I'm guessing these PSU caps have had it?

[MikeHunt79]

I fitted an IEC socket to my Numark SA3000 today, and saw this:


The amp works fine, but I'm guessing it would work better if I put some new caps in?

The existing ones are 3600uF, while my replacement ones are 4800uF, all 80V.

Higher capacitance should be fine for PSU caps tho should'nt it?

I just want to check before breaking out the soldering iron.

[dave_gerecke]

Hey Mike, The increase in the cap value should be fine, might even clean the supply up a little more. Those caps do look at wee bit stressed. Kind of like I felt today. Even if the amp works now, they look likely to burst and then it makes a big mess and usually stinks. Good luck and have fun!

Peace,

Dave

[whoandcar]

Man, there is gas developing pressure in the interior of those aluminum cans. They eventually will explode, leaving toxic fumes and a white oilish substance casting all around.
Replace them as quick as you can.
Not to scare you, thou!

[poynton]

I'd love to see the picture but something seems to have happened to it.

Andy

[djQUAN]

Originally posted by poynton
I'd love to see the picture but something seems to have happened to it.

Andy

same thing here.


before you replace the caps, power the amp and meaasure the rails if they go above the voltage rating of the cap. if so, replace with a higher voltage one.

[MikeHunt79]

Originally posted by poynton
I'd love to see the picture but something seems to have happened to it.

Andy

Imageshack seem to have lost the pic, so I re-uploaded it:



I've now replaced them, and the amp is working fine:



I have no idea how old this amp is as I bought it used, but there was so much dust in there, I've got most of it out now. The originals were actually 3300uF, and there's now 4700uF caps in there.

I haven't measured the rail voltages, but I will next time I have the lid off. The original caps were rated at 80v tho.

EDIT: The caps had already started to leak, I had to wipe some of the brown stuff off the PCB:

[poynton]

It is quite common for caps with the plastic top-cover to appear to bulge.

If you remove the top plastic piece, is the case bulging ?

The brown stuff on the pcb is anti-vibration glue, commonly used.
Having said that, I cannot tell from the photos if the caps are leaking as well or not.

Andy

[Bigred]

Originally posted by poynton
It is quite common for caps with the plastic top-cover to appear to bulge.

If you remove the top plastic piece, is the case bulging ?

The brown stuff on the pcb is anti-vibration glue, commonly used.
Having said that, I cannot tell from the photos if the caps are leaking as well or not.

Andy

Clearly those caps sh*t the bed.

[AKN]

Hi,

Quite easy to push the plastic bulge i order to feel if there is solid aluminum underneath.

[MikeHunt79]

* goes and grabs caps from bin *

Originally posted by poynton
It is quite common for caps with the plastic top-cover to appear to bulge.

If you remove the top plastic piece, is the case bulging ?

Yep:

Originally posted by poynton
The brown stuff on the pcb is anti-vibration glue, commonly used.
Having said that, I cannot tell from the photos if the caps are leaking as well or not.

Andy

Both goo's are brown, but the light brown (glue) is soft and squidgey, while the dark brown stuff (electrolite?) is dry and had to be scraped of the PCB:


They're going back in the bin now, unless they have to be disposed of in some special way?