Black screen and fans running high after 10.10.5 update?

Same here.. Actually, Machine will just boot to blank screen and sometimes shutdown for no reason at all. Need a fix ASAP.

I'm not seeing any issues on my Macbook Pro 13' Early 2015

Edit: I used the combo update and the Mac AppStore update.

For those of you experiencing the problem, what specific update did you apply? I mean Combo Update or the regular delta version? We always apply the Combo Update here. I've installed it (Combo version) on a small number of MacBook Airs and Pros and have not seen any issues.

+1 to what @mm2270 wrote...Combo Updater all the way.

Not seeing the issue on Mid 2015 MBPr (work) or Mid 2014 MBPr (personal).

do you have any firmware updates out standing at all? i had a similar issue earlier today but i found there was some firmware updates waiting after i applied them and it resolved the issue

It is the regular Mac App Store updater - we've seen 4 so far out of 218 who have updated. No outstanding firmware updates...

We can't repair them from Single user mode either, just when booted from an external disk.

I think Apple are delivering firmware these days with OS updates which is why you sometimes see a double-boot after and a black screen for longer than normal. I've not seen this issue on a number of Mac models, nor in seed testing.

Quite often you also need to check for mds processes running as that can make the fans go wild after an OS update...

Make sure you let the process(es) finish before interrupting with a reboot, etc.
One one that's acting up, I'd download and install the full installer to see what happens. And I agree with the Combo update thing - we always use those and have for years.

examine the /var/log/install.log from an affected system, for anomalies that may affect startup, Recovery HD Updates, firmware. Is it far enough you can use verbose to see what it's having trouble starting up? However if repairing the disk corrects the problem, were they file system or permissions issues?

Tested on 2014 MBPr 15", 2012 MBPr 13", and 5k iMac no issues... I didn't use the combo updater as well.

We've had a few folks on 2011 and 2012 MBPs have a problem after installing the 10.10.5 update where it reboots and it looks like it's dead but the backlight of the screen is turned off. NVRAM usually sorts it out.

There is definitely a firmware update being applied as part of the 10.10.5 Combo update - I see it installing in the install.log.

Sorry for the double post from another thread, but it looks like it could potentially be related to Macs with policy banners: https://support.apple.com/en-us/HT202277

We do have a policy banner in place in my org, so if this pops up for someone I'll see if the troubleshooting steps provided in the article linked above help.

@emilykausalik I can confirm that we're seeing this behavior as well. It started this week and we're seeing it with Macs updating to 10.10.4. The Policy Banner stops the final step of the upgrade when UserAccountUpdater tries to run. We're using FileVault so authentication happens at boot before the Policy Banner displays. Renaming /Library/Security/PolicyBanner.rtfd to something else via SSH stops it from loading and allows UserAccountUpdater to run. After it runs, we were able to reenable PolicyBanner.rtfd and everything works as expected.