IBM 5151 - Known Problems/Issues
SYMPTOM: No display
• Faulty 5151.
To get any display at all (including simply a raster), the 5151 requires that a horizontal sync signal is coming into the 5151 from an operating MDA video card.
Therefore, the following are possible causes as well:
• Not connected to an operating MDA video card.
• Poor connection to operating MDA video card. Includes oxide build-up on connector pins, etc.
• Faulty MDA video card.
• MDA video card has not been initialised. (Example cause: 51xx motherboard switch settings set to EGA, instead of MDA.)