I tried two different tanks but I encountered the same problem.
I am using TBE buffer. After this situation, I tested buffer with ammeter and pHmeter, It seems conducting electricity and pH 8.6. How can i make sure about buffer composition?
Once I was supposed to be running a gel with TBE and accidentally used a buffer that was mostly just water, This vastly reduced the current due to the lack of electrolytes/salt to carry the charge.
Also if you make your own gels I would make a fresh one with the new buffer.
Is there anyone else running gels in your lab who could check that both rigs are working? Also try using a different power pack just in case one of the electrodes is damaged.