DC series

• Discharged BIOS (CMOS) battery on the motherboard
• If the battery is fine: a faulty board (I/O board or the main/CPU board)

1. Measure the BIOS battery voltage. In one case it read normal (3.20 V) and the fault turned out to be elsewhere.
2. Check the battery size before ordering. CR2032 was used in these cases; CR2025 was asked about for one model.
3. Measure the power supply output voltages at its output connectors
4. Check the main power supply by fitting it to a known-good system
5. Work through the troubleshooting section of the service manual

On a DC-3 with only a short beep, replacing the CR2032 BIOS battery fixed it (this needs the housing opened). On other units, replacing the battery and then setting the date and time was recommended as the likely fix. Where the battery tested good and the power supply was confirmed working, a faulty board was suspected, but no confirmed fix was reported.

• Failed I/O (interface) board. Field reports call this a common failure on DC-3 and DC-N6/T6.
• A failing DC-DC converter on the I/O interface board that cannot carry the load (monitor, control panel and disc drive share one supply)
• Short circuit in the control panel, or failed suppressors on the USB ports
• On one DC-40 (model uncertain), a motherboard fault: the keyboard answered only to probe selection

1. Check that the control panel gets power and that its backlight works
2. Plug a standard PC USB keyboard into the system to see whether input works at all
3. Confirm that the probes still work
4. Check the control panel for a short circuit and inspect the USB-port suppressors
5. Disconnect the disc drive's power and/or the battery, then restart, to see whether lowering the load changes the behaviour

Probable: replace or repair the I/O interface board (including its DC-DC section). On a DC-N6, disconnecting the disc drive got the system to start once, but the fault came back on the next start. For the DC-40 case with an unresponsive keyboard, replacing the motherboard was recommended. None of these repairs was confirmed in the field.

• Faulty DC-DC board, which sits above the AC-DC unit

1. Check the indicators on the DC-DC board above the AC-DC unit. Three indicators should be lit; if they are not, suspect the DC-DC board.

Probable: a fault on the DC-DC board. No confirmed repair was reported.

• A failing hard disk (logs showed the system restarting several times a day before the disk died completely)
• File system errors on the hard disk
• Corrupted application software
• The disk filling up because the temp folder has grown too large

1. Review the Windows logs for repeated restarts
2. Check free disk space and the size of the temp folder
3. On Linux-based systems (Resona / DC-X6), open the boot console (Alt+D, or Ctrl+Alt+F1/F2/F3) to see where the boot stops. If it asks for a file system check, answer 'y'.
4. Allow plenty of time for a slow boot before deciding the system is dead

On a DC-7, replacing the hard disk and reinstalling the OS and application fixed it. Access to the disk on the DC-7 needs the whole housing removed. On a DC-30, reinstalling the application software fixed an endless boot, and clearing a bloated temp folder was also recommended. On a DC-X6 with a very slow boot, the likely fix was a file system check followed by moving to or replacing the hard disk.

• Corrupted or wrong application software version
• The installer version does not match the system or OS (in one case the recovery would not install under Windows 10)

1. Confirm the software version and the OS the system runs
2. Try a different, correct installer version and do not keep retrying the same failing one

For the transcranial Doppler freeze, reinstalling the software was recommended and is a likely fix, not a confirmed one. For the failed recovery install, installing a suitable version of the software restored normal operation. Get software only from the manufacturer or another authorised source.

• A stuck or overfilled print queue
• A damaged or incorrect printer driver on the supplied disc

1. Open the print queue and clear it
2. Check the print settings and how the print key is assigned
3. Reinstall the printer driver from a freshly downloaded copy rather than from the original disc
4. Consider the printer connection type. Connecting by BNC instead of USB was suggested.

Clearing the print queue stopped the endless printing. Downloading the driver again to a USB stick and installing it from there got printing working. Both fixes were confirmed.

• Normal behaviour: the image gets coarser without the iBeam/iClear processing
• Normal image character of the SP5-1E probe on this system, which looks less 'polished' than on a DC-8

1. Compare the image with iBeam/iClear switched on and off
2. Compare against another probe (for example a convex probe) on a phantom
3. Where possible, compare with a similar probe on another system

In both cases the grain was confirmed to be normal behaviour, not a fault. No repair was needed. Explain the image-processing settings to the user.

• Electrical interference from the UPS or other nearby equipment

1. Run the system self-test
2. Unplug the UPS from the mains and check the image again
3. Move the system to another room, away from possible interference sources

Probable: the UPS or the surroundings were the source of the interference. Checking the UPS or moving the system was recommended; no outcome was confirmed. In the same case, the SP5-1E probe was reported as not supported on that DC-8 unit (built in 2015).

• Damage to the video output stage on the board that carries the HDMI output
• Possible damage to the video scaler

1. Inspect the HDMI connector and the board it sits on
2. Check whether the scaler was also damaged

Probable: replacing the board with a new one was recommended as the fastest and most reliable option. Repairing the board at component level was mentioned as an alternative. No outcome was reported.