If you see any leaking around the base or bulging at the top, they are definitely bad, though those bigger capacitors rarely leak, they just dry up inside. You can get replacements from Mouser, Digi-Key, Newark, or your local electronics supply place. Another thing to check is for bad solder joints on the same board. There are a few that are notorious and must have the solder wicked off and replaced with fresh solder.
On Mon, May 24, 2010 at 08:42:00PM -0700, Elliott Price wrote: > Ah, okay. That helps; It doesn't even chime, so I guess that means the > capacitors are bad. They looked fine, so I guessed that they were OK. > Is there another way to tell which ones are bad? I don't have an ESR meter... > Can you tell by looking, or with a volt-meter? Would it be best just to > replace them all? > In that case, where's a good source to get the right capacitors? I'm sure > there's tons of places online, but if anyone has recommendations for good > price, and good quality, that would be great! Thanks, > > > -Elliott Price > > Quoit - Macintosh Computer Services > hobbittech.com/quoit > > On May 24, 2010, at 8:37 PM, Ryan C. Underwood wrote: > > > > > They can be tested in-circuit with an ESR meter. The sound you describe > > is a typical failure mode of any switch-mode power supply. I have never > > run into a bad flyback that prevented the power supply from running, > > though I'm sure it's possible. All the bad flybacks I ever had caused > > focus/stability problems, acrid smell, etc. > > > > On Mon, May 24, 2010 at 08:23:36PM -0700, Elliott Price wrote: > >> Ah, that could well be the case. How can you tell which one(s) are bad? Is > >> there a way to tell for sure if it is the flyback, or the capacitors? > >> Thanks, > >> > >> > >> -Elliott Price > >> > >> Quoit - Macintosh Computer Services > >> hobbittech.com/quoit > >> > >> On May 24, 2010, at 4:44 PM, Ryan C. Underwood wrote: > >> > >>> > >>> If the clicking is rhythmic, and nothing else happens, it is more likely > >>> that you have dried up capacitors on the analog board that are > >>> preventing the power supply from coming up. > >>> > >>> On Mon, May 24, 2010 at 03:10:36PM -0700, Elliott Price wrote: > >>>> I have a Mac Plus that I'm pretty sure has a bad flyback transformer. > >>>> When you flip the switch, it makes a sort of rhythmic clicking, and > >>>> nothing else happens. I opened it up, and the flyback has white and > >>>> brown residue on it in certain areas. > >>>> Can you get new transformers? If so, where could I get one? Or is it > >>>> better to just get a new analog board? How hard is it to replace the > >>>> transformer? It looks easy enough to de-dsolder and then drop in a new > >>>> one. Are there any precautions to take to make sure it's fully > >>>> discharged? > >>>> Thanks, > >>>> > >>>> > >>>> -Elliott Price > >>>> > >>>> Quoit - Macintosh Computer Services > >>>> hobbittech.com/quoit > >>>> > >>>> -- > >>>> ----- > >>>> 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/ > >>>> > >>> > >>> -- > >>> Ryan C. Underwood > >>> runderwo(at)mail.win.org > >>> > >>> -- > >>> ----- > >>> 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 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/ > >> > > > > -- > > Ryan C. Underwood > > runderwo(at)mail.win.org > > > > -- > > ----- > > 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 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/ > -- Ryan C. Underwood runderwo(at)mail.win.org -- ----- 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/
