The investigation was carried out on the basis of the photos sent and the gcx hinged arm provided.It could be determined that the affected unit and the returned gcx arm are already approx.16 years old.According to the photos sent in, the affected swivel joint is the front swivel joint with vesa monitor mount.The screws for attaching the keyboard holder are located on the underside of this swivel.The keyboard holder was mounted with 3 hand-tightened screws.Some of the screw heads showed considerable damage, indicating repeated overstressing, possibly with the use of unsuitable tools.After disassembling the keyboard holder, the pivot bearing was checked.In the process, wear of the individual components could be determined.Some of the teflon discs were severely damaged, so that low-friction rotation of the joint was no longer possible.Accordingly, a significant amount of metallic abrasion was also found on all parts.The screw for tensioning the pivot bearing also showed considerable damage to the thread, indicating improper assembly/repair.Overall, the affected arm shows clear signs of wear.The screws marked on the photo sent serve solely to fasten the keyboard holder, so that loosening this fastening cannot lead to the monitor attached to the vesa mount falling down.This is only conceivable if the clamping screw in the joint loosens and turns out so far that the forces introduced can no longer be absorbed.Since the screw can only loosen when the joint is turned, it can be assumed that a loose swivel joint will be noticed promptly by the user.The hinged arm used has been designed with fourfold load safety in accordance with the iec standards applicable at the time of placing on the market.This means that it is highly unlikely that the arm or the attachment will break when used as intended within the permissible load limits.Finally, it can be summarised that the loosening in the screw connections as well as in the swivel joint was favoured by the wear of the components of the hinged arm.In addition, indications of improper repairs and unrepaired damage, especially to the connecting elements, were found.As a result, there is the possibility of subsequent faults which, among other things, could lead to the hinged arm falling down.It is not possible to determine who carried out the improper repair and who caused the damage.So far, no other comparable cases have been reported to us.The gcx arm has already been replaced at the customer's site.
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