[Riso RZ 970] Loud banging noise with one drum

[thibaut]

hey guys,
after dealing with clamp and master ejection issues, and replaced some parts on my RZ last months everything used to work. Just some master jams sometimes, stuck on the drums.

After a big crash yesterday (the machine shut down at the end of the process during making a master and putting it on the drum), the drum that was inside (my 2 other ones are working fine) have big issues.
It was stuck inside but I was able to manage the adjustments of position B to put it OK again to be released (and then inspect and try the other drums).

SO, since this crash, with this drum, every time I made a print (or just made the drum turning with a TM mode), it makes a loud banging noise in the master-making/suction unit area, each time approximately when the clamp passes the suction unit (it does not touch pressure roller, or the separator, of the parts where the master roll comes out).
It even can print so some timings are OK, but there is this big noise like the clamp noise or a plastic part smacked loudly, every time the drum turns.

All that I have discovered is that the TM804 clamp sensor B is always checked off. //[EDIT] I have check in my tech manual that is OK : when clamp unit is at home position, sensor B should not be detected//
And sometimes I have big error statuts like T01-521 (dealing with he position B sensor). I guess there is something to do with the timing but, since I moved a little the position B and A and they seem right, I don’t have a clue about this « clac » noise. Any ideas? Thanks!

[LAST EDIT] I solved the problem
As I had previously clamp issues with the machine : master jam, all the time. Even with brand new ejection plates. I modified the ejection plates of my drums (making them thicker) with little pieces of tapes. It works OK on all my drums but I surely have an issue somewhere with my ejection process.
Anyway this problem is linked to the original problem with ejection process.
The ejection plate was totally bend, I haven’t seen it before. I just saw it one hour ago, putting aside an OK drum (blue) and the crashed drum (Gold). Take a look at the pictures, it’s a big gap, I don’t know HOW it came to that, but I assume something was bad since the beginning and eventually scratched the inside of the machine, causing the big crash, and then the errors and the noises.
IMG_0932.jpg the Okay one
IMG_0936.jpg the bending ejection plate