The faults found in the sales of tubes and CT maintenance mainly fall into two categories: one is the fault caused by misoperation, which is the most common type. When the machine is not functioning properly, the first thing to consider is whether there is a misoperation to avoid taking detours. The second category is genuine hardware malfunctions. When hardware is damaged, there are often fault reports. Based on the analysis of the situation, accurately identify the location.

I. CT Machine malfunctions Caused by misoperation:

CT malfunction phenomenon one: The CT machine fails to work, the scanning frame does not rotate, and the problem persists after several attempts to turn it on and off.

According to the indicator light on the scanning frame, it was indicated that the CT machine had been urgently shut down. Later, it was found that this false fault was caused by accidentally pressing the emergency switch beside the bed. After pressing the emergency stop switch beside the bed and the reset key on the control console keyboard, the CT machine resumed normal operation.

Problem analysis: The emergency stop switch beside the bed is prone to misoperation. When the CT machine is not working, it is necessary to first check whether the emergency stop switch can be pressed.

CT malfunction phenomenon Two The CT machine failed to take photos. When pressing PRINT in the FILMCOMPOSER window, an error was reported. It was found that the DICOM display at the top of the FILMCOMPOSER window changed to LASER CAMERA. Click LASER CAMERA. This line of text can be selected as LASTERCAMERA or DICOM. If you still can't take photos after selecting DICOM, just SHUT DOWN the APPLICATION, reset the CAMERA parameter in the RECONFIG, restart, and then delete the sorted photos in NETWORK and FILMING in the QUEUE menu of the BROWSER. At this point, the CT machine takes photos normally.

Problem analysis: The possible cause is that during the photo operation process, doctors can easily click on DICOM with the mouse and change it to LASTER CAMERA. Even after changing it back to DICOM, the DICOM parameter will be lost. This is a BUG in the program, but this BUG can be fully resolved after the program is upgraded to 6.0.

CT malfunction phenomenon three: The scanned images are very poor.

At first, I suspected it might be a problem with the tube and prepared to make corrections. However, based on the observation, the CT only had poor images when scanning the head with one protocol. After checking the parameter Settings, I found that this protocol used BONT reconstruction instead of STAND+. After the correction, when scanning again, the CT machine's images returned to normal.

Problem analysis: It might be that the operator mistakenly changed this parameter.

Ii. Hardware Faults of CT Machines for Tube Sales:

CT machine malfunction 1: The RAWDATA hard disk is damaged.

The fault phenomenon of the tube sales: When the CT machine is turned on, the system self-check reports HINV and NPR errors. After reinstalling the system, it works normally, but the same fault phenomenon occurs again a month later. Sometimes, it also reports RAWDATA DISK errors, and the fault occurs more and more frequently. It is always necessary to reinstall the system to solve the problem.

Fault Analysis and Repair Suspecting that there was poor contact or a soft component problem in some parts of NPR, I replaced the five circuit boards of NPR with the same model of CT machine to test. However, no obvious problem was found in any of the circuit boards. As long as they were reinstalled and the problem phenomenon was carefully analyzed, the problem was always solved by reinstalling the system. Could it be that there was a problem with the software or that there were bad sectors on the hard disk, but it was impossible to determine. Later, it was found that sometimes even reinstalling the system couldn't solve the problem. One had to format the hard drive and then reinstall it. Sometimes, the RAWDATA DISK error was reported upon startup. After replacing the RAWDATA hard disk, the CT machine's malfunction has never occurred again.

CT machine malfunction 2: The SGI mainboard is damaged.

Fault phenomenon: The CT machine starts up with a black screen. After a while, the display shows "NO SIGNAL", and no sound of the OC relay closing is heard.

Fault Analysis and Repair It is obvious that the entire computer has not started up in part. After ruling out the problem with the display, the focus is on looking for the SGI. Since the SGI is highly integrated, the entire system only has a few circuits, with the graphics card and network card integrated on the motherboard. Additionally, there is one CPU board and six memory sticks (very similar to a regular computer). First, measure whether the input power supply is normal. If the power supply is normal, then check. Then check if there is any poor contact between the CPU and the memory. Plug and unplug them again, and only insert two memory sticks. There is still no response when the computer is turned on. The CPU is generally not prone to failure. After replacing a few memory sticks for testing, the CT machine still had problems. It seems that not all the memory sticks are faulty. Therefore, I suspect that the SGI motherboard is damaged. I carefully examined the motherboard with a magnifying glass and found that there seemed to be a thin layer of solder mist between the hundreds of solder pins in the part of the memory slot closest to the motherboard chip, the contact area between the slot and the circuit board. I carefully cleared the tin mist, installed it and then turned it on again. The problem with the CT machine sold by the tube was eliminated, but I still don't understand why it didn't break down until two years after use? It is estimated that other PROSPEED model CT SGI motherboards may have similar issues. This is for reference only again.

Problem 3 of the CT machine for tube sales: Poor contact of the OGP board chip.

Fault phenomenon: When the CT machine is turned on and enters the desktop, it reports an OGP error, fails to WARMUP, and cannot scan.

Fault analysis and repair: Based on the fault prompts, locate the OGP part. Disassemble the scanning frame and manually operate on the TGP board to check the indicator lights. No abnormalities were found. Disassemble the OGP board and measure that the input power supply of the OGP board is normal. Press the chip on the OGP tightly, plug in the wires, and then turn on the machine. The CT machine returns to normal. It is estimated that the cause of the problem is poor contact of the CPU chip on the OGP.

CT machine malfunction Four: Malfunction of the uniform magnifying board.

Fault phenomenon: The CT machine starts up and enters the desktop, reports SERV AMP error, the scanning frame does not rotate, and sometimes it can handle patients but stops halfway through the scan.

Fault analysis and CT repair: Based on the fault phenomenon, the scanning frame was disassembled, and the uniform was taken apart to magnify the local area. Surprisingly, rat urine was found on the circuit board. The circuit board was removed, carefully cleaned with alcohol, and then dried with a hair dryer. After reinstallation, the CT machine was turned on and resumed normal operation.