[EVO 4G Q&A, Help & Troubleshooting] ProcessorHog:
Same here. My replacement phone works great, no reboots in six days and I tried hard to make it reboot. My replacement phone also has tons of light leakage at the bottom and the sides, but I'll absolutely take this over random reboots.

I took my old phone in to the store, with a few printed bug report pages with the "dsp dead?" or "dsp is probably dead" messages. They took a look at it and within 5 minutes came back and said that the phone had a hardware fault and they'll order me a replacement one. I don't have TEP/insurance, and I didn't have to pay a dime for the replacement. They said the phone was obviously faulty. My old phone was immaculately maintained as well.

Interestingly my replacement's hardware version says 0004 but I have a Nova panel with 3 point multitouch. I thought they didn't have Nova panels in newer phones... My old June 2010 Evo was HW0003, Nova screen and had 5 point multitouch. I don't use more than 2 and can't really think of a reason/app that needs more than 3, so am fine with it. Not having the damn thing reboot when I try to make or answer a call is worth the light leakage and loss of 2 touch points.

I think my phone is a refurb, but it looks new. No scratches anywhere, even on the stand. I wonder if it was a refurb on which they put an older model screen on...

Troubleshooting tips:

The following is what I did to troubleshoot my phone, and I was pretty confident it was hardware from what I saw. Thought this may help someone.

You don't need to have the phone rooted to pull a bug report off the phone.

1. Assuming you have the android sdk set up properly and can run adb commands, immediately after your phone reboots (within a reasonable time, say half an hour), connect it to the computer (make sure usb debugging is on in settings->applications->development). For learning how to use the sdk, read some of the other tutorials here.

2. Go to the directory with adb, then type: adb bugreport > ./bugreport.txt

The phone will vibrate at the start and at the end of this process. It may take a few seconds for this to complete.

3. Open the file bugreport.txt that was just created. Try to find a line that says "Do HW_RESET by APP not by RADIO". This would most likely be the last line of a specific section in the file.

4. Scroll up a bit and look around for anything that indicates a problem. For me, one reboot contained:

[45935.037658] Kernel panic - not syncing: Fatal exception

[45935.037841] Rebooting in 5 seconds..

[45940.020965] Restarting Linux version 2.6.32.27-netarchy-toastmod-4.3.2-bfs-nosbc-havs-more (natas@linphetamine-vm) (gcc version 4.4.1 (Sourcery G++ Lite 2010q1-202) ) #7 PREEMPT Sun Jan 23 12:33:40 CST 2011

[45940.020996]

[45940.021697] BUG: scheduling while atomic: Playback Thread/125/0x00000002

Kernel panics are NOT good. You'll also see a lot of byte codes and hex dumps, most likely register dumps. I don't know much about those.

Further up, I also had:

[45934.945678] audio_ioctl: timeout. dsp dead?

[45934.945800] Unable to handle kernel NULL pointer dereference at virtual address 00000000

[45934.946014] pgd = db3a0000

[45934.946105] [00000000] *pgd=3b377031, *pte=00000000, *ppte=00000000

[45934.946594] Internal error: Oops: 817 [#1] PREEMPT

From analyzing over 25 of these over a period of two months, there were only three that did not contain the "dsp dead" or "dsp is probably dead" message. I figured I may have a slow or malfunctioning chip that takes too long to respond, causing the kernel to crash and consequently reboot the phone.

If you can find a pattern (maybe it's some other chip that is malfunctioning on your phone), print it out and show it to them. If you do take printouts, MAKE SURE YOU UNROOT AND THEN PULL THE BUGREPORT because if you don't, your custom kernel version shows up in the report :) The bugreport also contains personal information (email addresses, things you did) so make sure you only take relevant portions of the report. Protect/delete the files once you're done because they have lots of internal info about your software, phone etc.

EDIT:

I also had a problem with 4G/Wimax not connecting on my replacement phone. Here's how I fixed it: http://xdaforums.com/showthread.php?t=1023735