Can someone give me some advice. I have been building systems and watercooling for years and have never had any major problems. This weeks I bought three EK Waterblocks for my three GTX 280 cards, which I have been running on air in tri-sli. I fitted the blocks (carefully I thought) and put them back in my loop. I always run the loop first to ensure no leaks then attach the cards to the motherboard. After a day of leak testing I was horrified to find only one of the three cards was working. I have now tested each card individually and confirmed that only one is working, the system will not even boot with the other two!! Before I buy two more cards does anyone have any ideas or hints as to what I did wrong. BTW I have now ordered three EK Alu backplates from EK.