gluing capacitors in the power supply

[bigmessowires]

I've finished replacing all the capacitors in my Mac IIci power supply, now I'm wondering whether I should glue the new capacitors in place. Many of the old capacitors were glued in, which I understand can help prevent high-frequency whining noises, but the glue also made it a pain to remove the old caps. If you've recapped a PSU, did you glue in the new capacitors?

 

[David Cook]

I have recapped a lot of SE, SE/30, and LC-series power supplies without applying hot glue. I feel guilty about it. So, I'm not looking forward to the responses to your topic.

 

[Byrd]

I've been recapping like crazy lately and wouldn't bother with hot glue unless the capacitor does emit noise (yet to see/hear) or of the cap is in a precarious position, eg. you have to use a slightly bigger/wider one and it's close to some other component. Another reason might be if there is a fragile trace and you need it so stay put to avoid damage from movement.

 

[cheesestraws]

I'd have thought it would mostly be inductors that would whistle, since most inductors want to be loudspeakers when they grow up.

I tend to apply glue when the capacitor is bent over, or when I don't think the legs are supporting it properly, but I'll freely admit that that's more cargo culting than engineering, and it'd probably be fine without.

 

[joshc]

Glue them! If not only because hot glue is fun! People who have seen me use it can attest to my love for it.

On a slightly more serious note, it should be absolutely fine without it - but may help if there's any capacitors that feel a bit loose or have to be bent or positioned in a strange way.

 

[Mk.558]

A number of capacitors in that power supply are a bit on the American side and can put stress on their solder footpads if they move around. This is generally considered by many to be an undesirable situation. I'd glue any that were glued from the factory or are a little loose.

 

[LaPorta]

A number of capacitors in that power supply are a bit on the American side and can put stress on their solder footpads if they move around. This is generally considered by many to be an undesirable situation. I'd glue any that were glued from the factory or are a little loose.

What is the American side?

 

[LaPorta]

I've finished replacing all the capacitors in my Mac IIci power supply, now I'm wondering whether I should glue the new capacitors in place. Many of the old capacitors were glued in, which I understand can help prevent high-frequency whining noises, but the glue also made it a pain to remove the old caps. If you've recapped a PSU, did you glue in the new capacitors?

If there was glue, I generally replace it. I especially do this if the caps are the long, barrel type electrolytics and are placed 90 degrees from vertical.

 

[joshc]

What is the American side?

BIG, YUGE, ETC.

 

[LaPorta]

Haven't heard that one! I certainly do not fall in that range as an American.

 

[zigzagjoe]

IMO there isn't a huge need to reapply the silicone glue.

 

[jmacz]

Like @joshc I have only hot glued caps if I feel like they could use some more support.

I have heard folks put glue on the inductors to help with whine, but I don’t think I have ever had this work to eliminate whine on old PCs.

 

[Phipli]

I'd have thought it would mostly be inductors that would whistle, since most inductors want to be loudspeakers when they grow up.

I tend to apply glue when the capacitor is bent over, or when I don't think the legs are supporting it properly, but I'll freely admit that that's more cargo culting than engineering, and it'd probably be fine without.

Caps sometimes whine too, but I haven't had it with anything freshly recapped. I wonder is it cheap parts or the age into it.

I tend to gunk what was gunked before. Lightly, in case I want to remove them.

Interesting fact for removing gunk - IPA dissolves silicone and makes it come off more easily.

 

[joshc]

I usually desolder the caps, and then I get relatively agressive with a pair of pliers to pull them off, along with the hot glue. Most hot glue can be detached from whatever its attached to without too much effort.

I'm more careful if said glue is attached to something like an inductor coil where that part won't be as easy to replace...

If it's just caps connected together with glue, my trick above tends to work well.

 

[Phipli]

I usually desolder the caps, and then I get relatively agressive with a pair of pliers to pull them off, along with the hot glue. Most hot glue can be detached from whatever its attached to without too much effort.

I'm more careful if said glue is attached to something like an inductor coil where that part won't be as easy to replace...

If it's just caps connected together with glue, my trick above tends to work well.

I find sometimes they stick them to the transformer and I don't want to pull on the insulation too much.

 

[stepleton]

I usually desolder the caps, and then I get relatively agressive with a pair of pliers to pull them off, along with the hot glue. Most hot glue can be detached from whatever its attached to without too much effort.

You don't have to be too aggressive with hot glue. Hot glue has a natural enemy: the propes.*

(* Isopropyl alcohol.)

 

[bigmessowires]

I chose to skip the glue based on the feedback here, and I don't think I hear any whining, or maybe I just can't hear high-frequency sounds anymore. This was my first full recap of a PSU so I was a little nervous. The PSU was working OK before, but I chose to recap it to help keep it that way for years to come. Post-recap I'm measuring 5.08V, 12.17V, and -12.13V. I also replaced the PSU fan with a similar but new one, since the old fan was making unpleasant noises even after oiling the bearing.

 

[Juror22]

Glue them! If not only because hot glue is fun! People who have seen me use it can attest to my love for it.

I'm not sure if I am going to glue any, but this swayed me further than any other opinion! I need to dig out my hot glue gun!

 

[tt]

I'm guessing the glue was also for shock and vibe in shipping and moving around the machine.

 

[JC8080]

A number of capacitors in that power supply are a bit on the American side and can put stress on their solder footpads if they move around. This is generally considered by many to be an undesirable situation. I'd glue any that were glued from the factory or are a little loose.

"on the American side" - thank you for that, that made me smile.