In effort to resolve flakey behavior of multiple TRB245 we are using, I have tried entering the bootloader using power up with reset held in but cannot get TRB245 to enter bootloader mode. There appears to be several versions of instructions for entering bootloader mode, one says hold reset for 3-4 seconds and another says hold reset for 4-8 seconds but neither work for me. Unit is batch 044. Please advise correct process for entering bootloader.