Can I use a 2011 27" iMac as a monitor for my newer Mac Mini

[philly019]

Can you use an old iMac as a monitor for a newer Mac Mini?

A client was throwing away an old 27" iMac. He gave it to me instead.
I believe it's a mid 2011 model. His repair guy said the logic board is shot & it's trash but it looks brand new physically.

The power light comes on, the screen flickers & I can hear stuff going on inside but the OS never launches. I assume the repair guy is right that the "motherboard is shot", but the display does seem to be work.

Can I connect it to a Mac Mini as a monitor? If so, how do I do that?

*** Please keep in mind I'm an old school graphic artist. I know how to use computers, not how to fix them or all the intricacies of how they work inside. Feel free to talk to me like I'm technically illiterate so I don't miss anything. I won't be offended. I just want to know if I should get rid of this machine or if there's some value left in the old thing. ***

 

[Sheepish-Lord]

Use your iMac as a display with target display mode - Apple Support

Target display mode is a feature available with certain older Mac models.

support.apple.com

 

[Juicy Box]

Can you use an old iMac as a monitor for a newer Mac Mini?

It depends on the year of the iMac and the year of the “newer” Mac Mini.

The Mid 2011 iMacs can be used as an external display using target display mode, but only with other Macs with Thunderbolt 1, 2, or 3, and excluding the M1 Macs.

If the free iMac ends up being a little newer, Late 2009 to Mid 2010 27”, they can be used with pretty much anything that has display port outputs, including M1 Macs and even PCs.

 

[Juicy Box]

His repair guy said the logic board is shot & it's trash

Target Display Mode requires the target iMac to be functioning, able to boot up and log into the OS.

Other solutions, like Screen Sharing, and third party solutions typically require the iMac to be working as well.

The power light comes on, the screen flickers & I can hear stuff going on inside but the OS never launches. I assume the repair guy is right that the "motherboard is shot", but the display does seem to be work.

The Late 2009 to Mid 2011 iMacs can fail from all sorts of reasons, but the two most common are failed HDD and failed GPU. There is a theory that the excessive heat from the HDDs with the lack of cooling might be the cause for the increased GPU failures.

The "motherboard is shot" could be a lot of things, and maybe not the whole logic board.

The HDD can be (relatively) easily replaced with a SSD if that is what the issue is, and the GPU can also be replaced, but requires the whole logic board to be removed.

Considering your admitted lack of technical skills, it probably wouldn't be worth messing with.

Myself, I collect old iMacs like that, use some for parts, and repair others for friends and family.