AC ADAPTER replacement. Which numbers matter?

ac adapter for my ancient msi laptop is failing with major coil whine, making the motherboard squeal too.
It's a 65w adapter, 19v x 3.42 amps

ac adapter for my prehistoric dell laptop is 90w, 19.5v x 4.62amp

can I use the 90w adapter with my msi laptop? slightly higher voltage and amperage is ok?

 

The higher amperage is definitely ok. Voltage wise, 0.5 V extra should be ok, but ideally, you'd want a voltage that matches your previous adapter.

 

You could try asking MSI, they may even send you a new one for free - it's happened before.

 

nah, it's over 7 years old. they're not giving me anything for free.

i just bought a cheap pin adapter off ebay so i can use the dell adapter with the msi.

 

You probably already know about the MSI parts ordering place, but here it is, just in case

https://shop.msicomputer.com/App/StoreFront/ProductDetail.aspx?ID=1481

https://shop.msicomputer.com/App/StoreFront/ProductSearch.aspx?CRITERIA=AC+

 

Not something I would do-asking for problems. Pin plug will be not a match causing arching inside the plug itself causing unstable power. Also as other mentioned Voltage must be the same or slightly higher but Amp must never be lower then the OEM charger otherwise expect a charger that will be hot and possible fire hazard. Never think a Dell will work for MSI with adapter one should do the smart and right match not thinking one can mix and match and think it will work also doing so if that causes your laptop damage that you will not see. Getting a OEM matching charger isn't that expensive even on eBay-so do the right way not the wrong way.

 

nah, i measured the voltage with a multimeter.

Even though the dell says 19.5v, it measured identical voltage as the cheap generic "li shin" charger supplied by msi.

the msi charger says 19v, but measures 19.5v.

Also, Dell sells pin adapters themselves for rip off pricing.
https://www.amazon.com/Dell-7-4mm-4-5mm-Power-Dongle/dp/B01JRHCFWW

The pin adapter I bought is an exact size match for the msi charging port, and only cost a little over $1.

I'll measure with a voltmeter to see how stable the voltage is plugged into the pin adapter.

 

You also have to make sure polarity is correct too. Stick to the original model and make AC adapter if possible.

 

I agree. I'll pay the extra for genuine AC adapters. Cheap ones are well known to die out and/or fry your electronics because of voltage fluctuations.

 

This is a Dell original, so it should do just fine. Especially considering it is vastly oversized for the 65W device it'll be powering. Polarity is an important item to check, but I've yet to see a laptop adapter that wasn't center positive. Doesn't hurt to check the symbols on the stickers or verifying with a multimeter, of course.

Mind that 'generic' or 'universal' ≠ bad adapter. Though too-cheap-to-be-true is a different matter, to be sure, but you can also find used originals for very little and a cheap adapter plug will go a long way. Bit of an old article, but very good, detailed information and little has changed since then (it also deals with voltage ripple):
Round-up of 74 laptop power adapters: original or universal?

 

there is no polarity symbol on my dell nadp-90kb ac adapter, but judging from the generic replacements for it, the polarity matches the MSI adapter's.

Also, oem dell adapter is made by Delta, compared to the cheap MSI adapter made by Li Shin. I have no worries.

I have never had an ac adapter make the whole laptop motherboard squeal loudly when plugged in. That's a new experience.

Just by luck, my lenovo Y580 ac adapter fits the MSI laptop, and the squealing is gone.

 

Dell have used Flextronics adapters as well. Not only Delta.