diff --git a/src/hw/efc.md b/src/hw/efc.md
index 6a9e4f7..a09c2d0 100644
--- a/src/hw/efc.md
+++ b/src/hw/efc.md
@@ -134,6 +134,6 @@ The destination is 0x5 in hexadecimal, which is 5 in decimal.
 
 Generally the error messages implies the data is malformed. For example, `received packet of an unknown type`.
 
-Either wrong clock source is chosen, or the calibration for DRTIO-over-EEM is incorrect.
-
-Verify the [clock settings](#clk-input). If they seem correct, it is likely caused by Kasli(-SoC) having an improper calibration for DRTIO-over-EEM. Consider re-doing the [flashing](#flashing) step.
+- Wrong clock source is selected, verify the [clock settings](#clk-input) is correct.
+- Bad DRTIO-over-EEM delay calibration value, re-doing the [flashing](#flashing) step.
+- Faulty EEM or clock signal cable, change the affected cable and re-doing the [flashing](#flashing) step.