iMac late 2009 stuck/random freezes

[Oder]

Hi Guys,

Upgraded an old iMac10,1 (late 2009) with an SSD replacing the CD drive using a caddy. But after a while the computer gets stuck on the loading bar, sometimes it passes and can access desktop but when it happens most of the times the computer freezes and only mouse works. Also noticed the SMC version is 1.52f9 so not updated to the latest version 1.53f13, cant see if ROM version is updated cause its not listed on the Apple site.

Also found this thread that discusses the issue and one of the solutions provided was to enable trim, that was done but the problem still persists.

Maybe the problem is related to a faulty GPU?

OS is High Sierra with all the updates.

 

[Certificate of Excellence]

Do the issues still persist if you return the machine to its stock hardware config? If not, that points IMO to the added SSD/super drive caddy. I noticed that there were a few folks on that thread you linked to that completed the same mod and and were experiencing the same sort of freezing yet none (that I saw) stated if they returned the machine to stock config and if it fixed the issue.

I wonder what verbose mode says.

 

[theMarble]

If you're willing to disassemble the iMac, I would try fully removing the second SSD/CD Drive caddy and booting the system without it plugged in. Then, you'll know whether it is the caddy or something else. Otherwise, I'd try reinstalling the OS as it sounds like it might be OS related too.

 

[Oder]

Thank you for plugging in, so first will try to install High Sierra on the original spinning HD to see if it behaves normally, if that also fails will then disassemble the iMac and remove the SSD/caddy drive. Will report back.

Could the problem be that the SSD is formatted in APFS?

 

[Certificate of Excellence]

I wouldn't think so. APFS was designed with SSD technology in mind - to maximize the benefits of flash storage. IIRC with Hisi, the installation boot drive is automatically formatted as APFS. Anyhow, I don't think that would be the cause of the issue.

Now I have read that APFS causes fragmentation on platter and fusion bootdrives causing slow performance and instability. Is your boot drive a spinner or SSD?

 

[Oder]

I wouldn't think so. APFS was designed with SSD technology in mind - to maximize the benefits of flash storage. IIRC with Hisi, the installation boot drive is automatically formatted as APFS. Anyhow, I don't think that would be the cause of the issue.

Now I have read that APFS causes fragmentation on platter and fusion bootdrives causing slow performance and instability. Is your boot drive a spinner or SSD?

Thank you for the tips about APFS, right now im considering everything to make it work but think will have to send it for repair as its out of my knowledge now.

The boot drive is SSD, the original spinning HD is used for backups. Yet to try installing OS on the original drive to see if the problem persists.