GE Healthcare · X-ray R&F

MVP3 Error 40 Voltage at Main Thyristor During Exposure

Symptom

MVP3 Error 40 Voltage at Main Thyristor during exposure. This error means that there is voltage at the Forced Commutation Main Thyristor during exposure, which is the equivalent of saying there is no exposure. This check is carried out from the time CLOSED LOOP signal is activated until the end of exposure. This error is considered FATAL for the system.

Error message

MVP3 Error 40 Voltage at Main Thyristor During Exposure See long description. The equipment should be switched off and when next switched on, in order to reproduce it again, another exposure should be initiated. Check whether any one of the thyristor control board LEDS corresponding to precontactor excitation is illuminated. Also check the precontactor current detection LED. If it is repeated, you should investigate the cause of the non-variation in level at pin P14 of the Forced Commutation Microprocessor U282. ONLINE CENTER COMMENTS AND TROUBLESHOOTING TIPS 1. On the Firing Board, observe LED DS175 (GMAIN) which indicates if the Main SCR Q2 is being turned on. 2. The Main SCR Q2 may be turning on, but has become resistive. There may still be voltage across it is turned on. 3. Replace the Main SCR Q2. Order as an assembly. The Main SCR has a press pak device. The correct pressure between the assembly plates is critical. If for any reason the FE has elected to order just the SCR and is reassembling the press pak, the correct torque on the two screws that hold the press pak together is reached when the tab in the center of the assembly is just free to move.

Applies to

Product
MVP 3 Phase
Area
X-ray R&F

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