Two fried laptops later.

[Cap Erict3]

Originally Posted by chris95040

A few folks have posted how certain they are that the motherboard couldn't die without the brick also dying, but I disagree with this line of reasoning.



I'm an electrical engineer who designs consumer electronics for a living, but that's not even necessary to dispute this: The fact is we don't know how "beefy" the relevant items are - the power brick could have been up for the task, but the motherboard not.

What do you think once you add the potential from a collapsing field effect across all those little pn junctions?



Looking for another pretty place to work on the boat.

[Fuss]

Modified sine wave inverters cause uncertainty and also fry devices that are electronic.
I fried 2 electric tooth brushes,
change to a good quality sine w inverter.
unless you only want to run devices that are simple such as electric drills or hair dryers , change and remove the inverter uncertainty.
poor quality generators cause voltage spikes that damage devices.


Sent from my iPhone using Cruisers Sailing Forum

[Errantries]

Sorry for the delay in getting back to you folks. We are heading to the San Blas islands today, and preparations have taken over all our time.

We have decided to purchase small 300W pure sine wave inverter, and we’ve found a reputable marine electrician that we will have look over our system when we arrive in Panama. In the meantime, we’ll use the DC to DC car adapter plug to charge our one remaining laptop (borrowed from a friend).

socaldmax- yes, we have a MPPT solar controller, a flex max 80 from outback.

dauntlessny- the brick laptop charger will take 100v to 240v, 50-60hz. The usb plug was on a cigarette lighter type DC plug straight to the batteries.

CLady- I’m looking for reverse polarity. When I test positive to neutral I get ~110V, but pos to ground I get no voltage. No voltage from ground to neutral. Does this mean my ground isn’t connected? Erg. Very possibly gremlins.

Tx J - I agree that the iPhone explosion is likely a separate event. We aren’t around anything high powered RF wise, aside from the Icom 802 SSB, but we were not transmitting over it when the great sizzle of 2015 occurred.

chris95040- Thanks for your input on the brick-bypass. I agree that it seems like the brick could handle a spike and perhaps let some of it through to cook a more sensitive piece of equipment in the computer board. The two bricks that led to computer failure were 60W, and the one that hasn’t led to a fry is an 85W. Is that suspect?

Thank you all for your input. That helps so much. We’ll be off the grid for two weeks, but will post back when we get some insight in Panama. Cheers, and happy electrical gremlin hunting.

S/V Tayrona

[colemj]

Another possibility crossed my mind. Apple laptops use a magnet to connect their power cord to the computer. Is it possible that a small piece or hair of metal got attracted into the socket and bridged a couple of the pins?

Mark

[chris95040]

Originally Posted by socaldmax

Having posted that, as an engineer, what is your opinion of the engineering behind a power brick that could take a spike but destroy the laptop that it powers?

I have never been a fan of Apple products, but even I am not sure that they are built that crappy.

As an engineer, I'd probably design each component to be able to handle the expected, and some appropriate degree of unexpected, input. I certainly wouldn't (well, *couldn't*) design a power supply to win some arbitrary bake-off between the supply and the thing it's powering, in all bizarre scenarios that could possibly occur, because folks feel like the power brick should die first, no matter what.

I do agree with the sentiment of your post - in most scenarios, it feels like the power supply should be the one to die when there is some problem with the power source, and I suspect in most cases (that is, with most power source problems) it is. It also seems like MSW inverters are common enough that a device ought to be built to handle source "problems" of that sort, too.

All that's true, but what I said was that ruling out power-source problems because the mobo died and the brick didn't is not valid reasoning.

-Chris

[Cadence]

Originally Posted by chris95040

As an engineer, I'd probably design each component to be able to handle the expected, and some appropriate degree of unexpected, input. I certainly wouldn't (well, *couldn't*) design a power supply to win some arbitrary bake-off between the supply and the thing it's powering, in all bizarre scenarios that could possibly occur, because folks feel like the power brick should die first, no matter what.

I do agree with the sentiment of your post - in most scenarios, it feels like the power supply should be the one to die when there is some problem with the power source, and I suspect in most cases (that is, with most power source problems) it is. It also seems like MSW inverters are common enough that a device ought to be built to handle source "problems" of that sort, too.

All that's true, but what I said was that ruling out power-source problems because the mobo died and the brick didn't is not valid reasoning.

-Chris

[Looking4Neptune]

One question, probably too obvious - any possibility of lightening causing this?

Another thing strange - you say a number of iPad cables died. These are passive devices, just wires and connectors. It takes a REALLY big surge to damage those. But it does not take much corrosion. A little bit of salt water...

You might try a fine wire brush on the cable connectors.

[Cadence]

Originally Posted by Looking4Neptune

One question, probably too obvious - any possibility of lightening causing this?

Another thing strange - you say a number of iPad cables died. These are passive devices, just wires and connectors. It takes a REALLY big surge to damage those. But it does not take much corrosion. A little bit of salt water...

You might try a fine wire brush on the cable connectors.

And you didn't try to make it rocket science, just real life.