If a flow cell check on a MinION or PromethION flow cell shows that the flow cell has zero pores this is usually not a true reflection of the pore count. This is often caused by a bubble inside the flow cell sitting over the common electrode blocking the current running over the array.

If you see this you can try to resolve it with the following steps:

1. Remove the small air bubble from the inlet port, as you would before loading.
2. Add a small volume (20 – 100ul) of storage buffer to the flow cell through the same inlet port.
3. Run a flow cell check again.

You should see that the pore count goes up. If it does not go up, or does but is still under the warranty pore count, then please contact support.