Well this feels like a reunion of sorts. Glad to see you and Frank are doing well.
You inspired me to post after over a year... :-)
Have you restored yet or are you still having issues? I assume restored...
Hmm often that combined re-installing ultrasn0w works. since no one else is chiming in I would re-install ultrasn0w after the mobile substrate re-install and the do a "slide to power off" then turn it back on. Also if you had to turn "3G" off in the past to get a connection ensure that "3G" is disabled.
Have you re-installed mobile substrate?
Ah, sorry. My sons is old bootrom, and therefore always untethered, maybe that is why it comes back on. I will ask a few people that might know.
Do you recall the battery charge level? This happens to my sons 3GS everytime it crashes when the battery is critically low. After 5 minutes or slightly more on a direct charger it always comes back on.
Do you mean your entire screen turned Yellowish kind of like a crash?
As I understand it ESN number is "electronic serial number" which is the phones IMEI number on the iphone. If that is "bad" then I assume it is blacklisted and not functioning. Have you asked the seller to clarify this?
Also, and probably the main point, the iphone must be a GSM phone with the 01.59.00 baseband (modem firmware) for it to be unlocked. Asked the seller if it is GSM and what the baseband version is under "settings/general/about/Modem Firmware". Again, it must have the 01.59.00 baseband to be software unlockable.
Follow @musclenerd on twitter. He has a way to downgrade from 06.15.XX baseband back down to an unlockable version thereby giving you both an unlock and GPS. He is aiming for a Funday release but it may take a little longer. As Willy's said be sure you 3GS is older than the date he gave!
They never know if they are going to find an unlockable exploit and therefore do not and cannot give ETA's. By following @musclenerd I do not believe they currently have an unlockable expliot. All you can do is wait and hope, sell it, or do a search for Applenberry for a sim interposer.
Sounds as if you may also be in DFU mode but not Pwned DFU. I have seen in the past where my phone would be recognized as in DFU but I couldn't do anything with it. You can try a hard reset. Hold home and power, forever, until it reboots. As soon as you see the apple logo let off of the home button. Then use the latest redsn0w to try and enter Pwned DFU mode again.