text: <s>[INST] 2094-BM01-S Fault with no Fault Code Summary: Mystery FaultYesterday evening one of the 2094-BM01-S servo drives on a piece of equipment showed a Red Light at the Drive Status light. Looking up in the manual shows that as a drive fault and to read the fault code. The drive does not show a fault code and all the servos on the bus bar are at boot step 3. When I cycle the power the light turns off until at step 3 again then lights back up and stays at step 3. PLC software shows the drive faulted, but resetting the fault does not do anything and will not indicate what fault it is. A new drive was ordered and installed but problem continued on new drive as well. Unplugging all cables does not clear the fault nor does unplugging all the cables on the servo drives next to faulted drive mirror the issue. I am at a loss, any help or direction would be appreciated. [/INST] Logix/Studio 5000 should show some sort of error code for the drive on its properties dialog box. Check out these knowledgebase articles. Most talk about a firmware / software problem with one specific combination and a phase loss attribute new to that version - did something in the system get upgraded? The other possibility is that something happened with the encoder in the motor or with the motor definition in the PLC program such that it doesn't match the actual motor. Was someone in the program recently? https://rockwellautomation.custhelp.com/app/answers/detail/a_id/48500 https://rockwellautomation.custhelp.com/app/answers/detail/a_id/48895 https://rockwellautomation.custhelp.com/app/answers/detail/a_id/33524 https://rockwellautomation.custhelp.com/app/answers/detail/a_id/56938 https://rockwellautomation.custhelp.com/app/answers/detail/a_id/23802 https://rockwellautomation.custhelp.com/app/answers/detail/a_id/53546 \\n </s>