Electrical Gurus HALP

[tp4tissue]

I got a power board full of (ltec) capacitors.   They don't appear to be faulty visually.

but the board buzzes loudly.


You guys think I should replace them? preemptive-strike?

[tp4tissue]

aaagh.... just touched a big cap... finger numb..

this what i get for "feeling for bulge" (no-homo) without gloves

[Photoelectric]

Touching capacitors is as bad idea. You can damage/discharge them.

From what I understand, some capacitor buzz/whine is normal.  It can be audible or not very audible--depending on frequencies of induced vibration. Check out this basic article:

http://en.wikipedia.org/wiki/Coil_noise

But in general, so-called "coil whine" is common on high end graphics cards and some motherboards at certain processor power states.  It can also happen on monitors on their control boards (and some people have used epoxy glue over particularly noisy capacitors with some success to dampen the sound).

[tp4tissue]

Touching capacitors is as bad idea. You can damage/discharge them.

From what I understand, some capacitor buzz/whine is normal.  It can be audible or not very audible--depending on frequencies of induced vibration. Check out this basic article:

http://en.wikipedia.org/wiki/Coil_noise

But in general, so-called "coil whine" is common on high end graphics cards and some motherboards at certain processor power states.  It can also happen on monitors on their control boards (and some people have used epoxy glue over particularly noisy capacitors with some success to dampen the sound).

I am almost certain these were made in the era-of-the-capacitor-plague by ltec (taiwan) from the stolen electrolytic formula.

Now, I looked at the board more closely.

It seems the MAIN Power section is Nichicon.. that's good

The ltecs seem to be @ inverter section and what appears to be signal section.


Given this new information...it seems the H0t stuff is covered by nichicons, while the "mostly cool" stuff is ltec..


What do the Pr0s suggest given this new info..

[tipo33]

What do the Pr0s suggest given this new info..

Re-cap.

[dorkvader]

I am almost certain these were made in the era-of-the-capacitor-plague by ltec (taiwan) from the stolen electrolytic formula.

Now, I looked at the board more closely.

It seems the MAIN Power section is Nichicon.. that's good

The ltecs seem to be @ inverter section and what appears to be signal section.


Given this new information...it seems the H0t stuff is covered by nichicons, while the "mostly cool" stuff is ltec..


What do the Pr0s suggest given this new info..

Just replaced some bulging caps on a dell MB at work the other day.

Ok what sort of capacitors are these? Generally most electrolytics don't whine badly: that's usually an MLCC issue. If it's a PSU, it's much more likely inductor(s) or transformer(s) that are whining.

Capacitor branding probably isn't as much the issue here as what sort of capacitor they are and how they are being used. If the nichicons are physically hot, they might be higher specc'd units to withstand said heat. Then again, heat will cause electrolytic capacitors to fail quicker. It's hard to say for sure without more info.

[tp4tissue]

I am almost certain these were made in the era-of-the-capacitor-plague by ltec (taiwan) from the stolen electrolytic formula.

Now, I looked at the board more closely.

It seems the MAIN Power section is Nichicon.. that's good

The ltecs seem to be @ inverter section and what appears to be signal section.


Given this new information...it seems the H0t stuff is covered by nichicons, while the "mostly cool" stuff is ltec..


What do the Pr0s suggest given this new info..

Just replaced some bulging caps on a dell MB at work the other day.

Ok what sort of capacitors are these? Generally most electrolytics don't whine badly: that's usually an MLCC issue. If it's a PSU, it's much more likely inductor(s) or transformer(s) that are whining.

Capacitor branding probably isn't as much the issue here as what sort of capacitor they are and how they are being used. If the nichicons are physically hot, they might be higher specc'd units to withstand said heat. Then again, heat will cause electrolytic capacitors to fail quicker. It's hard to say for sure without more info.

the ltec, are in signal section, every thing on the board is 105*, but I don't think they're all driven that hot.

There is the white G00p on almost all the caps, they're all Low ESR from the spec sheet.. and I recall that low ESR tend to whine..

Of course there are inductors on this thing..  so ur saying it is more likely that the sound is "inductor whine"/transformer whine.