Dirk Monson Posted April 8, 2007 Share Posted April 8, 2007 I recently acquired an iMac G5 logicboard (1.6Ghz) that had the leaky capacitor problem. Anyhow, I fixed this problem (installed new capacitors) and now the logic board is good as new. So here's my question. I want to use this logic board as a standalone unit without the iMac shell. I've seen this done before, however in that example he used the actual iMac G5 power supply. I don't really want to have to spend another $100 on just a power supply. What other options are there for power supplies for the iMac G5 logic board? Is it possible(has anyone done this) to rig up a standard ATX power supply (I know the pinout is different)? Would it be possible to use a power supply from a Power Mac G5? Any suggestions on this would be greatly appreciated! Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/ Share on other sites More sharing options...
cnoyes72 Posted April 9, 2007 Share Posted April 9, 2007 I recently acquired an iMac G5 logicboard (1.6Ghz) that had the leaky capacitor problem. Anyhow, I fixed this problem (installed new capacitors) and now the logic board is good as new. So here's my question. I want to use this logic board as a standalone unit without the iMac shell. I've seen this done before, however in that example he used the actual iMac G5 power supply. I don't really want to have to spend another $100 on just a power supply. What other options are there for power supplies for the iMac G5 logic board? Is it possible(has anyone done this) to rig up a standard ATX power supply (I know the pinout is different)? Would it be possible to use a power supply from a Power Mac G5? Any suggestions on this would be greatly appreciated! Look at www.xlr8yourmac.com. There is a pinout of the iMac G5 17" rev a power supply there. The easiest way to do the conversion would be using an ATX extension cable (24 pin) and hacking off the last row of pins. Then you would just need to rearrange the wiring between the PS and the Mac (using the extension cable keeps you from hacking apart your ATX PS in case you ever want to use it some where else). HTH, -Chris Noyes Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-343479 Share on other sites More sharing options...
Dirk Monson Posted April 9, 2007 Author Share Posted April 9, 2007 Chris, That helps a ton. Hopefully by the end of the week I'll have a spare moment to make the cable. I'm assuming the +24V is used to power the LCD inverter and probably isn't really necessary since I'll be using an external display. What are your thoughts on that? Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-343607 Share on other sites More sharing options...
cnoyes72 Posted April 9, 2007 Share Posted April 9, 2007 Chris, That helps a ton. Hopefully by the end of the week I'll have a spare moment to make the cable. I'm assuming the +24V is used to power the LCD inverter and probably isn't really necessary since I'll be using an external display. What are your thoughts on that? Yeah, the 24VDC line looks to be for the display (backlighting). I have a 1.8GHz board from a 17" imacG5 I'd like to use with an ATX PS I have sitting around. The only "issue" I see is trying to get the internal optical drive working; it uses a laptop style connector for the optical drive (same connector that is in other laptops and on the back of the optical drive unit itself). Too bad they didn't use SATA for that connection.... I'm looking to mount this in a Cherry wood case. -Chris Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-343677 Share on other sites More sharing options...
learning_bird Posted April 30, 2007 Share Posted April 30, 2007 Did you had any luck with using an ATX PSU with the iMac G5 board? Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-356281 Share on other sites More sharing options...
psychozz Posted September 12, 2007 Share Posted September 12, 2007 I am also interested in this! What I can see, the only thing to do is to rewire the three +12V pins and somehow fix 24V to the extra 22nd pin at the end of the connector, am I right? But how do you get 24V out of a 12V ATX power supply? Would it work to use a second power supply that outputs 24V just to that pin and connect the ground to the extra ground connector at the end? The iMac's power supply pinout: http://www.xlr8yourmac.com/images/imacg5_p...pply_pinout.gif Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-446430 Share on other sites More sharing options...
tayklor Posted December 31, 2007 Share Posted December 31, 2007 I am going to do the same thing as I can get iMac G5s with bad power supplies for $40 each. Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-559729 Share on other sites More sharing options...
hoodmulti Posted January 12, 2008 Share Posted January 12, 2008 I just tried to use a normal PC ATX power supplied, swapped in two +12V cable at the pin, but left the +24V pin unplugged, and it worked. My dead iMac G5 resurrected. It would be great if anyone knows what the +24V is for? Cheers. Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-576065 Share on other sites More sharing options...
