I had the same issue with the bootloop with PMP3870C_DUO. I found the solution on a russian forum 4pda.ru, post #32 from user ogsstudio.
Here are all tools needed for flashing, and here is my HowToInstall not perfectly translated...
Download ROM and TWRP from this post: http://forum.xda-developers.com/showthread.php?p=49903407
If you want to install SlimKat-BiG. xd-4.4.4-9.0-20150111.zip you need to change your One X to New Layout.
New layout changes the HOX to use all m...
Did you just throw that site together? lol......... Scam Scam Scam!!!!
Yes, I see it now, they even don't have S5 listed on that site :(
...but this one seems professional link .it's SeerePetrova's link
you can find there sprint s5 cdma, which is...
Please post the amount you like to pledge. here is the bounty thread..http://forum.xda-developers.com/sprint-galaxy-s5/general/sprint-sm-g900p-gsm-international-sim-t2832927
I have. Please add it to the total sum in the 1st post....