Don’t now if this will help, as I have only worked on the force fx, dosage errors 16X I have found have been caused by breast surgery, the surgeons driving the excessively, causing the to over heat, but the have found if the switch off the unit and back on it clears the error and they carry on using it until it eventually fails. If you have replaced the fets, be careful and check there is no excessive ringing on the rf output stage when activated (I think it’s the drain of the FET TP19) this should be done once the fet is replaced at low power, if done at high power you will blow the FET again. If there is ringing the output transformers and the capacitors should be replaced. Note this is based on the force fx I don’t know how comparable they are.