All Arcom boards are thoroughly inspected and soak-tested before despatch, and so the likelihood of a board being faulty on arrival is small.
If the board has never worked, it is possible that it was damaged in transit, so please inspect it carefully for physical damage before proceeding with this guide.
Fault | Cause | Remedy |
---|---|---|
No picture. |
No power. | Check power to SG84 and monitor |
Faulty connector(s). | Check that the RGB signals are reaching the monitor. | |
Blank screen | Wrong initialisation. | Are you sure that you have sent the right bytes? |
Accesses to the board hang. | Wrong address. | Check that the address being used corresponds to bus or the jumpers in LK1 |
Faulty socket. | ||
Picture too large | Incorrect clock frequency or maladjusted monitor | Adjust clock frequency or monitor. |
Jumping picture | Wrong video standard | Is your monitor compatible with the video standard? |
Wavy picture | Bad syncs. | Check that you are supplying your
monitor with all the syncs it needs, and that they are of
the correct polarity. Check that they are reaching the monitor. |
Skewed picture | External EMI | Check that the monitor that you are
using is set up to work with standard U.K. line and frame
rates. Is the SG84 close to any sources of strong electro-magnetic interference (for example the monitor or a switched-mode power supply)? Try moving any possible sources away or shielding the board better. |
Skewed picture. | Bad ground. | A bad picture is usually the result of
an insufficient ground between the output device and the
monitor. Check that you have connected the ground from SG84 PL4 pin 8 to your monitor input ground (this is not necessarily the same ground as the monitors case). |
Frequency mismatch. | Check that your monitor is working at the correct frequency. |