Power led flashing

Spartan-3 USB 2.0 Modules
1

hi,

the power led of my 3010 is flickering. the 1.2 V output seems fine, but the 3.3 V output is oscillating at about 18 Hz with a duty cycle of 30% between 0 and 3.3 V. it looks like the 3.3 V regulator is gone. any recommendations for replacing or figuring out if that is indeed the case or if the rest of the board is also damaged?

thanks,
regards,
kartik

2

@kartik-

This is a symptom of a blown regulator (U1 is the Maxim MAX1831EEE+ that handles 3.3v).

The most frequent cause of this is over-voltage (someone attaches 12v to the device which has a voltage input range of +4.5v to +5.5v). It can also happen with an over-current situation (power/ground short).

In most cases, replacement of U1 (for +3.3v) fixes the situation. Depending on the case, however, other devices may have been damaged.

3

hi,

thanks. that sucks.

is it possible to desolder the chip and connect a separate 3.3 V supply to the 3.3 V pin in order to confirm if the rest of the board is functional? if functional, i’ll go ahead and solder in a new regulator in place of the old one.

thanks,
kartik