I plugged the iPod cable coming from my 7-year-old Pioneer car stereo (9400MP) into my iPhone 2G last week as I do daily. This time, however, there was some funky black and white lines on the display of the phone. I unplugged it, rebooted the phone, and things seemed okay.
A few hours later, when I was charging it, I noticed that it got warmer than normal. Then the phone began acting strangely. The next morning, the charging warmth seemingly diminished so I decided to restore the firmware to see if the software oddities - and a few random reboots over the night - could be fixed.
QuickPwn didn't work - I believe the errors that I got were (1601) and (1). I tried Pwnage Tool but that didn't work either. In fact, when I put the phone into DFU, that was the last thing that it ever displayed.
I don't *think* that it's stuck in DFU. I have tried a couple of times each day for the past week to turn the phone on -- even holding both buttons for up to 5 minutes at a time. I've plugged it into Windows PCs and just the AC charger. Nothing.
The odd thing is that if I plug it into the dock on my Mac, the phone stays blank, but eventually - several minutes later - iTunes pops up with a message that it has detected an iPod. If I click CHECK to identify it, I get the error (1621). But that's the only sign of life I get. No warmth when attempting to charge. No noise. Nothing on the screen at all.