diff --git a/src/hw/zotino_fastino.md b/src/hw/zotino_fastino.md
index 8f72d98..29e4439 100644
--- a/src/hw/zotino_fastino.md
+++ b/src/hw/zotino_fastino.md
@@ -72,3 +72,7 @@ You can flash the gateware with a Kasli/Kasli-SoC, be it in the crate or standal
 5. Run `nix-shell -p python311Packages.pyftdi`.
 6. Run `cd kasli-i2c; python flash_fastino.py 0 EEM<number> write fastino.bin` where `<number>` is the EEM port number on the Kasli/Kasli-SoC side.
 7. If PG and FD LEDs are lit green, the Fastino is ready.
+
+### Fastino output is 10V
+
+Fastinos by default after power up output 10V on all channels if not driven by the test otherwise. Make sure the EEM ports are specified correctly in the JSON and the EEM cable is connected to EEM0 on the Fastino.