I just installed a memory chip in my wife's computer, an Acer Inspire. Upon turning it on it started making a whine noise, like some kind of alarm. Not real loud but it wasn't there when I turned it off.
Any ideas what it may be? Would the computer do this if the memory wasn't compatible?

I found the problem. I checked the part numbers against the computer spec sheet and found that the 16 GB memory stick they sent me (and got the Acer part number for, from the Acer tech) was wrong.
The computer only allows a max of 8 GB memory- so the motherboard gagged on it.

The Acer tech was an orangutan.

Wire touching a cooling fan or cpu?

No. I removed the new memory and the sound went away; reattached the memory and the sound returned.
I'm thinking that it's an alarm about a faulty memory module.

did you remove the old RAM and replace it, or just add another RAM stick?  If the second, are the two RAM modules the same speed?

And did you confirm the new RAM is compatible with the MB, etc?

I added another ram stick. I talked for several minutes to an Acer tech who assured me that it was compatible with the computer.

Check the trouble shooting section of the manual.

Often they have a detailed chart showing the meaning of the alarm.

And as dumb as it sounds, look for "board model" plus "beep" on youtube. Then check the comments of any video that has your sound.

Specs on the old RAM, new RAM, and the motherboard?

For issues such as bad video cards, memory, etc., PCs use beep codes to signal what is wrong. They are actual beeps though (you have to count them), not just a sustained whine. Aside from that, a couple of caveats on memory upgrades. MOBO manufacturers specify in the board documentation what combinations of RAM sticks will work, and which slots to use if not using ALL. Also any specification for pairing or matching the sticks. That's what you need to suss out first - ensure your exact configuration, to include which sticks are in which slots, meets the specification in the manual.

From the Acer XC380 documentation:

Here’s a quick guide to interpreting beep patterns:

Beep PatternPossible Issue
One short beepNormal POST, system okay
Two short beepsPOST error, review screen
Long continuous beep tonePower supply or system board problem
Repeating short beepsPower supply or system board issue
One long, two short beepsVideo card malfunction
Three long beepsKeyboard control failure


So installing one stick of ram has caused a power supply or system board problem?



Could chip speed/parity/whatever do this?

I replaced the chip with one with the same part number from Acer.