Early Garrett help needed please

[ash]

Another new update

I have unsoldered the leads from the push button tuner in the handle. When i joined them,there was audio from the speaker. I was able to tune to threshold when in either disc mode,but in all metal the threshold just went loud and wouldn't lower. But when i stop these two leads from touching,the audio tone goes loud.
Any ideas folks. I guess the push switch could be at fault,but any other ideas would be great...............

[Altra]

Hi Ash,
So much for the LM358! Will it detect metal after you set the threshold in disc mode?

Mark

[ash]

I waved a pair of stainless pliers over the coil,and it was giving a signal. But it was very weak from a coin..

[ash]

One more thing. Sometimes when you turn it on,there is no audio,so turn it off again,then retun it on. Then the audio starts again. Plus sometimes the audio sounds like very fast pulsing,but it does detect metals. But not that far from the coil. Later on,the threshold sounded as it should. But then the machine would not detect the metal targets.
Any views on this please.
With it detecting metals,the coil seems to be ok. Yes.?
Any help would be welcome