Broken pcb ceramic capacitor

Thread Starter

Steinarjm

Joined Jul 23, 2021
3
Hi, my motherboard on my laptop would not start after i change new ram, when i open it i could see a blown psb ceramic capasitor. You can see this in the photo. I removed it from the motherboard compleetly and made sure the line went to the other pcb. and changed to old ram, the laptop worked fine, but my quastion is how safe is this? Can i solder a new pcb from another old different motherboard thats the same size? Do all pcb ceramic capasitor have the same function since they are all alike? Am verry sorry if i posted this wrong, i am just worried what would happen and if someone here would be a kind soul to help me with all theese questions. 20210723_134430.jpg
 

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MrChips

Joined Oct 2, 2009
24,221
Ceramic chip capacitors may have the same size and look the same but they may have different capacitance values. We cannot tell the function of the capacitor without seeing the PCB layout and/or the circuit schematics.

Ceramic chip capacitors are rarely destroyed under normal operating conditions.
I have never encountered a bad chip capacitor.
 

ericgibbs

Joined Jan 29, 2010
13,640
hi St,
If the laptop works all OK without the cap, I would recommend that you don't attempt to replace it.
If in future you have a problem with the laptop get an engineer who has the required tools to
repair printed circuit PCB's.

E
 

Thread Starter

Steinarjm

Joined Jul 23, 2021
3
hi St,
If the laptop works all OK without the cap, I would recommend that you don't attempt to replace it.
If in future you have a problem with the laptop get an engineer who has the required tools to
repair printed circuit PCB's.

E
Thank you, i have tested the laptop in games and so on, it workes fine same as before. I was just worried. The laptop is old and i have 2 new once after this laptop, but just wanted to be sure.
 

Irving

Joined Jan 30, 2016
2,097
If you watch the youtube videos on repairing laptops/macs/iphones (try NorthridgeFix, Louis Rossmann, iPad Rehab) you will see that (after 'liquid damage') chip capacitors failing s/c is the #1 cause of a dead machine. In most cases they don't replace them, firstly because the value is unknown, and secondly because the vast majority are there to allow the device to meet EMC testing and are not needed for circuit operation.

If its working, consider it a good fix and leave well alone!
 

Ian0

Joined Aug 7, 2020
3,252
If you watch the youtube videos on repairing laptops/macs/iphones (try NorthridgeFix, Louis Rossmann, iPad Rehab) you will see that (after 'liquid damage') chip capacitors failing s/c is the #1 cause of a dead machine. In most cases they don't replace them, firstly because the value is unknown, and secondly because the vast majority are there to allow the device to meet EMC testing and are not needed for circuit operation.

If its working, consider it a good fix and leave well alone!
I'm just curious - how does "liquid" damage a ceramic capacitor? I worked in professional audio and lighting for 25 years, and have probably seen rather more than my fair share of "liquid damage".
 

narkeleptk

Joined Mar 11, 2019
540
I'm just curious - how does "liquid" damage a ceramic capacitor? I worked in professional audio and lighting for 25 years, and have probably seen rather more than my fair share of "liquid damage".
Probably shorts it or its circuit and overheats it?

I don't usually see them damaged either in the stuff I work on personally and I see a lot of liquid damage stuff come in. Most of the damage I run see is heavy oxidation on smd stuff causing poor/broken connections and/or decay at the via's.
 

MrChips

Joined Oct 2, 2009
24,221
From what I can see from the poor resolution photos, the capacitor in question is in parallel with another capacitor of unknown value across the power rails. These are power rail filter capacitors.

A 100nF chip capacitor across the power rail never hurts anybody.
 

Irving

Joined Jan 30, 2016
2,097
I'm just curious - how does "liquid" damage a ceramic capacitor? I worked in professional audio and lighting for 25 years, and have probably seen rather more than my fair share of "liquid damage".
I just re-read what I wrote, maybe it was confusing. Corrosion from liquid damage is arguably the #1 failure mechanism for equipment generally, but its a close run race with broken capacitors. High-value MLCC are not great mechanically and if overstressed can fracture through a combination of electrical stress, mechanical vibration/shock and temperature stress - the inside of a high-power laptop can be a harsh environment! I've seen quite a few where literally the end plating has just parted company with the bulk of the body.
 

Ian0

Joined Aug 7, 2020
3,252
I just re-read what I wrote, maybe it was confusing. Corrosion from liquid damage is arguably the #1 failure mechanism for equipment generally, but its a close run race with broken capacitors. High-value MLCC are not great mechanically and if overstressed can fracture through a combination of electrical stress, mechanical vibration/shock and temperature stress - the inside of a high-power laptop can be a harsh environment! I've seen quite a few where literally the end plating has just parted company with the bulk of the body.
Some of those MLCCs are so piezoelectric they can self-destruct due to mechanical resonance. If you connect the right frequency to them you can hear them whistle.
 

Thread Starter

Steinarjm

Joined Jul 23, 2021
3
I want to thank everyone for theire answare :) i did not expect so fast and many replys, i am really thankfull for it, now i can just hope the motherboard for the laptop will last some years more :)
 
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