2 replies to this topic

[stroess]

Hi.
Anyone know what kind of LED is used in the AZ drive encoder of an ETX70AT, or where to get a replacement part ?
Mine's gone defective (0 volts, contrary to the Dec drive encoder LED which is showing 1.2 volts), resulting in a "motor failure".

Any kind help greatly appreciated, as it would be weird to dump a nice telescope just because of a defective part with a value of just $1.

Thx in advance - Robert

[jrcrilly]

Leds don't fail all that frequently, and when they do they rarely short circuit (which is the only failure that would rresult in zero volts across it). It's much more likely that there's a circuit problem elsewhere that is preventing power from being applied to the LED. You can prove that by removing the LED and measuring the voltage at the terminals. With no LED there the voltage will be high - probably either 12V or 5V. If it is still zero then you know that the LED is not the problem.

[stroess]

Dear jrcrilly,
thx for your valuable hint ... there was indeed a connection problem with the wires leading to the LED, not a failure of the LED itself. I could fix the issue, and the telescope now works like a charm again. I appreciate your kind help.
Regards - Robert S., Berlin, Germany