MacBook Air M4 motherboard fried shortly after warranty expiration

I completely agree with @John Galt's assessment. Nothing the AASP said makes any sense. If an actual repair tech said that then I would be concerned about the tech's ability. However, if a front desk person said these things, then it is still a concern since they obviously do not understand the repair business. In that case, they should be reading the actual repair tech's notes, or asking the repair tech to speak with you about the details.

I would add that leaving your laptop off the charger for a week or so as you mentioned could have caused the battery to drain completely which is never a good thing. If the laptop was left powered on & asleep, then it is possible the battery drained completely. If you are going to leave the laptop unused for any length of time, then either completely power off the laptop, or make sure the power adapter is connected. An Apple laptop that is completely powered off may be able to survive on a fully charged battery for a few months, but I would not trust it longer than this. I have seen some Apple laptops needing charged again after being powered off for three months while others may be fine for six months.

If the battery remains completely drained for some time, then it can cause permanent damage to the battery. And especially with Apple laptops, a completely drained battery for just a few minutes can cause power on issues.

As one of our regular and respected forum contributors likes to say......your laptop is a battery capable device. Leave the laptop powered into the power adapter whenever possible. As long as the laptop is powered on & sleeping, then the Optimized Charging feature will make sure to exercise the battery to maintain battery health.

Also, sometimes I find some of these Apple Silicon Macs can get into a weird state where they may need to have a DFU Firmware Revive performed. I would never repair an Apple laptop without first trying a DFU Firmware Revive. I believe Apple has this requirement as well for their service techs.

If you have complaints about the AASP, then try speaking with the store manager. If still no satisfaction, then contact Apple corporate and let them know about your bad experience with that AASP.

Before you give up may I suggest another option: take that Mac to a different service center. The reason is that I am not impressed by what iVenus told you, for reasons beyond what they had to say about "constant charge" or "constant load" which as you suspect makes no sense.

A knowledgeable technician, one who respects you as their customer, would not refer to a "logic board" and "motherboard" as though they were two separate components. Choose one or the other, but there is only one such board, and Apple uses the former terminology.

Also, water damage is easily determined. It's not guesswork. Apple calls it "liquid damage" because water is only one such liquid. Other liquids are far worse.

Using jargon like "fried" is imprecise also, unless you were to immerse the logic board in a fryer, and fry it.

All this leads me to question if they know what they're doing.

Not impressed. Get a second opinion.

I would expect any reputable service facility to identify something specific, but that one just provided a number of possible causes. That is not a diagnosis. All they did was confirm something you already knew — broken Mac.

Potential reasons include a defective battery, which can be accomplished for a third of what they told you.

Either they don't know the cause, or they don't care to find out. You should get a definitive answer. If you were in the United States, an Apple Store would provide a definitive answer and propose a guaranteed solution, at no charge.

There are four possible solutions: get it fixed, buy a new one, both, or neither.

The technician gave me a reason that it might be under constant charge.

That does not make any sense. A Mac draws charging power when necessary, so you are correct — those reasons are not logical. Constant load, no load, in between, makes no difference.

Unfortunately these things happen sometimes without explanation.

While it is unlikely that the battery or charging would have caused the problem, it's possible. The failure of the magsafe LED to light may be an indicator there was a problem somewhere in the charging system; or simply that the logic board was in fact bad. There also are any number of other possibilities why the MacBook Air failed.

For the future, this is an example of why I consider it prudent to purchase AppleCare+ with a new Mac, especially a portable model. No one wants to see their computer go bad right after the warranty expires.

Thanks bro I was thinking about doing what you said.

But bro I mean you are not wrong but I am from India, and in India ₹60000 is about $640 ish US dollars(at current exchange rate) and i have to think twice before handing it for a full repair. I think I can get a good new laptop at that price range, like neo or something from windows. I came to apple community just for the answer that you gave should I just get another re-evaluation or not. Because the guys in community know more about terms and parts.

Thanks again I will just do that.