Hi,my mother has a el-90, but yesterday, suddenly the sound went to a loud single dissturbent liked sound, and i can not make it go away, every works, like buttons and lights, but no more nsounds from the organ...how can i solved this?or how can i reset this organ?greatings from Hans from holland

if no indication of power, change fuse by opening the back cover....if its showing power consult a qualified tech.

sounds like either a blown amp circuit or you simply blew out the speakers, amp circuit is most likely.

If this occurs with no audio input, exercise your warranty immediately.

Likely the amp blew and the power supply is being overloaded and keeps trying to power on but finds an overload and continues as the power goes away. This is NOT a DIY unless your are electronically adept.

it sounds like an input jack or plug problem, first clean them with alcohol. try and clean the jack with a Q tip and alcohol.

The light means NOTHING other than a small voltage is getting to the unit. Verify the power supply is putting out the required voltage...

BUT FIRST...

A common cause of this is we forget which side is input and output... happens ALL the time, so verify you have the in and the out cables to the right placee.

The unit needs to be repaired. Since it is a thermal problem, you can likely find the bad part with circuit cooler. See if the volume control affects the loudness of the howl... If it does, probably an op-amp in the preamp before the volume control is sick. If it doesn't affect it, then the output amps are suspect. Also check the power adapter.

90 % of these types of problems are caused by faulty leads .... make sure that you have correct speaker cables and not just a regular guitar cable