The Desire S is a great phone so why did I want to root it?
The main reasons for rooting and s-off for me were:
Titanium backup (android built in backup is weak)
Being able to remove bloatware that takes up unnecessary spaces and unnecessarily reduces battery performance.
To try different ROMs from the community
Video screen capture
And of course I bought the phone so isn't it mine to use as I please.
Having waited a long time for a good s-off tool to come out I was getting more and more anxious to s-off.
Alpharev got together with Unrevoked to create Revolutionary.
I had previously used the Unrevoked tool to root my first generation Desire. The tool worked easily and flawlessly even on my Mac.
I later used the Alpharev bootable CD to s-off and root a later generation Desire. Again it worked smoothly and flawlessly.
Having had this positive experience I felt confident in the new tool, Revolutionary.
I read everything I could find about how the tool worked and how others were finding results. All seemed straight forward and uncomplicated so I proceeded to download and run the tool from my PC because there was no Mac version available.
Temp root and s-off went smoothly. No apparent issuse. Both Hboot and Fastboot had been successfully replaced on the phone, and CWM recovery was working.
So I added su in recovery then ran a nand backup of the whole system at this point.
Then I downloaded a Cyan 7 ported for the Desire S that was getting good reviews and feedback. The rom seemed to flash clean. After running it for a short time it stated crashing, so I decided to try an MIUI ported to Desire S. Again a ROM with good feedback and labeled as stable.
Downloaded the ROM and flashed it after a full wipe in recovery.
This time on reboot the phone hung at the HTC screen on boot for a very long time. So I wanted to do a force shutdown.
Here is where things got ugly.
The Desire S does not have a force shutdown keystroke combo as my old Desire did. So I opted to pull the battery.
Reinserting the battery and booting into recovery nothing worked properly.
CWM wouldn't mount its partitions, wouldn't flash a rom or even do a factory reset.
I tried doing some functions in fastboot mode. But nothing worked. Any command issued in fastboot mode would just lock up the phone and terminal.
At this point I was pretty worried so I got on #revolutionary and chatted with some of the big guns. I got some good feedback to test this and try that but in the end nothing worked. So I got on XDA forum and looked for others with similar issues.
What I found at this point was very troubling.
XDA user opumps had the same issue as me and had done some great research about the problem.
It becomes clear on reading, that like him, my Desire S had a fried eMMC chip. This is the internal storage device for HBoot. Once cooked your are basically F*ucked. There is no recovering from this by reformatting the eMMC. Pooched.
Doing the tests on the XDA post I found my eMMC to be pooched.
Now the question is, What fried the eMMc? Was it the S=off process or the forced pulling of the battery while the phone was boot locked?
I then took the phone to HTCs warranty center.
They tested the phone and called me back a few hours later. Your eMMC chip is fried they said. Yes, I said, Can you fix it please?
He told me that the eMMc was fried by the s-off tool I had used. Now, maybe he is full of **** and just wants an excuse to void my warranty. And, maybe not.
I told him to go ahead and fix it. He told me it would be a $200 Dollar replacement of the main board. ****. Well, what other choice do I have. Do it, I told him.
Next I got on the phone with the HTC help center. I got friendly with the lady technician on the call. After some nice chat I started probing for information on the Desire S. After a long conversation She told me that the Desire S, Incredible S, Desire HD all have the problem of frying the eMMC chip if the battery is disconnected while power is on. She said she gets calls every day with people who have fried their eMMC chip. Not through S-off but just because the battery came loose and lost contact while the phone was on or charging. The main reasons for the issue are as follows, HTC cheaped out on the eMMC chips in these phones, as the issue is specific to a particular series of eMMc. And because of a design flaw in the way the battery door closes, and because HTC did not include a force shutdown key combination to shut the phone off properly when locked.
So in the end it sounds like a lot of bad design and bad planning and poor foresight on HTC's part led to the fried eMMC on my phone. But they are not willing to stand behind their product and found an excuse to void my warranty and make me pay for the replacement Mainboard.
Now, here is where we get into the debate of should anyone s-off their phone? The main point here is no one should have to s-off. The phones should never be shipped s-on. It's bad policy to lock the bootloader. But having received an s-on phone you may very well want to s-off. If you decide to s-off just remember that you could easily brick your phone by many ways not related to s-off and your warranty will be void.
Another option is to not buy HTC because of the design flaws and their bad locked bootloader policy. To unlock and root a Samsung all you have to do is issue the command fastboot oem unlock. I don't know if Samsung phones also have the eMMc chip issue, so I can't comment there. But I certainly prefer their open policy on bootloaders.
Maybe the whole reason for locked bootloaders from HTC is beacause they are aware that they used sub par eMMc chips and are trying to reduce bricks.
Regardless this experience has made me very dubious of HTC in general.
I hope this is helpful and educational.