First try an hard reset, this can be done with pushing the _commmenager-button+Camera-button+stylus-reset(on bottom of ur device)_ at the same time, just release the stylus-reset some earlyer then the other 2 buttons.
if thats not working:
Try to charge your mobile with your original charger,
Then go to your bootloader, put in the USB Cable.
goto the site of your brand of phone... imate / qtek or whatelse...
download official WM5 ROM.
try to flash it again.
Also flash your radio rom to 02.19.21
I like 02.19.21, i think its the best radio-rom for prophet i ever used.
but that can be because i have Vodafone, dont know if its also the same with your provider...
but i should say, give it an try!
here you can download all Radio-Roms.
First of all, when u start flashing again to WM5/6 (doesn't matter what rom) always use HARD-SPL!
And i can advice you an good rom(although for me in case)
The rom made by VaranusVincent
ROM Prophet Blue Manilla 2d
[WM6]/[WM6.1] Wifi Fix for missing WPA2 and AES Encryption!
Device: HTC Prophet
OS: [WM6] Mixed WIZZARD / Prophet rom! // WPA2-PSK AES Working with fix! by: Charevian
Device: HTC Touch Diamond
OS: Official Dutch WM6.1 Rom!