After washing it it still only shows the gray screen. I got two SCSI 50 pin hard drives coming in the mail and I am in the process of getting capacitors, the 6500 post is about that. So I guess we will see what happens after those.
I will also have two more Mac classics as I have some of them that need their capacitors changed so I needed capacitors anyways, probably won't hurt to recap the other computers either. > On May 15, 2015, at 12:27 PM, Jeff Walther <[email protected]> wrote: > > > >> On Thursday, May 14, 2015 at 4:05:32 PM UTC-5, Violet Cloud wrote: >> Hmm, well it worked once but didn't see the hard drive during installation. >> >> Now it won't boot with the floppy or cd at all and will only go to the all >> gray screen again. >> > > I would remove the logic board, remove any RAM, etc. and thoroughly wash > the board. Many methods are viable. I prefer to spray boards with flux > cleaner, give them a gentle scrubbing with an old tooth brush, rinse with 91% > isopropyl and then rinse with distilled water. Just washing (scrubbing) > with the isopropyl and skipping the flux cleaner works pretty well too. > > The idea is that the surface mount electrolytic capacitors (look like tiny > silver fuel storage tanks) have leaked corrosive, mildly conductive goo onto > the logic board. The caps probably need to be replaced, but a servicable > interim test which usually works is to thoroughly wash the board. If it > works properly after that, then you've stopped any immediate corrosion, you > have a (temporarily) working board, and you know that the capacitors > definitely need to be replaced. > > The leakage from the caps is extremely hard to see. It looks a bit like old > dried cola, a slight brownish discoloration and is more visible if you view > the board at an oblique angle to a light source. Sometimes you'll find dust > stuck in the tacky leakage adn that can make it easier to spot, but dust does > not always accumulate on the leakage. > > Pretty much all the 840AVs out there need their capacitors replaced at this > point. It's probably true of their little brothers, the 660AV, too. > > BTW, if the 6100 was missing its ROM it would not make a sound at boot up. > If you're getting a good chord or even chimes of error/death, that means that > a ROM must be present. Not really relevant any more, given how things > turned out, but might be useful to know later. Also, if you start getting > mysterious crashes after running for a while, on the 6100, there's a fair > chance that the heat sink grease between the CPU and heat sink has turned to > powder and needs to be replaced. > > Given time, such leakage will corrode logic board traces, vias, solder and > component pins. > > Jeff Walther > -- > -- > ----- > You received this message because you are a member of the Vintage Macs group. > The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our > netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml > To post to this group, send email to [email protected] > To leave this group, send email to [email protected] > For more options, visit this group at > http://groups.google.com/group/vintage-macs > > Support for older Macs: http://lowendmac.com/services/ > --- > You received this message because you are subscribed to the Google Groups > "Vintage Macs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- -- ----- You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To leave this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/ --- You received this message because you are subscribed to the Google Groups "Vintage Macs" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
