ok i shutted down the ds1z fw minutes ago. turned back on, now it can trigger at ~0.3V correctly. pressing the trigger menu, NoiseReject turned out to be at OFF state (remember this is after reboot). when i turn ON NoiseReject, it goes back to the OP problem, trigger only at > 0.6V weird, maybe some unseen noise going on? i have computer turned ON next to it.. trigger gets better at NoiseReject OFF.. but earlier when posting the capture above, i havent touch NoiseReject menu, so its weird... maybe the earlier boot, the NoiseReject is at ON position by some luck... and now the second reboot, the NoiseReject is at OFF, also by some luck, i dont know what was going on...