cyril7: Sky boxs ( and FreeView/FTA ones for that matter) only really turn off if you remove the power, putting them in standby via the remote only stops the video/audio output and the status leds on the front panel, the power to the LNB continues. Trap for young players. You need to pull the Karapiro totally.
cyril7: 50meters of coax and a splitter is still well inside the reasonable allowance, you are only 32meters, you dont need an amplifier, infact an amplifier without a large loss to compensate for can overload STB's, purhaps this is what has happend on some transponders.
Without suitable test kit you cannot test the amp outside of simple substution.
I suggest you forget the amp its not needed in your setup. On you Sky box what signal level and BER does it report. Is it a Pace or Motorola/Zenith, the latter have quite accurate signal level readings.
cyril7: Those signal and BER levels are perfectly fine. The BER (which is directly related to Carrier/Noise) is the important one and what you have is pretty much as good as it gets. Being a Motorola the level should be pretty accurate and you say 70 which is 70dBuV. The acceptance range of most DVB-S recievers is typically 40-80dBuV hence the colour bands on the scale indicate this in green. So 70dBuV is a good signal. I have seen these receivers happily work down at 25dBuV, so long as the C/N (quality and BER) at the dish are adequate the signal can fall due to line losses and as long as the result C/N is not compromised by the reciever noise floor they work just fine. You are light years away from that.
I assume the cable lengths from the splitter to each STB is similar so the Hills is seeing a similar level and C/N signal.