

With the help from many on this link, I manged to finish my youtube video using Adobe Premiere 6.5 from the nineties, which is a big reason why I'm still trying to hang on to my G4.

Patt

ctmpkmlec4 · Mar 8, 2015

The "death screen" is known as a kernel panic. Bad RAM is a common culprit.

Patth9 · Mar 10, 2015

ctmpkmlec4 said:
The "death screen" is known as a kernel panic. Bad RAM is a common culprit.

I have 3 521ram and 1 256 ram =2GB. I've been going to order another 521, but how do I know which one might be failing?

Patt

ctmpkmlec4 · Mar 10, 2015

Do you have a copy of Apple Hardware Test for your machine?

bunnspecial · Mar 10, 2015

ctmpkmlec4 said:
Do you have a copy of Apple Hardware Test for your machine?

In addition to that, there's always the trial and error method.

Remove one stick, boot the computer, and see if it kernel panics after a few minutes. If it doesn't, replace that stick, remove another, and continue until the system is stable.

Patth9 · Mar 11, 2015

bunnspecial said:
In addition to that, there's always the trial and error method.

Remove one stick, boot the computer, and see if it kernel panics after a few minutes. If it doesn't, replace that stick, remove another, and continue until the system is stable.

Guess it will be the trial and error. I did some Googling and since I've never had a NEW G4 or G5 for that matter, I never got any disks. So, trail and error will suffice. Thanks for your suggestions.

Patt

ctmpkmlec4 · Mar 13, 2015

Have you been able to resolve the kernel panics?

Patth9 · Mar 19, 2015

ctmpkmlec4 said:
Have you been able to resolve the kernel panics?

I haven't used the G4 for a while, as the video I made is finished and up on Youtube. However, I am bowl over that you took the time to ask me, thank you.

I know I need to order some new memory sticks, which I will certainly be doing. When I learn more, I will re-post.

I also have been provided with a Apple Hardware Test by bunnspecial "Originally Posted by ctmpkmlec4 Do you have a copy of Apple Hardware Test for your machine?"

Again, thanks to you both, Bunnspecial and ctmpkmlec4 for your help.

Patt

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