Building the Geotech Barracuda Rev A (from silverdog)

[azigta]

Can you have a look at R7, R5, R16, no need to remove from PCB, just check the correct value.

Yes, I have checked them right now, the value is exactly what it should be.

[jladre]

Can you post again your latest photo of your board?

[azigta]

Can you post again your latest photo of your board?

Sure, But let me point some details xD The hot glue I used for holding those female round headers on the middle of the board is not conductive, there's also a wire sealed with hot glue that connects a leg of the right 2n5485 to a resistor on the left side of the board since I broke the trace and was easier for me to do it that way. It looks like part of the wire is exposed but it's really all covered in glue, you can't touch the wire. I checked for short circuits and there aren't any xD It was hard to do it, and looks bad, but it's actually very solid and stable. On the back of the board picture, r14 pads made short circuit with ground (you can see solder very close to the trace, because I acidentally broke the red cover outside the trace, (r14 is at the right in that picture) so I soldered it on the top side as you can see in the other images. Is tested and working, no more shorts. Again, looks bad but it works xD





By the way, you consider normal what happens with D1 and D2 diodes? You can read in post number 41. Thanks

[jladre]

[azigta]

[ATTACH]39003[/ATTACH]

But if I short the center pin to the upper pin wouldn't that disable the 10k potentiometer? I putted that because the third pin in pl2 is not connected, connecting it to pin 1 makes me able to connect the pot with 2 legs and not caring if I do center with pin 1 or center with pin 3. And having it connected this way I get the ohms reading on U4 pin 5 so it is connected the right way... Isn't it? Am I understanding wrong?

[jladre]

If you short the pin 1 and 2 you dont need to use the 10k pot. But if you like that the 10k pot still connected then do not short pin 1 and 2. You can short pin 2 and 3 but never short pin 1 and 3 of the pot.

[Qiaozhi]

By the way, you consider normal what happens with D1 and D2 diodes? You can read in post number 41. Thanks

The two diodes you mention are connected across each other, with the anode of one connected to the cathode of the other. So (of course) you will get conduction in both directions.

[azigta]

The two diodes you mention are connected across each other, with the anode of one connected to the cathode of the other. So (of course) you will get conduction in both directions.

Thanks, I was worried about it

[azigta]

If you short the pin 1 and 2 you dont need to use the 10k pot. But if you like that the 10k pot still connected then do not short pin 1 and 2. You can short pin 2 and 3 but never short pin 1 and 3 of the pot.

I shorted Pin 2 and 3, and connected the pot on pins 1 and 2, the problem persists. I get same detection depth

[jladre]

Try to change all your pot with a new one if you dont know how to test it for bad pot.. use multimeter (resistance test) put the probe on pin 1 and second probe to the 2pin then turn the put if it give a good reading then do the same to 2pin and 3 pin.. test all the pot.

[azigta]

Try to change all your pot with a new one if you dont know how to test it for bad pot.. use multimeter (resistance test) put the probe on pin 1 and second probe to the 2pin then turn the put if it give a good reading then do the same to 2pin and 3 pin.. test all the pot.

Thanks, I already did that before, but I didn't post it here, sorry. I tested the pots but anyway I changed them because I was desperate xD But then user 6666 told me how to test if the pots were working on the circuit by measuring pin 5 on U4 and both the r14 and the 10k pot (also threshold pot) work as expected.

[jladre]

Do you have extra 40106? Try to swap. This problem is easy to solve if we has just access to it personally.

Also double check the pinout of all transisor..if you used equavalent then refer to its pinout.

[azigta]

Do you have extra 40106? Try to swap. This problem is easy to solve if we has just access to it personally.

Also double check the pinout of all transisor..if you used equavalent then refer to its pinout.

Hi, I don't have another 40106 but I'll buy it. I didn't use equivalent transistors, so the pinout is ok.
It could be that 40106 is bad, I tested it by looking at the pinout and measuring continuity on each gate, every gate looks ok but maybe there are problems inside it that I can't understand or measure. Tomorrow I will try to buy it.

[jladre]

Also have an extra irf9640

[azigta]

Also have an extra irf9640

Ok, thanks