In June I purchased the bitcoin merchant 3x Gekko Compac F combo with Raspberry Pi 4 preinstalled with cgminer.  I set and ran them at 400 MHz for two months before one mining stick failed.  I have since rotated their positions in the USB hub and the stick is still failed with blue on, red on, white off lites.  Is there additional troubleshooting?  Is there any warranty? Can the stick be repaired or should I just replace?  I am at 37,690 satoshi on Slushpool and can continue with the two stick miners.  I am a novice at desktop BTC mining.