[Galaxy A3, A5, A7, A8, A9 Q&A, Help & Troubleshoot] PJK2011:
I've spent all day fighting with the boot loop on my A500f.

I had the phone running really well with Ahmed's Resurrection Remix ROM on this post:

https://xdaforums.com/samsung-a-series/development/rom-resurrection-remix-5-8-2-sm-a500h-t3572062

He doesn't detail TWRP installation, so I used DeadSquirrel's 3.1.0 post here:

https://xdaforums.com/samsung-a-ser...overy-twrp-3-0-2-0-samsung-galaxy-a5-t3439233

I hadn't seen that TWRP can be installed without root, so I rooted with Chainfire first. I'm not sure, but I think I got the Chainfire file from this post:

https://xdaforums.com/samsung-a-series/general/how-to-root-galaxy-a5-a500fu-lollipop-5-t3137613

The file I downloaded for the A500f is "CF-Auto-Root-a5lte-a5ltexx-sma500f.zip" (contains tar.md5)

The post says it is for Lollipop, but the instructions say this is a Chainfire root zip for Android 4.4.4. One post suggested this might be the cause of my boot loop.

The instructions say that this Chainfire Auto Root solution also contains a recovery file, but I was never able to boot into this recovery, so I went directly to installing DeadSquirrel's TWRP. I was able to boot into this recovery. From there I installed the Resurrection Remix ROM. WIthin the ROM, I installed SuperSU from the Play Store, but SuperSU informed me the phone was not rooted, so I flashed the SuperSU root zip from their website, which I believe was the file, A500FXXS1CQC2_A500FOJV1CPH3_XFE.zip

SuperSU now reported root was present, so I installed WiFi Connection Manager from the Play Store, granted it root access in SuperSU, and used the Fix Problems menu item to repair the wifi shutting off the phone problem that I was originally working on. That fix worked well, so I left the wifi on and ran YouTube on Autoplay for about 4 hours. Deciding the problem was solved, I gave the phone back to my son, and he brought it back to me dead 5 minutes later. I'm not sure if it already that the boot loop problem at that point.

The phone would no longer boot. I noticed a seandroid enforcing notification, and thought it might be a security issue preventing boot. I found a thread that said I needed that flashing back to a Samsung ROM would remove the seandroid notice and that I needed to update to Android 6.0.1 before installing TWRP to solve the boot loop issue. I went to Sammobile and found the newest ROM for my A500f was the A500FXXS1CQC2_A500FOJV1CPH3_A500FXXU1CPH2_HOME.

I installed this in Odin, and the phone has never come back to me since then. I've made endless retries throughout the day, trying different combinations of the Chainfire root, different versions of TWRP, and different root methods, but all to no avail. One post even suggested that if you flash factory ROM from Odin just once, it will create a boot loop, but if you flash twice, it solves it, but it didn't work for me. It's also gotten increasingly difficult to get into recovery. Whether in stock ROM or TWRP, I was only able to get in about 10% of the time. Boot loop behavior has varied between boot logo - vibration - black screen and battery charge logo - vibration - black screen.

I found this thread that is supposed to address the boot loop problem, and I tried these versions of root and TWRP, but it didn't help:

https://xdaforums.com/samsung-a-series/development/recovery-samsung-galaxy-a52015-sm-a500f-t3360802

At the moment, I'm on stock ROM. On power up, you get the Galaxy A5 screen, then it vibrates and goes black, then the lightening battery logo comes up, it vibrates, and goes black, and then the green battery status logo comes up, and then the phone goes black. It's also booting into stock recovery okay, and I can do the recovery functions. I just can't boot the phone.

So now, I try the instructions again in ashyx's TWRP post. Now I can get into TWRP. I power up and the phone sticks on the Galaxy A5 boot screen for a long time. Then it vibrates and repeats. It's basically the same as above, but there is a long delay before rebooting instead of instantly as before. Now I go back into TWRP and flash the Resurrection Remix ROM and the behavior is the same. Power up and get the Galaxy A5 boot screen for 8 seconds (this time sporting a warranty bit: kernal notice), 2 seconds of black screen, vibration, battery/lightening logo blinks on, then off, vibration, battery/lightening logo blinks on then off. Black screen, then standard battery charging percent indicator. I did that three or four times to make note of the behavior. Then the power switch wouldn't work, so I used the technique to press the volume up and down key together with the power key to turn it back on. Now it is in a non-stop 5 second cycle of vibrate - flash the icon - black screen that won't quit. Throughout the day I've been stuck with this in both stock and custom ROM. Only once during the day did I see the custom ROM boot all the way through. The stock ROM has never booted.

Now the recovery key combination won't boot TWRP either. The key combination just makes the Galaxy A5 screen flash instead of the battery icon. But I can get into TWRP by rebooting with the recovery key combination on leaving Download mode.

If anyone understands what's wrong here, I'd appreciate it.

Thanks