Re: Power supply replacement for Power Mac G4
Yes, they are, but they are fair questions. I'm much obliged for the very informative and detailed answers - thanks. Sean -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list
Power supply replacement for Power Mac G4
NOTE: This is a bit general, and I might yet find the answers I'm looking for in the archives. Feel free to ignore me if the topic has already been covered exhaustively there. My recently departed (in trade) Gigabit Ethernet Power Mac G4 was essentially problem-free until the power supply died about a month ago. I don't want to repeat what followed. Trouble was, without my own computer and with only sporadic access to any others, there wasn't opportunity for the research I needed to do, let alone time to find this group and get some meaningful answers. No Mac friends or ongoing relationships with a repair shop, either. The story, briefly, and then I'll get on with the questions: Came home, turned it on. Nothing. No lights, no sound, no action. Tested different power cords and outlets, nothing. Power supply. My roommate opined that it was probably a simple matter of getting any old (new) power supply and throwing it in, though he wasn't positive. He puts together his own PCs from kits, but he's not exactly a guru, and knows nothing about Apple computers. My preference was to have someone competent and qualified do whatever work was necessary. Power supply sounded a bit intimidating. Apple Store first. They confirmed the obvious, but couldn't help with the repair. They recommended an Apple authorized repair shop. Spoke with them. Seemed like they didn't want to be bothered - first suggestion was for me to find a similar machine and swap things around. Thought about it. No, I wanted them to fix it. Rebuilding the power supply is what they were going to do (their first resort as a matter of policy). But it would take a couple weeks for them to even get to it. OK. After a week they called me and said they had a similar machine they could swap my HDs and RAM into. I'd been without a computer for 2 weeks already, and with the holidays coming up it seemed possible that it might be another 2 or 3 or 4, maybe all of it just to get the answer well, we can't fix it, so we're going to have to find a replacement and wait some more. So I agreed. The Sawtooth I got back was in good shape and worked well, only problem being a new one with my very own HDs. I probably should have insisted on swapping more than just my HDs and RAM into it, but I wasn't thinking. Can't complain too much, because evidently I got a Zip Drive that might still work (at least with OS 9) and a DVD-RW instead of a CD-ROM in the bargain. But - all of this could have been avoided if I had known a power supply from a hole in the ground or had been able to find out quickly to begin with. Questions: 1. How specific is the power supply to a certain Power Mac G4 or indeed to any Apple desktop computer made since? 2. Is finding a replacement a matter of very specific model numbers (I found a lot of replacements online quickly, ranging in price from $60 to $180, but had no idea how trustworthy any of them might be and remained iffy on whether the removal and reinstallation was work I should undertake myself) or looking for certain specs? 3. Before even considering replacement, is there something a dummy can do to look at and into the power supply and evaluate the situation, something as simple as oh, it's the fuse or oh, that there cable has come loose? 4. Is there such a thing as a normal or typical lifespan for a power supply? I get the impression that replacing a power supply isn't that big a deal. Maybe something I could figure out myself if I had to. But knowing everything about what to look for in a replacement isn't something I can figure out myself. I'd like to forearm myself with some knowledge. This new Sawtooth is older than what I traded for it, after all, and the power supply might be as well. Sean -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list
Re: Power supply replacement for Power Mac G4
At 7:35 PM -0600 12/27/2010, Sean Carroll wrote: NOTE: This is a bit general, and I might yet find the answers I'm looking for in the archives. Feel free to ignore me if the topic has already been covered exhaustively there. There have been several in-depth threads on this list regarding the GigE power supplies. My recently departed (in trade) Gigabit Ethernet Power Mac G4 was essentially problem-free until the power supply died How specific is the power supply to a certain Power Mac G4 or indeed to any Apple desktop computer made since? The GigE can use a DA's supply, but not a QuickSilver's. dvwarehouse.com has 'em, but they're a bit expensive. Now and then people offer them on LEM Swap, again at awfully high prices. A better solution might be to adapt a standard PC supply. Details here: http://atxg4.com/ - Dan. -- - Psychoceramic Emeritus; South Jersey, USA, Earth. -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list
Re: Power supply replacement for Power Mac G4
NOTE: This is a bit general, and I might yet find the answers I'm looking for in the archives. Feel free to ignore me if the topic has already been covered exhaustively there. Yes, they are, but they are fair questions. Questions: 1. How specific is the power supply to a certain Power Mac G4 or indeed to any Apple desktop computer made since? VERY specific, mechanically AND electrically. The PSUs for Power Mac G4s, at least those up to the Quicksilvers, are, for the most part, a generic 300+ watt PSU, WITH THE FOLLOWING DIFFERENCES: 1) the external fasteners are M3.5-0.6, which is Apple's internal standard for a 6-32 UNC-sized fastener; Apple adopted the M3.5-0.6 fastener for all its products which required a 6-32 UNC-sized fastener with the very first Macintosh in 1984; however, the metric countries decided to make this size archaic very shortly after Apple's adoption, also in 1984, thereby making Apple perhaps the ONLY user of this fastener; not withstanding, Apple continues to favor the M3.5-0.6 fastener as there is no metric fastener with the same shear strength between the standard M3-0.5 and the M4-0.7. 2) the external connectors are Apple-standard, and vary from model-to-model, with 20 pin, 22 pin and 24 pin external connections, among other differences. 3) some models also provide monitor power. 2. Is finding a replacement a matter of very specific model numbers (I found a lot of replacements online quickly, ranging in price from $60 to $180, but had no idea how trustworthy any of them might be and remained iffy on whether the removal and reinstallation was work I should undertake myself) or looking for certain specs? The usual suspect Mac parts suppliers should be able to fix you up, using a good PSU harvested from a Mac with other problems. 3. Before even considering replacement, is there something a dummy can do to look at and into the power supply and evaluate the situation, something as simple as oh, it's the fuse or oh, that there cable has come loose? There IS a fuse, but it is in the 325 volt converter section, and is intended to protect the off-the-line section of the PSU from catastrophic failure. If the PSU's fuse is indeed blown, there is almost nothing which can be done to resurrect the PSU, save an expensive component lever repair. Besides which, that 325 volts is enough to kill you! 4. Is there such a thing as a normal or typical lifespan for a power supply? The PSU should last the lifetime of the machine. Certainly, it should last the economic lifetime of the machine, which has been over for G-series Macs for a long time now. I get the impression that replacing a power supply isn't that big a deal. Maybe something I could figure out myself if I had to. But knowing everything about what to look for in a replacement isn't something I can figure out myself. I'd like to forearm myself with some knowledge. This new Sawtooth is older than what I traded for it, after all, and the power supply might be as well. It IS possible to use a generic PSU of about 300+ watts with the following changes, which are probably WAY beyond most end-users: 1) change the 6-32-UNC fasteners to M3.5-0.6 by the simple expedient of running an M3.5-0.6 taper tap through the 6-32 UNC holes; the basic diameters of the two fasteners are nearly identical, so this expedient works in 99.44 percent of the cases; or, you can acquire new 6-32 UNC fasteners, but they probably won't be satin-finished stainless steel, like the Apple fasteners. 2) completely disassemble the new PSU; remove its internal PCB; remove its external cables by unsoldering them; harvest the external cables from the failed Apple PSU and connect these to the corresponding points within the new PSU by soldering them; reassemble the new PSU. 3) test, and pray that you didn't make even one mistake when connecting the donor cables. -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list
