Full m/lab SD2000 schematics

[6666]

English?

translates to
Hello

[au1]

This thing works great!







Thanks Mechanic, Finderskeepers , Zed and anyone else that posted constructive help in this thread!

[Anis]

Thank you waltr for your replay, your advices are appriciated since it drived me to some major errors like soldering 1ohm instead of 13K for the resistor below LM358_A, setting BS170 instead of 2N7000, anyway I v been cheking all these thinks and it seams to be good.
So I v started again the +'-5V test and now it become the revers condition -5V is Okay, +5V = -0.4 and the 2N7000 becomes too hot!!!
Knowing that I m using BD675 ( I taked care about pinout) as replacement for ZTX688, PLEASE I M TOO CONFUSED, CAN ANY ONE ADVICE?

[Anis]

This thing works great!

[ATTACH]48615[/ATTACH]

[ATTACH]48616[/ATTACH]

[ATTACH]48617[/ATTACH]

Thanks Mechanic, Finderskeepers , Zed and anyone else that posted constructive help in this thread!

Keep up the good work, nice sweeting job...hope i will be on this lvl

[waltr]

Thank you waltr for your replay, your advices are appriciated since it drived me to some major errors like soldering 1ohm instead of 13K for the resistor below LM358_A, setting BS170 instead of 2N7000, anyway I v been cheking all these thinks and it seams to be good.
So I v started again the +'-5V test and now it become the revers condition -5V is Okay, +5V = -0.4 and the 2N7000 becomes too hot!!!
Knowing that I m using BD675 ( I taked care about pinout) as replacement for ZTX688, PLEASE I M TOO CONFUSED, CAN ANY ONE ADVICE?

Looking at the PS schematic again. Now see why I though the ZTX688 was up side down, it is shown correctly, -VB is lower than -5.

Not sure why you do not have +5.
The Gate of the 2N7000 should be pulsing, driven from the HEF4093.
Check that with your O'scope.

[Anis]

Looking at the PS schematic again. Now see why I though the ZTX688 was up side down, it is shown correctly, -VB is lower than -5.

Not sure why you do not have +5.
The Gate of the 2N7000 should be pulsing, driven from the HEF4093.
Check that with your O'scope.

Hi Waltr, I v checked the gate signal of 2N7000, please see what i got in the scope.
CH1 is for 2.5v test point
CH2 is for the gate of 2N7000

Dose the resistance of the inductance in this circuit affect the +5V? (see picture of my inductance)

[Mechanic]

Something like this should work. https://au.element14.com/bourns/rlb0...09238?st=150uh

I think from memory that the 5+ rail on the 2000 uses about 300mA or less.

Cheers Mick

[waltr]

Hi Waltr, I v checked the gate signal of 2N7000, please see what i got in the scope.
CH1 is for 2.5v test point
CH2 is for the gate of 2N7000

Dose the resistance of the inductance in this circuit affect the +5V? (see picture of my inductance)[ATTACH]48619[/ATTACH][ATTACH]48620[/ATTACH][ATTACH]48621[/ATTACH]

Also look with the scope on the 2N7000's Drain. This should be switching current through the inductor.

This is a fairly complex circuit- the lower part of the schematic seems to be where the +5V regulator is done.

What didoe is used on the 2N7000's drain?? The schematic I have does have a part number.

[waltr]

The Voltage at TP2, 2.5V ref, should not be switching.
And neither should the cathode, pin 1, of the diode.
Is the 100uF cap installed correctly?

Possibly you have the wrong inductor as Mick suggested.

[au1]

So I v started again the +'-5V test and now it become the revers condition -5V is Okay, +5V = -0.4 and the 2N7000 becomes too hot!!!

I experienced the same issues. In my case the problem wasn't in the power supply. First you had a problem with -5 volts but now have a problem with +5 volts.
This, and the fact that you have no sound, leads me to suspect you might have a problem somewhere else. If possible, disconnect your sound board. If possible, remove all your
front end receive IC's. Then check voltages again. With unit powered up, check 6+ / 6- where it connects to board. What size wire are you using between battery and board?

[Anis]

Hello genius people, @ first I would like to thank everyone for all advices, now I m glad to hear that magic sound, after many tests it was 2 problems: bad 2N7000 that I v replaced with 2N60C, and the bad inductor that I v replaced with one from a broken power adapter, after calculation it was about 180uH, and with these it works well,

BUT, I m just hearing sound and no reation from the coil,
Please I need your help to fire on this piece of over engineering...

[waltr]

Making progress.
No idea what else is wrong. Hope the others can help.

But first give some hints:

Use O'scope and check that coil is pulsed.
RX op-amp see Coil signal, etc.

[Anis]

Making progress.
No idea what else is wrong. Hope the others can help.

But first give some hints:

Use O'scope and check that coil is pulsed.
RX op-amp see Coil signal, etc.

Hi Waltr,
Please I v attached some pic from the mainboard signals, each picture named with part and pin.
I count on you and anyone to help me on this project.

All my respects
J.Anis

[Anis]

Follow:

[dbanner]

Looks to me you've got some timing pulses going(4066)

You certainly took on quite a challenging project.
I would start by breaking down the schematic into its contituent groups/functional areas.
Then troublingshooting each section based on what you would be expecting to find versus what is actually happening.
Assuming you have made absolutely no errors in layout/parts placement and construction.

If you want guaranteed success, the you must draw a block/functional diagram of the schematic. That makes understanding of the entire circuit much easier and hence troubelshhooting becomes a rather straightforward excercise.