News Some Asus Z690 Hero Motherboards Have Melting MOSFETs, Theory Proposed

InvalidError

Titan
Moderator
Definitely looks like people in the supply chain failed to note or notice that capacitors on some reels were the other way around.

In principle, this should have been caught by the pick-and-place machines' visual inspection. Parts markings and orientation verification have been around for a very long time.
 

Alvar "Miles" Udell

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Apr 1, 2020
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If not caught by automated means, it should have been caught by QC. The ironic thing is that ASUS is marketing an AI quality control inspector to prevent manufacturing errors like this without the need for human based QC.

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ASUS Keeps an AI on Quality Control in Smart Manufacturing

Automating quality control on production lines improves defect detection and ensures continuous operations. A customized automated optical defect detector leads one hardware vendor to build a software development kit to help system integrators improve their clients’ manufacturing processes.
 

NightHawkRMX

Polypheme
Ambassador
I am growing more and more confident that ACTUAL QC does not exist anymore for computer parts. Things like this make me more and more confident. The Acer monitors that explode promptly after being plugged in are another example. Shows they never even plugged them in at the factory.

You can't just do a visual inspection of a PCB to see if something works or is even safe to operate.
 
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InvalidError

Titan
Moderator
You can't just do a visual inspection of a PCB to see if something works or is even safe to operate.
Well, a backwards polarized capacitor can "work" for hours before blowing up depending on how high the reverse bias voltage is vs rating, chemistry, construction, etc. and wouldn't be caught by something like post-assembly bed-of-nails testing that only lasts a few minutes.
 

InvalidError

Titan
Moderator
Mine is also backwards like the drawing, so far no issues though.......
Point an IR thermometer at it if you have one. Backwards polarized capacitors usually get pretty hot pretty quick. SMD capacitors installed the right way around should be about the same temperature as the board around them since the bulk of whatever little heat they generate gets sunk into the board.

If the capacitor's temperature is significantly hotter than everything else around it, then failure is only a matter of time.
 

Alvar "Miles" Udell

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Apr 1, 2020
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Mine is also backwards like the drawing, so far no issues though.......
If your motherboard serial number matches those in the recall you better send it back. Even if it is properly installed with proper polarity and just labeled backwards, it's technically illegal to resell it as it's a recalled product, plus there is no reason to chance it.

Yes it's a pain in the butt to change a motherboard out and especially to be without a computer for a while if they won't cross ship, but there's no reason to take a chance on it, plus you can use the excuse to change cases or upgrade your cooler. To quote ASUS:

The issue potentially affects units manufactured in 2021 with the part number 90MB18E0-MVAAY0 and serial number starting with MA, MB, or MC.
 

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