ESP Posted March 21, 2008 Share Posted March 21, 2008 HI using an external Monitor?... please let me know , i've the same problem. bye, thanks in advance. Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-676470 Share on other sites More sharing options...
tuffhamster Posted June 17, 2008 Share Posted June 17, 2008 WOW thanks everyone. I was about to sell of my dead imac as faulty on ebay and thought I would give this a go. Had to just change over 2 x 12v wires and it works perfectly Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-786882 Share on other sites More sharing options...
jphuard Posted June 22, 2008 Share Posted June 22, 2008 Hey I was wondering if anyone would mind posting pictures? It'd be really helpful for anyone who has yet to do it and would rather not worry about screwing up ;-) (like me) Thanks Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-792530 Share on other sites More sharing options...
phutterman Posted June 24, 2008 Share Posted June 24, 2008 I've recently considered the same thing, as I acquired an iMac board as well. However, at this point, I am using the iMac power supply, as I may also connect its LCD panel, which requires the original power supply for the higher voltage. I do have an ATX extension cable which for the moment I am using just to extend the iMac power supply's cable (as it is just straight through) but also might use it to adapt an ATX power supply to the iMac board, and then use the iMac power supply just to power the display, though that would be another whole big project. I'm putting the iMac board into a PowerMac G5 case that had a coolant leak, so I got it for free, and just had to clean the corrosion out myself. Once it's done I may post some pictures. Anyway, I just wanted to remark that if you're using an ATX power supply, you might consider getting a laptop optical drive to IDE adapter (ie http://www.dealextreme.com/details.dx/sku.10573). It lets you connect a regular IDE drive to the laptop optical drive connector on the iMac motherboard. However, it is only for data, not power, so you would also need to connect the drive to a regular 4-pin Molex from the power supply as well. At the moment, I can't do this, as I'm using the iMac power supply, which only has the 20-pin connector and no 4-pin ones, but this would be one reason I'd switch to an ATX. Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-795642 Share on other sites More sharing options...
BigDyno Posted October 27, 2008 Share Posted October 27, 2008 I know this is an older post, but i figure i found this thread through Google, so I imagine someone else will. I was given a "broken" iMac g5 20-inch computer. I was told that the power supply had to be replaced. I found a powersupply for sale for $10 (rather then the $200 the tech quoted me) But the psu was pulled from a 17 inch, (and has different part number.) Does anyone think this makes a difference? Will it work in my larger 20 inch? After reading this thread and seeing a regular atx psu was used, it makes me think that there would be nothing different between the two. Any reply's would be great, Thanks! Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-946142 Share on other sites More sharing options...
Reveeen Posted October 28, 2008 Share Posted October 28, 2008 BigDyno: The tools you need are posted in this thread............ compare the pin outs at http://www.xlr8yourmac.com/ keeping in mind that if the same, the wattage is likely to be smaller. Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-946571 Share on other sites More sharing options...
Eligos Posted January 2, 2009 Share Posted January 2, 2009 I know this is an old thread but since I am about to swap out my dead iMac 20" PSU for an PC ATX, I need a few precisions. Some of you here used a PC ATX successfully. Could you please tell me if your main LCD works with this setup or do you need an external monitor since the +24v isn't being used? Many thanks for your reply, FS Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-1023521 Share on other sites More sharing options...
GreggyB Posted February 24, 2009 Share Posted February 24, 2009 I am going to do the same thing as I can get iMac G5s with bad power supplies for $40 each. Hey! I know that this post was some time ago (about 2 years), but I'm brand new here and found this thread-looking for info on replacing a power supply on the iMac G5. So, I'm wondering if this statement you gave is still true? Where can one such as myself get a G5 for $40? Thanks so much. Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-1090492 Share on other sites More sharing options...
