text: <s>[INST] PowerFlex 400 - no output Hello. I need your help. We have 8 PowerFlex 400 VFDs and one of them, from time to time, when we turn it on, it shows Hz on the output but I have no voltage or amperage on the output (it shows 0.3A on the output) .I checked the circuit to the electric motor and the input and output signals. Everything seems fine. The strange thing is that after a period when it is not supplied with electricity, it recovers by itself. I want to find out what the problem is and buy spare parts. [/INST] Hi Serbu, You are very Welcome. Please check and make sure that drive is running. The PowerFlex 400 drive does have a Run command per the Advanced Display parameter d302 [Contrl In Status] and or the drives' display shows an R in the lower left corner (R is for Run). Also check that the drive programmed b002 [Command Speed] and b001 [Output Frequency] match each other. Check Parameter b004 [Output Voltage] shows the logical Output Voltage the drive should have at its Output terminals U/T1, V/T2, W/T3. Parameter b003 [Output Current] equals something like 0.0 or 0.1 Amps. Parameter b005 [DC Bus Voltage] may equal the logical DC Bus Voltage. On PowerFlex 400 based on frame sizes there is an internal DC Bus fuse that maybe open. Or on any frame size it could be the circuit board that gates on the Output devices (IGBTs) have failed. In either case the drive is not field repairable. The drive can be sent in for repair. \\n </s>