I am using the Aoyue 2900 digital soldering iron
(220V version) but having problems with it.
I used it quite heavily before the problem occurred, typically set at 470C. And it worked beautifully . . .
But now, if I go above 460C, it just keeps beeping at me. Sometimes even at ~430C it has trouble keeping its temperature constant - even once when I wasn't soldering anything! Originally it was very fast getting to the right temperature, but now its like the temperature control algorithm is going whack, sometimes overshooting the temperature.
On 3 different occasions it reported I think 938C (if I remember the exact value correctly). Obviously impossible as it can't go above 480C.
I suspect a problem with the temperature sensor as it still solders just fine.
Anyone with ideas? The manual doesn't mention this problem, but suggests using a multimeter to measure resistance on the tip . . . I don't own one at the moment so checking other ideas first . . .
The Aoyue repair shop will probably charge only ~$15, but it's like a hour trip away. Hoping I can identify the problem first . . .