Electronics > Repair

LNK305 and the likes mass dying... any reason for it?

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Neutrion:
So there are plenty, mostly consumer equipment where this, and similar parts are used, and they seem to be dying in such a huge masses, that for washing machines there are complete kits with fuse resistor, etc, including this IC  aviable to repair the boards.
Of course most of the boards are never get repaired.
Different appliance manufacturer are affected from different years, and these ICs are failing seemingly in a very short time, usually shortly after the warranty period is over.
What is the cause? I could not found any good explanation to it anywhere on the net. 
None of the manufacturer is able to properly mount it to give it a proper cooling? (It even has overtemperature protection.) Voltage spikes?
Bad batches of the parts?
It causes such a huge amount of equipment failures, that possibly tens of thousand tonns of waste is produced yearly only because of them.
And no, its not made by Apple, but it would fit well into their concept  >:D

BrokenYugo:
You're probably right, too hot or not enough protection. Just the usual penny pinching.

Keep in mind overtemperature protection is generally set closer to "Guaranteed to not desolder itself!" than "Will last a long time bouncing off the limit".

Also, aren't most of these appliance brands largely under the ownership of 2 or 3 companies now? This may even all trace back to a single design mistake that was simply never corrected.

Kerlin:
Well ..... imagine you bought some things from someone who hates you, would you really be surprised if they often went faulty?

Neutrion:

--- Quote from: BrokenYugo on October 25, 2021, 07:10:21 pm ---You're probably right, too hot or not enough protection. Just the usual penny pinching.

Keep in mind overtemperature protection is generally set closer to "Guaranteed to not desolder itself!" than "Will last a long time bouncing off the limit".

Also, aren't most of these appliance brands largely under the ownership of 2 or 3 companies now? This may even all trace back to a single design mistake that was simply never corrected.

--- End quote ---

If the design uses the part within its rated consumption, it should run way below the overtemp limit, and basically should last forever, especially as the IC has - in a case of a washing machine which is 1-2 yeas old - only 1-2000 working ours with the part working hard.

So either non of the manufacturer is able to solder the part in with its base properly connected to the board, or the something is not well documented in the ICs documentation regarding its surge protection.

But how can it be, that this broblem is ignored by almost all of the manufacturers for years?

amyk:
These single-chip SMPS ICs seem to be pretty fragile especially to voltage surges.

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