Problem with building barracuda. HELP!!

[omr255]

Hi everyone!

I am new to this forum so please let me know if I do anything wrong.

I have bought a barracuda rev a set from silver dog and I am having some problems getting it to work. It seems as if half the board is not recieveing power as the speaker/buzzer has 0v on the pins.

I have also noticed the schmitt inverter only puts out .7v on pin 4 where on the instructions it states to try the buzzer. The lf412cn also outputs 1.5v on pin 8 instead of 5v.

Does anyone have any clue what could be wrong?

Thanks!

[kosacid]

upload a pic to the forum of the board also make sure you have had flow through on the holes sounds like a resistor out of place or a bad soilder

[omr255]

Here are the pictures of the board.

[ripsdevala]

Did you get 5v and -5v from 78L05 and 79L05 output?

[Qiaozhi]

Hi everyone!

I am new to this forum so please let me know if I do anything wrong.

I have bought a barracuda rev a set from silver dog and I am having some problems getting it to work. It seems as if half the board is not recieveing power as the speaker/buzzer has 0v on the pins.

I have also noticed the schmitt inverter only puts out .7v on pin 4 where on the instructions it states to try the buzzer. The lf412cn also outputs 1.5v on pin 8 instead of 5v.

Does anyone have any clue what could be wrong?

Thanks!

From your description, I assume you didn't read the Build Document where it says:

"If you go through the following steps carefully, and in order, you will have a greater chance of
ending up with a detector that actually works. Please do not proceed to the next step until you have
solved any problems encountered in the current step. If you get stuck at any stage during the build,
then seek help in the Geotech forums before moving on. Do not simply populate the whole board;
discover it doesn't work (which will be the most likely result) and then post in the forums: “I've
built the Geotech Baracuda, and it's not working. What's wrong?” .... as you will receive little
sympathy from other Geotech members.
To reiterate:
Please follow the instructions step-by-step."

[kosacid]

by the look of the board you need to buy some flux put it on your board and resolderer, you have not got flow through on a lot of the solider joints

[Qiaozhi]

by the look of the board you need to buy some flux put it on your board and resolderer, you have not got flow through on a lot of the solider joints

That's no so important, as the board has plated-through holes.

[chevesne]

I am at level 7 of the kit construction.
The sample delay is 20 us on pin 4 U4,
But the voltage on pin 1 U7 is -1.00v instead of -2.1v?
.
Worrying or not?

[Qiaozhi]

I am at level 7 of the kit construction.
The sample delay is 20 us on pin 4 U4,
But the voltage on pin 1 U7 is -1.00v instead of -2.1v?
.
Worrying or not?

As long as you get a voltage increase when a target is placed near the coil, then you should be ok to carry on. The voltage measurement is only a guide, and there may be some variation between different builds.

[chevesne]

Voltage increases , I continue the assembly.

Thanks for your reply.

[kosacid]

i also noticed the caps are in the wrong place

[silverdog]

i also noticed the caps are in the wrong place

looks like you mixed up 4n4 and 470n at least
472J100 = 4n7F
.47K63 = 470nF

[chevesne]

C5 seems big for a 6,8nF, but maybe it is provided for a high voltage.