Ceramic Caps and dead short to ground

Ceramic Caps and dead short to ground | Minix Neo X5

I love watching videos about reapiring electronics and common problems in this video are faulty ceramic capacitors.This little guys usually sit between Vcc line and ground used as a filter caps.
This is great for smoothing voltage rails, but the problem comes up when this caps are failed and causing a dead short to ground. Your device will immediately turn off and never come up again.
My Minix Neo X5 had a same problem when I bought it.
After I opened up I see somethink strange, somebody tried to fix it by upgrading the fuse just like Tesla Motors did in they batteris. Probably he spend years to researching the right material for this job :D

Shorted Fuse

Detecting the problem was easy, same as in my previous post about A31s android tablet.Some measurement on diode mode and clear to see that we have a shorted a rail.You can find the WM8326G datasheet online and usually this datasheet including a reference schematics.This is a good way to start discovering your device subsytem.After you identifyed the power rails you can measure one by one.If you measure fairly low voltage drop between ground and Vcc you probably found the shorted voltage rail.

Next you have various way to detect the failed component.I used the heating method.I desoldered the inductor so I isolated the PMIC and the rest of the board. After I injected some power intro this voltage rail, shortly come up the faulty part because it is driving all the current to ground and this is generating a lot of heat (the shorted part can blow up if you apply to much current).

In my case this cap was bad behind the inductor.

The lower desoldered cap was shorted

As you can see I desoldered 2 caps.The faulty cap was shorted so I can't measure its value so I removed one from a fairly same rail and I measured that.

A bit of dumpster diving I get the right replacemnt cap, I put it together and plug in.

My Minix was booted happily so time to streaming my series.

More pictures about the Minix

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