Jump to content
HWBOT Community Forums

0402 Capacitor Values under 12900K IHS

Recommended Posts


This is a long shot, but does anyone know the capacitor value for the tiny 0402 capacitors on the 12900K under the IHS?

I am also wondering if the function of these capacitors is known. They look small for decoupling to me.

I stupidly knocked them when delidding as a shaving of the silicone I was removing hid them - turns out my eyesight is not what it used to be. I think I have stared at one PCB too many!

Here's a photo of the capacitors. I have surface mount tools, so should be able to get them back on, but I only have one of the two. I did have both, but a little too much tension in my tweezers and the little critter launched itself like a flea, never to be seen again.

If anyone knows the value or function then great. If not, I'll try to measure the remaining one with a capacitance meter and post back here.

Thank you @der8auer for your excellent delid video, so I can get the orientation right when I put them back... hopefully! Your comment of 'Good luck putting those back on if you knock them off' has made me kick myself several times, especially since I watched your video twice before attempting the delid myself! ?


12900k Delid.PNG

Link to comment
Share on other sites

So, based on my measurements, I reckon these capacitors are 33pF (Pico Farads).

I measured the capacitance of the one that remained (the one I didn't lose!) using a cheap LCR meter that I got from Amazon. I had to calibrate this meter+leads off some known capacitors I had hanging about.

I will order some replacements and see how it goes.

Here's a photo of the capacitor I knocked off next to a standard ceramic capacitor of the same value, to give an idea of size - I have never handled SMT components this small before. Incredible!

I haven't pinned out the CPU to work out what they are connected to. I would do this, but I would need to solder onto the pad, which risks damaging the tiny area before soldering replacement capacitors back on. As there's a pair and they are very small values, I don't think they will be decoupling, I reckon they will relate to a differential bus of some sort - part of a PCIe lane perhaps, I don't know. I think I should put them back!




  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...