First Texas Fisher, Bounty Hunter, and Teknetics HELP

[ivconic]

Sorry, but I've been avoiding personal contact lately.
I have serious private problems and I don't have time or focus anymore for these topics.
Maybe in the future when this bad period is over... if ever.
But that's why you have a forum, a public place, where a large number of people can help you with their knowledge.
I will be here more out of habit to quietly follow the activities on the forum, whenever I have the conditions to do so.
I apologize once again, but this is beyond my capabilities.

[Daves]

From 2006 when I registered on the forum, until today; I have tried to contribute to the forum by posting most of what I have.
All "my files" are scattered all over the forum. On various topics. It's a lot.
It would be better you to start reading the forum from the beginning, to see all the big topics, because a lot of work has been done there.
In the meantime, the forum has become gigantic and it is very difficult to navigate. But you have a "search" option that makes it much easier.

ivconic I need to contact you. I want to explain the issue privately, but I cannot send a private message to your profile.

[ivconic]

From 2006 when I registered on the forum, until today; I have tried to contribute to the forum by posting most of what I have.
All "my files" are scattered all over the forum. On various topics. It's a lot.
It would be better you to start reading the forum from the beginning, to see all the big topics, because a lot of work has been done there.
In the meantime, the forum has become gigantic and it is very difficult to navigate. But you have a "search" option that makes it much easier.

[Daves]

Ivconic, can you share your files? (detector diagrams, tx drivers, pcb pictures etc.)

[Sean_Goddard]

Have you checked the supplies?

[ivconic]

[ivconic]

Ok, I've tried various things, comparing the detector that is working (it's just a bad keyboard) to this one that
is not working (and has keys instead of a soft keyboard) and I can't find the problem.
Everything I check on both; agrees.
A video can speak more than 1000 words, here is a mix of a couple of videos:

[Carl-NC]

I don't know why the enclosures are different since they both have wired coil connectors. That was long before I arrived.

U1 (supposedly TS971 on your schematic) is small SMD 6 pin chip.

The LT6230 was used in the 1st-gen circuits. Then changed to the TS971. I don't have the old schematic.

But Black is going only up to C4 and further I can't trace it.

Black should be connected to ground. The (-) input of U1 should have an RLC circuit to ground, though I don't know the order. It's possible there is no L2 in the 1st-gen design.

Yes, you would tie /EN to V-.

[ivconic]

U1 =LTAFJ =LT6230CS6

That makes more sense now, thanks!
So, the ENABLE pin 5. is probably tied to pin 2. (V-) normally?
Or not?

[walter]

U1 =LTAFJ =LT6230CS6

[ivconic]

No easy job for me.
TX is alright, I changed Q1 anyway. Same thing. I get nice sinus 9Vpp on the osciloscope.
Schematic of TX matches and everything looks fine.
However... RX is confusing, not matching the situation I have on pcb here.
U1 (supposedly TS971 on your schematic) is small SMD 6 pin chip.
I downloaded TS971 datasheet and there is no 6 pin package described in it.
Observing your schematic i can trace some of the traces.
Red goes through C1 (no L1 from schematic ???) directly to "+" (I assume it is "+") input of the 6 pin chip.
But Black is going only up to C4 and further I can't trace it.
If take that Red goes to pin 3. then previous to it logically should be pin 2.
At 6 pin case then on the other side there are pins 4, 5 and 6 by common logic.
So Black should be connected to pin 2. through the R3 (it is present and ok), L2 (not existing on pcb) and C4 (present and ok).
But the other side of C4 I am not able to trace with simple buzzer.
PCB does not look broken nor any trace too.
Just for the sake of experiment I added a wire connecting the othe end of C4 with pin 2.
Switching ON and after boot sequence it starts cackling like a chicken.
Before that , forgot to mention; with buzzer I discovered that pin 2. and pin 5. are connected togather (probably bellow the chip, since I can't see the trace) or the chip is burned and shorted those two pins.
So the problem is in RX.
Would be easier if I do know for sure what the 6 pin chip really is?
And its pin assignments.
That part is not matching with schematic.

[ivconic]

The design was changed at some point to use a proper 1/4" headphone jack and to surface mount the coil connector...

Thanks!
But have you payed attention on details on photos above?
On both there is 1/4" hp jack and on both coil connector is NOT surface mount, but connected with wires.
Differences are in volume and shapes of enclosure. So visible if you pay attention.
Click on photo to get hires one. Easier to spot the differences.

[Carl-NC]

RX input:

[Carl-NC]

The design was changed at some point to use a proper 1/4" headphone jack and to surface mount the coil connector.

Here is the TX schematic. Test point 8-1 should be a pulse from the micro at ~19kHz.

[ivconic]

But the story doesn't end there...unfortunately for me.
I got that detector in an exchange a couple of years ago.
Even then it had some damage.
The headphone jack was destroyed and the audio out transistor burned.
I connected the dots on the pcb so that the audio works without the presence of the jack and replaced the transistor with one in a TO-92 case and
finally got clear and loud audio.
Now that there is coil; for the sake of order, I also tried the detection.
Alas! Almost does not work, almost no detection.
Detection barely happens only when I literally rub a coin (or some other object) against the surface of the coil.
I checked the connections of the coil connector to the pcb, everything is fine, everything is correct.
Everything looks to me as if the TX transistor is also burnt.
It is SMD. I haven't measured or changed anything yet.
Because I didn't have time for further work at that moment.
But there is something else interesting that I noticed!
Both detectors are Eurotek Pro. But their cases are slightly different in design!???
Carl do you know anything about that?
Is it a Chinese copy, one of the two?
Or did Teknetics decide to change the design a bit in a new series?
The latter seems pointless to me, an unnecessary expense, to change the housing molds around such small and unimportant details?