Replacing an SMD Capacitor

[p55xp]

How can I replace an smd capacitor?
NOTHING IS WRITTEN ON IT?

 

[kchriste]

If it is damaged/faulty then you need the schematic.
The only other solution I can think of is removing one from another identical circuit and measuring it. ie: If the circuit was a stereo AF amp, you could look at the other channel for clues.

 

[Hero999]

Have a look at where it's connected, if it's across the power supply then it's just a decoupling capacitor so use 100nF rated to the supply voltage.

 

[p55xp]

Then I have to do this only by Guesswork.
I do not understand why nothing is written - at least some code?
Can you please explain the cause?
Is it a policy to achive producers' monopoly?

 

[DirtyLude]

We can't read the manufacturer's mind, but usually labels are only destroyed off of main chips to keep manufacturing secrets. Removing the label from a capacitor is useless because the capacity can be measured without difficulty if the product is working and people are just trying to reverse engineer it.

Likely there is no label because the part is too small or difficult to label, like a ceramic capacitor, or it's just really cheap and labelling just adds to the production cost.

Like mentioned, if it's in a specific part of a circuit, like decoupling a chip, or filtering right before/after an LDO it's not hard to make an educated guess.

 

[p55xp]

Mark,
SMD resistors are also cheap as well as small, - if your explanation is right then why it is marked?

 

[kchriste]

I do not understand why nothing is written - at least some code?

It could be because the parts are too small but more likely because of the material they are made of. Larger SMD capacitors are usually labeled, but the small ceramic ones are not.
Talking about SMD codes, here is a list of ones for semiconductors:
**broken link removed**

 

[DirtyLude]

Mark,
SMD resistors are also cheap as well as small, - if your explanation is right then why it is marked?

0402 resistors are not marked.

I said too small or difficult to mark, like mentioned above with ceramics.

 

[eng1]

Then I have to do this only by Guesswork.
I do not understand why nothing is written - at least some code?
Can you please explain the cause?
Is it a policy to achive producers' monopoly?

I think that the process of printing (and adding surface finish) to MLCC would result in more failures for the manufacturer / less reliability of their parts -> higher costs.
So, even if technically possible, marking MLCC might be avoided because of the more delicate properties of these devices.