For some reason my units are dropping like flies. In the past 24hr three units have burned the USB ferrite bead. I can't seem to make any connections for why this is happening, one unit has VOLT mod 1; two bridges, has been running for a month. The other two have "R-52 or R139" mod with 47k and 50k resistor, also been running stable for a month. None of the units shared the same USB hub so I crossed that off the list of possible failures, two shared the same power supply but the ferrite bead that burned is for the USB hense 5volts so not sure if that would have mattered. I am lost finding any correlations between the units that failed, possibly just a coincidence or a weak part, but its suspicious that 3 have failed in the past 24. We shall see, now have to order new parts and wait to get them back online.
That sucks. Very strange also. 3 different mods, 2 different power supplies. Same part blown on 3 boards. Tell us more about the power supplies you have.
Both power supplies are the 30amp LED power supplies, I have checked with a multimeter the barrel plugs for each unit, and steady 12.4 volts. The ferrite bead is the one next to the USB plug on the board labeled FB26. Does anyone know if FB25 is the same as FB26, I would like to try to desolder FB25 from one of them and plug it into FB26 to see if it starts hashing again before I order parts. Are ferrite beads directional or can they be placed any which way? Any tips on a way to check to see if they will hash without the bead, IE jump the pads just to check if they will hash? Thanks in advance for replies, I am frustrated about the death of 3 and am worried it may domino to the rest if it is something else not just a coincidence.
Poopy,
12.4V is too low compared to standard 'proper' 12V switch mode power supplies. 13.80 is the minimum voltage it should be outputting under load. More if not loaded i.e. not powering anything.
The FB's are acting as high frequency filters to compensate for crappy power being fed by crappy psu's like the LED type you are using.
I am sure it's the culprit!
You can temporarily bypass the unidirectional/non-polarized FB to see if your pod will power back up. There is a good chance that the FB blew because of an overload or dead short down the line.
It could already be a new brick
Good luck!
I would suggest not to jump ur FB. if u have a short circuit in ur gridseed it could damage ur computer USB port and other damage. I have 10 of them bricked! Found the PCB shorted. Disolder two PCB every single part to find the short! Which I believed sorted now.