Surprise; Default Wallpaper and Super Slow

[halemano]

Aloha,

Early this morning, I turned on my 27" mid 2010 iMac and it is not the same iMac I turned off just a few hours before. It now shows the default El Capitan wallpaper, and it is so slow it is unusable. The spinning beach ball never quits spinning, the videos on my desktop never get to the thumb view, and web browsing is slower than first gen dialup.

This is an i7 2.93, 32GB Ram, 3TB HD.

When I purchased it off eBay years ago, the operating system was on a 256 SSD. It worked out of the box, but it was not my primary desktop, so it wasn't turned on for months (perhaps almost a couple years), and when I made it my primary, the SSD was nowhere to be found. I loaded Snow Leopard, and did all available upgrades, then wiped to clean instal Mavericks, which then was eventually upgraded to El Capitan.

Everything has been hunky dory for years, and the only issue is that my Adobe Creative Suit 5.5 Design Premium ED (also off eBay), which has run for years, was recently deemed invalid by Adobe and reverted to 30-day trial, which is not expired.

Couldn't get the system report page to load. Can't connect as 'shared' from another machine.

Just looking for suggestions on how to proceed; I would consider replacing both hard drives if that is the proper solution.

Mahalo for any help

 

[mikas]

There could be something wrong with either SATA connections, HDD and/or SSD, or the problem could be your graphics card aka GPU (Radeon HD 5750 1GB, I assume). All of these can make the machine crawl. Of course it could be a software and/or system corruption problem too, like some processes gone wild in background. Try to see activity monitor if there is something grabbing all the resources. These you can solve yourselves by installing a fresh system for example.

To the hardwares:
If you can manage to download and install MacFanControl, you could monitor iMacs inside temperatures and get a hint of what's going on inside. GPU could be hot. HDD could be hot. CPU could be hot.

You have used disk utility to see if the SSD is there? If not, maybe you should take it away, or at least check the cables. A loose cable can be a problem. Or if it's broken, maybe install a new SSD.

You can change the HDD an SSD, replace or reconnect the cables, reinstall everything and keep on going. You can renew thermal paste to CPU and GPU (and thermal pads too in case of GPU), but if GPU is burnt allready, I think replacing it is way too expensive. If it's the GPU, I would consider the iMac as parts to sell, or give away.

I don't think the CPU would burn very easily. But if so, it's perfectly replaceable in this model. I have done a i5 to i7 swap with mine. CPU thermal paste can dry though, and it would become a problem eventually.

Good Luck.