Antminer S21 – PSU Overcurrent Protection
overcurrent protection triggered
Critical — Immediate action required
Symptoms
- Miner powers on briefly then shuts down
- PSU clicks repeatedly
- LED blinks then goes off
Step-by-Step Fix
Disconnect all hashboard power cables from the PSU.
Reconnect one hashboard at a time and power on to identify which board triggers OCP.
A board that triggers OCP likely has a short circuit — do not continue using it.
If OCP triggers with no boards connected, the PSU itself is faulty.
Check that you are using the correct PSU model rated for the S21 power draw.
When to Seek Professional Repair
If the steps above do not resolve the issue, or if you are not comfortable performing these repairs yourself, professional service is recommended. Attempting advanced repairs without proper equipment can cause further damage.
Related Error Codes
Still Having Issues?
Our team of Bitcoin Mining Hackers has been repairing ASIC miners since 2016. We have seen it all and fixed it all. Get a professional diagnosis.