Black screen AGAIN after 10.10.4 update, please help!

[171621]

AMD Radeon 7850M, successfully updated to 10.10.3 using fix method: modifying info.plist of AMDRadeonX4000.kext, changed AMDVerdeGraphicsAccelerator as:

                <key>CAIL_DisableDrmdmaPowerGating</key>
                <integer>1</integer>
                <key>CAIL_DisableDynamicGfxMGPowerGating</key>
                <integer>1</integer>
                <key>CAIL_DisableGfxCGPowerGating</key>
                <integer>1</integer>
                <key>CAIL_DisableGmcPowerGating</key>
                <integer>1</integer>
                <key>CAIL_DisableStaticGfxMGPowerGating</key>
                <integer>1</integer>
                <key>CAIL_DisableUVDPowerGating</key>
                <integer>0</integer>
                <key>CAIL_DisableVCEPowerGating</key>
                <integer>1</integer>

Combo updated to 10.10.4, the screen went black again after loading kexts, tried fixing with the above method but didn't work, now it went black even I enabled the Safe Mode~~~~

Here is my notebook info:

HP Envy 17t-3200 CTO 3D
Board：HP 1852 (Intel Ivy Bridge - HM76 Express)
CPU：3rd Gen Core i7-3820QM @ 2.70 GHz Quadcore
Graphic Card：ATI Radeon HD 7850M/8850M
Sound Card：High Definition Audio Device @
Ethernet Card：Attansic AR8151 V2.0 Gigabit Ethernet Controller
Wireless Card：Intel® Centrino® Ultimate-N 6300 AGN
DVD ROM：HP BD E DC6E2SH Blu-Ray Combo
Bluetooth：Broadcom 20702 Bluetooth 4.0
External Keyboard：Logitech MK330 USB 3.0

It seems that BIOS has blocked the Intel HD Graphics on my notebook. Also I am using chameleon booting method with extracted graphic rom file and the following SMBios.plist settings:
 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
                <key>SMbiosdate</key>
                <string>04/22/11</string>
                <key>SMbiosvendor</key>
                <string>Apple Inc.</string>
                <key>SMbiosversion</key>
                <string>MBP81.88Z.0047.B04.1102071707</string>
                <key>SMboardproduct</key>
                <string>Mac-94245B3640C91C81</string>
                <key>SMfamily</key>
                <string>MacBook Pro</string>
                <key>SMmanufacter</key>
                <string>Apple Inc.</string>
                <key>SMmanufacturer</key>
                <string>Apple Inc.</string>
                <key>SMproductname</key>
                <string>MacBookPro8,1</string>
                <key>SMserial</key>
                <string>C02F9DHNDH2G</string>
                <key>SMsystemversion</key>
                <string>1.0</string>
</dict>
</plist>

Seeking for help~~~ Many thanks in advance!

[hooda]

i think u need to move all gfx kext in /S/L/E to another place first, and then try to reboot again. maybe it helps just for boot in to your osx desktop.

[Slice]

I think you have to remove the link to tonymac else ban. See forum rules.

 

Really your problem comes from that site.

[171621]

I think you have to remove the link to tonymac else ban. See forum rules.

 

Really your problem comes from that site.

 

The link has been removed, also I found the solution. Thanks for reminding~~~~~

OK, so no one can answer my question, then I'll do it myself: found a temp solution, which is replacing the 10.10.4's Framebuffer file in MacOS folder of AMDFramebuffer.kext with 10.10.3's Framebuffer, then install the modified AMDFramebuffer.kext back to S\L\E, clear caches and fix permissions. reboot and enjoy~~~~