Problems with Chrome and Safari + disk errors

[carrotflowers]

I have a refurbished 2010 Macbook Pro 13" running OSx 10.10.5. It got significantly slower after upgrading to Yosemite, and then about 2 months ago I started having seriously strange issues.

First, when using Chrome the screen scrambles--the window breaks up into tiles which shuffle around with or without moving the cursor. And then when I use Safari, and every website I try to go to triggers a notification that the "Server identity could not be verified" and clicking "Continue" does nothing, the notification just pops up again. After quitting the browsers, they can't be relaunched--clicking the icons does nothing.

Lastly, a few times I have tried to save documents (from Photoshop and the Stickies app) only to be told there was a disk error and files could not be written.

I've run a virus scanner, rebooted in safe mode, reset the automatic date & time, but nothing has fixed it. It seems to crop up randomly, and only goes away after restarting several times but even then it always starts up again eventually.

Any insight into what could be causing this?

 

[honestone]

First, have you been making any backups to an external device?

Regarding your refurbished machine, what was done to it to make it available for sale? If the internal disk drive was not changed, that could be a possible issue, as the drive would be more than 5 years old, and thus might be coming to the end of its usable life.

Another possibility is that you have disk issues that can be possibly be repaired. There should be a hidden Recovery Partition on your drive. What you can try is when you boot up your machine, hold down the Command and R keys. This link has information about what that partition can do:

https://support.apple.com/en-us/HT201314

You would want to use verify and repair connected drives using Disk Utility. So, choose that option, select your internal drive, and 1) do a Verify and Repair Disk at the Volume (ie, top) level, and 2) do a Verify and Repair Permissions, and a Verify and Repair Disk, at the Partition (ie, second) level. For #2, you would need to do that for each "visible" partition that you have.

Whether that works or not, you might want to consider installing an SSD inside your machine. As it is, I suspect the drive inside your machine now spins at 5400 rpm, which is rather slow. And, if the drive is going bad and/or you are using most of the space on that drive, it will be slower still. An SSD will make a world of difference!