Board doesn't boot with debug console connected.

[toxatoor]

Hi,
Got a weird behavior with my R4S board. The board itself boots with no issues from SD. Now, I need to get u-boot console there. Hooked up my usb-serial to the board, powered the board up - and nothing happens, the board doesn't boot at all.
Investigation show, however, that if I disconnect RX pin from the board - it boot, showing proper bootlog etc. If I connect the RX pin after the board goes live - everything works like a charm.
But I'd like to have console hooked up from the very beginning.

So what might be the reason, and how to solve that? usb-serial leveled at 3.3V, the chip is FT232. Any ideas?

Thanks.

[toxatoor]

Upd: Doesn't matter, changed breakout board to a cheaper one with the same FTDI chip - works like a charm.