--- Jeff Walther <[EMAIL PROTECTED]> wrote:
> >Date: Tue, 6 Dec 2005 16:56:46 -0800 (PST) > >From: Nick <[EMAIL PROTECTED]> > >Subject: [q] Centris 650 Problems > > >I was hoping someone could give me some suggestions > >for a sick Centris 650. I had it in storage for a > >while and before I put it in, it worked great. > Once I > >took it out, however, I couldn't get it to turn on > at > >all. It appears to be dead. I can't get the fan > to > >come on or get a chime or anything. As far as I > can > >tell, everything is fine. I even pulled the SIMMs > to > >see if that would help. I also replaced the PRAM > >battery and nothing worked. At this point, I am at > a > >loss. > > >At any rate, I would appreciate any suggestions or > >tips anyone can offer me on getting this Centris > 650 > >back from the grave. I'd hate to scrap it as it's > a > >fine machine. There motherboard and power supply are perfectly clean. No dark stains. > Most likely the some capacitors in the power supply > or on the > motherboard have given up the ghost. Examine the > motherboard > carefully for a slightly dark discoloration around > the area where the > power supply plugs into the MB. If it looks like > there's a cola > stain on there, then your surface mount electrolytic > capacitors (look > like tiny silver storage tanks) have leaked their > electrolyte onto > the board. > > If the MB caps have leaked you could have three > problems. The > electrolyte is somewhat conductive and can cause > shorts. This is > corrected by cleaning the MB. Some folks run them > through the > dishwasher, but I recommend a careful scrubbing with > 91% isopropyl > alcohol (or spray with Flux remover and scrub). A > soft bristle or > worn out toothbrush is good for scrubbing. > > The electrolyte is corrosive and may have eaten > through traces, > solder joints or vias (conductive holes through the > motherboard) on > the motherboard. If this is the case, you would > need to identify the > damaged area and either resolder damaged solder > joints or bypass with > wire wrap (for damaged traces or vias). As far as I can tell, all the capacitors are fine. I have read about the "capacitor plague" but I think that's been more recent and has mostly effected PC hardware. The power supply circuit boards looke clean too. And even if I could just replace the caps, I have zero skill with a soldering iron. > There are about four of these caps that are > important to the power-on > circuitry. If those caps stop working, then the > machine won't stay > on. However, this problem more commonly has the > symptom that the > machine powers on for a moment and then turns off. > If these caps are > dead then you need to replace them. If you have > leaky caps, you > really ought to replace them all anyway, because > they could continue > to leak. If you use two 15W soldering pencils > (Radio Shack <$10 > each) it is easy to remove the surface mount caps. > Just apply one > pencil to each side and gently lift the cap when it > comes loose. I'm kind of looking for a no cost/super low cost solution as I'm a college student. Much of the Mac stuff I have is from Goodwill or sometimes people just giving their old stuff away. If I ever pick up a compatible power supply or motherboard I could plop those in. But I wouldn't want to gut a working Quadra just to revive a Centris. > Alternatively, your power supply may be history. > Again, the > electrolytic capacitors in the supply are the most > likely culprit, > but this time you'd be dealing with through-hole > caps rather than > tiny surface mount caps. Replacing the caps in the > power supply > might fix it. Do you know anything about the fuse? > You can use the power supply from the following Macs > in the Centris > 650: Mac IICX, IICI, IIvi, IIvx, Q700, C650, Q650, > PM7100. > > Motherboards for the Centris 650 are not uncommon on > Ebay and > generally under $15. You can also use the > motherboard from a Quadra > 650 or a Q800. Your CPU chip is almost certainly > still fine, so you > could even get a MB with no CPU and just move it > over, which might > save you a bit. I like the seller, Olde Mac Milt > (olde-mac-milt), > so you might contact him and see if he has a C or > Q650 motherboard > available. Thanks very much for your help. > Oops, just checked and it looks like he's in the > process of moving. > > Jeff Walther > > -- > Quadlist is sponsored by <http://lowendmac.com/> > and... > > Small Dog Electronics http://www.smalldog.com > | Enter To Win A | > -- Canon PowerShot Digital Cameras start at $299 > | Free iBook! | > > Support Low End Mac > <http://lowendmac.com/lists/support.html> > > Quadlist info: > <http://lowendmac.com/lists/quadlist.shtml> > --> AOL users, remove "mailto:"; > Send list messages to: > <mailto:quadlist@mail.maclaunch.com> > To unsubscribe, email: > <mailto:[EMAIL PROTECTED]> > For digest mode, email: > <mailto:[EMAIL PROTECTED]> > Subscription questions: > <mailto:[EMAIL PROTECTED]> > Archive: > <http://www.mail-archive.com/quadlist%40mail.maclaunch.com/> > > iPod Accessories for Less > at 1-800-iPOD.COM > Fast Delivery, Low Price, Good Deal > www.1800ipod.com > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- Quadlist is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! | Support Low End Mac <http://lowendmac.com/lists/support.html> Quadlist info: <http://lowendmac.com/lists/quadlist.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:quadlist@mail.maclaunch.com> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/quadlist%40mail.maclaunch.com/> iPod Accessories for Less at 1-800-iPOD.COM Fast Delivery, Low Price, Good Deal www.1800ipod.com
