i tried upgrading my ZTE W N61
Stop.
Did you have N61 of Bluebelt?
do you have all the drivers in your computer instaled? have you tried whit the 6.1 version from Alex and then try to install the 6.5 version?
Guys, I have important note for all of you.
ALWAYS USE ORIGINAL ROM (FROM TMN/ZTE) FOR RECOVERY. ALWAYS.
Because only original ROM have complete set of files - bootloader, radio, scripts and so on. Also it prevents many questions and doubts.
In case of "3-5%-FAIL" problem, as I already sad, phone can't start flashing procedure after loading and launch flash script. Why it happened - I do not know. Log of flashing we can see only by using QPST software from Qualcomm, but you should know - this software can kill your phone.
BTW, one of my Silverbelts dead same way - sometimes flashing hangs at 29% (when flasher try to flash main firmware). But sometimes flashing pass 29% and completed ok. In one fine day hangs becomes permanent. And after few days phone dies completely (bricked). I'm sure - NAND flash of this Silverbelt was produced with defects and flash chip slowly degraded, then completely fails. NAND flash (ROM) of Silverbelt/Bluebelt produced in one chip with RAM and have few regions. When main flash region of my flash fails, I could not read/write main firmware, but could read/write radio and bootloaders. When all regions fails, I got the brick.
So. What you can do now?
Now and then - remove battery, SIM and SD from your phone and try to flash without them.
If your phone is bluebelt:
1. Try to flash only radio firmware (from bb1/bb2 - not matter).
2. Try to flash your phone with original Bluebelt firmware.
3. Try to flash your phone with original Bluebelt
II firmware (read instruction for this firmware first). Remember - your phone may become bricked. After flashing BB2 firmware try to flash BB1 firmware again.
4. Use QPST. But now I can't say more about it...
If your phone is n61:
All the same - n61 can be flashed by TMN ROM:
http://xdaforums.com/showthread.php?t=953566
Good luck.
BTW. My Bluebelt somtimes hangs when flashing on 28-99% (maybe because it water-damaged, maybe because of low PC system resources). That's why I removed radio and bootloader from custom rom flashers - radio and boot areas stays intact when flashing...