Chance pi ne5534

[Mrbeen]

Hi
What can cause the ic ne5534 of chance metaldetector
Keeps on faling?
It makes me mad,could be the capacitors are next it?
I am beginner in electronics.
I apreciate your quick Help
Thanks

[Carl-NC]

If it's the preamp, check the flyback protection diodes.

[Mrbeen]

Thank mate ,I will check.
there is three diodes there.

[Mrbeen]

Hi
Diodes were ok,
Any new idea?

[dbanner]

Can you describe the failure? Does it work for a while, then fail? Or does it fail immediately?

[Mrbeen]

since I put a new mosfet on board,it start to work
for few seconds then stoped working properly,
I saw it taking too much electricity ,seems to have short some where.
The device makes some noise but can't detect any metal.
thanks for your attention.

[Mrbeen]

Hi the problems are fixed and it is working although
It does not go very far in the air test,
The frequency and since valve not ok
Probably 121 program got problem!!!

[surfdetector]

Hi the problems are fixed and it is working although
It does not go very far in the air test,
The frequency and since valve not ok
Probably 121 program got problem!!!

Just out of curiosity, what was the problem that you found? Somebody else might benefit from the answer.

[Mrbeen]

Hi
ok
In one occasion diod 4148 was definitely dead so I replaced it.
In other occasion transistor I replaced c945 and 5534 and
mosfets 9640 then devise came back to live.
Still working on them.
All the best