Re: MDD G4 Power Supply variations
I bought a used dual-1.25 MDD about a year-and-a-half ago from a college in Washington state, and it arrived with a dead PSU. After checking prices for replacement PSUs (from $150-$500, at the time), I did a lot of googling and reading about the situation. Among other things, I learned that the 400-watt PSU was the original PSU for this CPU, and the 360-watter was the replacement offered by Apple when the original started dying like flies; as it turns out, the 360 wasn't much of an improvement. The real problem was (is) just a very bad original design, probably forced by trying to fit two GHz+ processors into a case designed for one 350 MHz chip. To cut to the chase, and as Dan and Ted suggest, I decided to invest in a very-good quality 350-watt ATX PC PSU ($50 from Newegg), though it took a bit of looking to find one that would fit the MDD case. I rewired the harness myself - all it requires is patience and minimal soldering skills. True enough, if you go this route, you'll not be able to use Apple displays (unless you add a separate 28-volt PSU brick) - but as I have no Apple displays nor plan to get any, it's not an issue for me. So far, I've had not one second of trouble from this arrangement - none of the very common power-up problems endemic to the MDDs. I strongly urge anyone who experiences PSU problems with their MDDs to just bite the bullet and replace the Apple PSU with a generic PC ATX PSU: Much cheaper and much more reliable than the Apple-only fixes. -- 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
MDD G4 Power Supply variations
I have a pair of Dual 1.25 MHz MDD G4's which have been my graphics workhorses since I bought them new. Recently the power supplies failed on them both within a few days of each other. I removed the power supplies and was surprised to find that the power supply in the first computer I bought is an AcBel 400 Watt Rev B and the power supply in the second one I bought a few months later is an AcBel 360 Watt Rev A. Does anyone know why Apple used two different power supplies in two virtually identical G4's? Or which one is the better power supply? Did they have problems with the 360 W and replace it with the equally undependable 400 W? These AcBel power supplies were made in China. Doing a little reading I quickly discovered that Apple had problems with them immediately. There is an online service, National Ram Electronics, that repairs the AcBel G4 power supplies. Does anyone know if these bits of Chinese junk are worth repairing? -- 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: MDD G4 Power Supply variations
At 1:22 PM -0400 10/7/2010, James Morgan wrote: I have a pair of Dual 1.25 MHz MDD G4's which have been my graphics workhorses since I bought them new. Recently the power supplies failed on them both within a few days of each other. Were the Macs purchased and put into service at the same time too? Two supplies gaking together is very strange - look upstream in your power chain for a blown surge protector, floating ground, etc. Don't just ignore this problem; other devices could be at risk! I removed the power supplies and was surprised to find that the power supply in the first computer I bought is an AcBel 400 Watt Rev B and the power supply in the second one I bought a few months later is an AcBel 360 Watt Rev A. Does anyone know why Apple used two different power supplies in two virtually identical G4's? Or which one is the better power supply? Did they have problems with the 360 W and replace it with the equally undependable 400 W? Apple didn't do anything other than give the contractor the specs from which to build the machine. That contractor probably ran out of the one supply and substituted another. Or perhaps the one with the bigger supply was built with video or extra HDs that required it? Could be many reasons. Either way, 40W is no big deal. There is an online service, National Ram Electronics, that repairs the AcBel G4 power supplies. Does anyone know if these bits of Chinese junk are worth repairing? Unless the repair is very simple and inexpensive, I'd just replace 'em. FWIW, - 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: MDD G4 Power Supply variations
I bought one MDD G4, found I needed a second one, bought the second one a couple or three months later. Thereafter I used them both, side by side, rather heavily. So both received virtually the same use and they are almost the same age. I put in new battery backups to address the possibilities you raised. Some have suggested that the 400 W power supply was brought out as a quieter system to address G4 noise complaints? I am considering scrapping these G4's because used power supplies on eBay are costing close to $150.00 with shipping. These power supplies have a poor service record and a used one is a risky investment. I presume that new ones are going to cost more than the G4's are worth? National Ram Electronics will repair G4 power supplies for $90.00 each and that seems to be the minimum cost to put the G4's back in service. === On Oct 7, 2010, at 2:11 PM, Dan wrote: At 1:22 PM -0400 10/7/2010, James Morgan wrote: I have a pair of Dual 1.25 MHz MDD G4's which have been my graphics workhorses since I bought them new. Recently the power supplies failed on them both within a few days of each other. Were the Macs purchased and put into service at the same time too? Two supplies gaking together is very strange - look upstream in your power chain for a blown surge protector, floating ground, etc. Don't just ignore this problem; other devices could be at risk! I removed the power supplies and was surprised to find that the power supply in the first computer I bought is an AcBel 400 Watt Rev B and the power supply in the second one I bought a few months later is an AcBel 360 Watt Rev A. Does anyone know why Apple used two different power supplies in two virtually identical G4's? Or which one is the better power supply? Did they have problems with the 360 W and replace it with the equally undependable 400 W? Apple didn't do anything other than give the contractor the specs from which to build the machine. That contractor probably ran out of the one supply and substituted another. Or perhaps the one with the bigger supply was built with video or extra HDs that required it? Could be many reasons. Either way, 40W is no big deal. There is an online service, National Ram Electronics, that repairs the AcBel G4 power supplies. Does anyone know if these bits of Chinese junk are worth repairing? Unless the repair is very simple and inexpensive, I'd just replace 'em. FWIW, - 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 -- 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: MDD G4 Power Supply variations
James Morgan wrote: I bought one MDD G4, found I needed a second one, bought the second one a couple or three months later. Thereafter I used them both, side by side, rather heavily. So both received virtually the same use and they are almost the same age. I put in new battery backups to address the possibilities you raised. Some have suggested that the 400 W power supply was brought out as a quieter system to address G4 noise complaints? I am considering scrapping these G4's because used power supplies on eBay are costing close to $150.00 with shipping. These power supplies have a poor service record and a used one is a risky investment. I presume that new ones are going to cost more than the G4's are worth? National Ram Electronics will repair G4 power supplies for $90.00 each and that seems to be the minimum cost to put the G4's back in service. Or you could convert generic ATX PSUs to work:- http://www.youtube.com/watch?v=xICg592xJTg HTH Ted -- 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: MDD G4 Power Supply variations
On 2010/10/07 12:11, Dan wrote: Unless the repair is very simple and inexpensive, I'd just replace 'em. Can MDD PSUs be replaced with a common ATX PSU with nothing more than a connector swap, or do they have a specialized output like the G3 iMacs did to power the sound? Tina -- iMac 20 USB 2, 1.25 GHz G4, 2 GB RAM, GeForce FX 5200 Ultra 64 MB DDR Power Mac June 04, 2 GHz G5 DP, 8 GB RAM, GeForce 6800 Ultra DDL 256 MB PowerBook G4 15 Hi-Res DL-SD, 1.67 GHz G4, Radeon 9700 128 MB DDR -- 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