Nyleveia Posted January 26, 2010 Share Posted January 26, 2010 I felt i would add my experiences, since this would also be my first post also. I have a 20" iMac G5, 1.8ghz that wasn't booting at all, just led 1 illuminated, mac store said it was the logic board, i thought otherwise. I connected an atx psu switching the above mentioned pins for 12v+ and hey presto, it booted with chime and continued, only problem being that there was no display, i recall someone posting that the 24v is for firewire - this may well be the case but i can confirm that for the 20" g5, this is needed for backlight to function, i connected the old psu and grounded pin 14 (to tell it to turn itself on), with the 24v and ground connected to the corrosponding connectors on the g5, the result was the machine booted just fine, with display functioning perfectly. Now its just a case of me getting a working psu for it, or having a go at replacing all of the caps in it and hoping one of them is dead (none of them are obviously dead, no leakage or expanding). Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-1396003 Share on other sites More sharing options...
Nyleveia Posted January 27, 2010 Share Posted January 27, 2010 I've encountered a really odd situation, when connecting the original psu for 24v+ source (connecting pins 14 and 15 to keep it on), the psu was emitting a low squeel, however i continued and reinstalled osx, after doing so and installing various updates i came to remove the atx psu, and just out of curiosity, reconnected the original psu, which had stopped squeeling about half way through a reinstall. And low and behold, its now back to working just fine, weird! Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-1397624 Share on other sites More sharing options...
jppetertil Posted April 20, 2010 Share Posted April 20, 2010 Thanks so much for all this info. I put a new ATX PSU into my iMac G5 17" power pc and everything seems to be working great with only 12V hooked up to the 24V pin. I also replaced some logic board capacitors. Apple had estimated $600-700 for these repairs and I did it all for about $65. Awesome! Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-1452359 Share on other sites More sharing options...
kiwiron Posted May 31, 2010 Share Posted May 31, 2010 Hi folks, this is another question really, as I'm new so can't post a new topic yet. I've a G5 20" isight with a blown 661-3780 power supply. The DC out for these is only 5 pins and the supply itself states 12.1 volts and 15.4 amps. Can anybody please indicate the voltages on the 5 pinouts. The wires are 2 grey, 2 black, and 1 brown. The grey and black wires are joined on the power supply circuit board, so its really only 3 pinouts. I want to test the machine before splashing out on an expensive replacement, but haven't been able to find the pinout voltages anywhere. Getting desperate! Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-1478895 Share on other sites More sharing options...
kiwiron Posted May 31, 2010 Share Posted May 31, 2010 Hi folks, this is another question really, as I'm new so can't post a new topic yet.I've a G5 20" isight with a blown 661-3780 power supply. The DC out for these is only 5 pins and the supply itself states 12.1 volts and 15.4 amps. Can anybody please indicate the voltages on the 5 pinouts. The wires are 2 grey, 2 black, and 1 brown. The grey and black wires are joined on the power supply circuit board, so its really only 3 pinouts. I want to test the machine before splashing out on an expensive replacement, but haven't been able to find the pinout voltages anywhere. Getting desperate! Typical, that I found the info right after posting! For an imac G5 17"/20" isight (early 2006) My EEE code is UQP with an 661-3780 power supply with only 5 pinouts these are: Grey: +12V Grey: +12V Black: ground Black: ground Brown: PFW (battery powered signal between +3 and +6.5 volt to switch power supply on) Hopefully this might help somebody else. Cheers 1 Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-1478919 Share on other sites More sharing options...
MacintoshHealer Posted June 22, 2012 Share Posted June 22, 2012 Tanks for the pin out! PFW , the brown line is a voltage coming out of the PSU or going in? Link to comment https://www.insanelymac.com/forum/topic/47788-imac-g5-power-supply-question/#findComment-1828619 Share on other sites More sharing options...
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