Will 3pin CPU fan plug work with 4 pins?

There were two of these Acer slimlines bought in the house at the same time (around $275 ea) but his had a fan as loud as a vacuum, which quieted down but became intermittent after he cleaned it. It improved after he took it off the heat sink to clean the nicotine (weight?) off the blades' other side. But it now sometimes needs coaxing to run.

His also has a dodgy vertical-mount DVD drive that never opened right and now requires a paper clip to open. I wanted to order him a new $20 SATA DVD drive and fan but he doesn't want to spend the money on it.

The other one runs perfectly except for a periodic white-screen crash I'm troubleshooting.

gregrocker said:

So the urgency has greatly diminished to leaving a link on his desktop, probably this one y'think matching the exact P/N? Acer HI.10800.028 Heatsink and Fan Gateway AX3400G X1420G X1920G

The issue I see with that one is it's used...
No telling how long it will last - guess it's just a gamble.
I don't like to buy used/refurbished, especially if there are moving parts...

Good point. I'll keep looking for a 95mm fan with 4 pin plug.

My replies/comments are in blue.

gregrocker said:

There were two of these Acer slimlines bought in the house at the same time (around $275 ea) but his had a fan as loud as a vacuum, which quieted down but became intermittent after he cleaned it. It improved after he took it off the heat sink to clean the nicotine (weight?) off the blades' other side. But it now sometimes needs coaxing to run.
That's bad and can easily and quickly cause overheating, shutdown, hardware damage...
I had the same issue with the GPU fan i mentioned...

His also has a dodgy vertical-mount DVD drive that never opened right and now requires a paper clip to open. I wanted to order him a new $20 SATA DVD drive and fan but he doesn't want to spend the money on it.

Would he consider an external DVD drive, so more $ are not spent upgrading an old machine?
Then the drive could easily be used on "any" PC.

I understand, at some point it doesn't make sense to spend more money maintaining old technology.
Just have to bite the bullet, buy new, and move on.

The other one runs perfectly except for a periodic white-screen crash I'm troubleshooting.