All three bleeds - check the reports in the link.
- I have just revisited the Greek accident report and there is a puzzle. The report states that the APU bleed was off, but the picture at page 50 clearly shows the APU bleed switch at 'ON' while the text says
"The left engine bleed toggle switch (BLEED 1) was found in the OFF position. The right engine bleed toggle switch (BLEED 2) was visually found in the OFF position. The APU toggle switch was found in the OFF Position. The isolation valve toggle switch was found in the AUTO Position. The left air conditioning pack switch appeared to be in the AUTO position. The position of the right pack switch could not be determined because of impact damage. The air conditioning panel was packaged and shipped to the Boeing Company, along with other systems components, for additional examinations (See section 1.16 for additional information)."
Edited to note: The report also confirms (I think!) that the Outflow Valve WAS in manual at impact based on the bulb filaments.