External display stops working since 10.10.3

[RehabMan]

I have exactly the same issue. I have rebuilt the cache for several times, no luck.
8470P, HD4000, 1600x900, DP to HDMI coverter.

Read post #9.

 

[bulkonly]

Thanks for the help. It is working now.

I did the file comparing of config.plist, versions before and after 10.10.3 upgrading, found one Kext2ToPatch item was missing:

Old version has:
Patch HDMI-DP port HD4000 1600x900 #1
Patch HDMI-DP port HD4000 1600x900 #2

New version only has:
Patch HDMI-DP port HD4000 1600x900 #2

(i re-installed the 'ProBook Installer' after 10.10.3 upgraded, which might be the reason of config.plist modified).

I modify the new version config.plist, added the missing item, reboot, the external display is working now.

 

[nguyenmac]

Thanks for the help. It is working now.

I did the file comparing of config.plist, versions before and after 10.10.3 upgrading, found one Kext2ToPatch item was missing:

Old version has:
Patch HDMI-DP port HD4000 1600x900 #1
Patch HDMI-DP port HD4000 1600x900 #2

New version only has:
Patch HDMI-DP port HD4000 1600x900 #2

(i re-installed the 'ProBook Installer' after 10.10.3 upgraded, which might be the reason of config.plist modified).

I modify the new version config.plist, added the missing item, reboot, the external display is working now.

Thank you for pointing this out, actually I tested something regarding memory in my own config.plist, and forgot to put the #1 back.

I can't understand why your #1 is lost. Can you check the latest PBI CE again? I didn't modify the patch for HD4000 at all.

 

[bulkonly]

...
I can't understand why your #1 is lost. Can you check the latest PBI CE again? I didn't modify the patch for HD4000 at all.

PBI CE Version 6.2.15.5 (April 9th 2015)
I didn't make note to record what i did. But i remember after installed the 6.2.15.5, I noticed both #1 and #2 are there, then, I did some test in PBI, so it might be me who delete the 1#. (Sorry i am not 100% sure)

 

[bulkonly]

Now I found a new problem:
it cannot set the resolution for external display (connected via DP->HDMI converter).
Before the 10.10.3 upgrade, it can be set.

 

[RehabMan]

Now I found a new problem:
it cannot set the resolution for external display (connected via DP->HDMI converter).
Before the 10.10.3 upgrade, it can be set.

SysPrefs->Displays.

 

[bulkonly]

SysPrefs->Displays.

Thanks Bro.
It gives me 2 options:
1600x900
1344x756

However, the external display's physical resolution is 1920x1080, before the 10.10.3 upgrading, it works in 1920x1080.

 

[RehabMan]

Thanks Bro.
It gives me 2 options:
1600x900
1344x756

However, the external display's physical resolution is 1920x1080, before the 10.10.3 upgrading, it works in 1920x1080.

Are you mirroring or extending?

 

[bulkonly]

Are you mirroring or extending?

It is extending (Not check 'Mirror Displays')

 

[RehabMan]

It is extending (Not check 'Mirror Displays')

Press option when you select "Scaled".