help me, with Sniffer XR-71 (no sound)

[betobrambi]

Hello considered friendly, greetings from Mexico. It does few days, I bought to Stilian of Bulgaria, a new circuit of the Sniffer Xr-71, the circuit arrived very well, has a fuse of 800 mA….
I armed it and I get ready to create search coil without no problem. Nevertheless, my son by error, when he recharged the battery of the Sniffer caught, it and the apparatus stopped emitting sound.
I have reviewed the circuits, transistors and resistance it seems that it works well, only that any sound does not emit. I changed the horn and not yet it gives no sound…
I changed IRF 740 and seems that it is not the problem…
I removed the circuit of the box and I realized that a conductor of pcb was broken I repaired… it and seems to work correctly. But there is no sound still…
I reviewed fuse and I changed several times to them and there is no sound.
I was already hopeless because profit not to detect the problem.

Them attached a photography of the part that I repaired.


I am thankful for its aid and commentaries to them, although I know that they are going to me to reprimand by the error.
Friendly thanks mine.

heriberto

[Mechanic]

Hi Heriberto,

Can you upload better resolution images. I can't make anything out on the images you posted.

What was the voltage applied to the detector that caused it to fail?

[Morgan]

SNIFFER XR71

Hello considered friendly, greetings from Mexico. It does few days, I bought to Stilian of Bulgaria, a new circuit of the Sniffer Xr-71, the circuit arrived very well, has a fuse of 800 mA….
I armed it and I get ready to create search coil without no problem. Nevertheless, my son by error, when he recharged the battery of the Sniffer caught, it and the apparatus stopped emitting sound.
I have reviewed the circuits, transistors and resistance it seems that it works well, only that any sound does not emit. I changed the horn and not yet it gives no sound…
I changed IRF 740 and seems that it is not the problem…
I removed the circuit of the box and I realized that a conductor of pcb was broken I repaired… it and seems to work correctly. But there is no sound still…
I reviewed fuse and I changed several times to them and there is no sound.
I was already hopeless because profit not to detect the problem.

Them attached a photography of the part that I repaired.


I am thankful for its aid and commentaries to them, although I know that they are going to me to reprimand by the error.
Friendly thanks mine.

heriberto

hello

in the sniffer instrucions they warning this pulse detector cant be turned ON without the coil pluged in or with transformer connected to battery. I remember some other person in forum have this problem with Delta Pulse,and it was the mos fet transistors burned.
Anyway,i think you must send email to the person who sold the sniffer(Stilian) i´m sure he know where is the PROBLEM,becouse you are not the first one who make this mistake...

regards

[Qiaozhi]

Hello considered friendly, greetings from Mexico. It does few days, I bought to Stilian of Bulgaria, a new circuit of the Sniffer Xr-71, the circuit arrived very well, has a fuse of 800 mA….
I armed it and I get ready to create search coil without no problem. Nevertheless, my son by error, when he recharged the battery of the Sniffer caught, it and the apparatus stopped emitting sound.
I have reviewed the circuits, transistors and resistance it seems that it works well, only that any sound does not emit. I changed the horn and not yet it gives no sound…
I changed IRF 740 and seems that it is not the problem…
I removed the circuit of the box and I realized that a conductor of pcb was broken I repaired… it and seems to work correctly. But there is no sound still…
I reviewed fuse and I changed several times to them and there is no sound.
I was already hopeless because profit not to detect the problem.

Them attached a photography of the part that I repaired.


I am thankful for its aid and commentaries to them, although I know that they are going to me to reprimand by the error.
Friendly thanks mine.

heriberto

The fact you have a track on the PCB burnt out, makes me suspect you connected the battery the wrong way round. In that case you should first measure all the power rails, as the most likely components to have failed will be the ones in the power supply.

[betobrambi]

thanks for your help

Thanks for its aid, my friendly…
I answer Mechanic… Thanks my friend. Look that I solved the problem…
If you like, I raise the images with greater resolution… They were several things…
In one of them, a track of pcb was burned I united and it with a piece of copper wire.
Another detected problem is that the connection of the coil, had a false contact in the weld
in pcb and the jack of the chassis. Mosfet IRF 740 was damaged I changed and it, (very difficult to weld pcb of double plate).
Finally, comment great Morgan friend who already I requested aid to him to Stilian and I could solve the problem.
Qiaozhi, friend, thanks for your suggestions. It hears, that material could use to repair the fracture (breakage) of pcb…?
The tension of 12 feeding was and is v.
But now, that no longer I have problems with the audio one…
the sound of the threshold is not stable… him jam the RESET and it does not pass anything… That is to say,… it would have to be listened to: tatattatata… but hears… tatatatatata beeeep thus tatatatatataa beeep…
I move the potentiometer of the threshold and increases or it is reduced, but there are no changes… is not stable… is cut into…

The threshold will have been damaged (potentiometer) or another thing…
How I can prove good operation of the threshold or some of the potentiometers to know that they work perfectly?
Thanks for all their aid, friendly mine.
Them control a hug, Mechanic thanks, Morgan, Qiaozhi, greetings from Mexico
Heriberto