Aion Andromeda Kit - No sound

[Ramil78]

Hi
Just finished with Aion Andromeda Kit.
No sound. Here is my readings :
IC1 (upper)

1 4.69
2 4.38
3 4.30
4 0
5 3.78
6 0.23
7 0.23
8 8.78

IC2

1 4.37
2 4.37
3 5.92
4 0
5 4.35
6 4.37
7 4.38
8 8.79

My knowledges are too low to find out what is a problem, but I understood that 6 and 7 on the First one is too low.

Need advice !
Thanks !

[bluebunny]

Welcome!  Can take a photo of the underside of your board and post back here please?

For everyone else, here's Kevin's build documentation.

[Ramil78]

Hi, thanks
i did it by the book all according manual

[duck_arse]

also welcome.

can you pull the IC's from the sockets and then measure the voltages on the socket pins, please? there is someting wrong at pin 3 on IC 2 as well, that voltage should be lower, not higher. we also need to know the voltages on the transistor pins, and at VA and VB.

[Ramil78]

Hi
Here you are measurements without ICs

IC1 (upper)

1 0,295
2 0,333
3 4,333
4 0
5 3.908
6 0
7 0
8 8.88

IC2

1 4.24
2 4.33
3 5.27
4 0
5 4.22
6 1,366
7 1,34
8 8.88

Sorry for stupidity, but what is VA and VB ?

[antonis]

what is VA and VB ?

VA is the power supply (9V - Schottky diode voltage drop) where VB id the bias supply (VA/2 here..)
(VB also serves as AC ground, like for LEVEL pot lug 1..)

[Ramil78]

Got it  )
Without ICS

VA 9.09 V
VB 4.38 V

With ICs

VA 8.15 V
VB 4.35 V

[duck_arse]

your empty voltages show there is a problem. IC2 pin 3 can't be higher than VB, cause it's fed from VB. also, empty socket means IC2 pins 6 and 7 should be 0V, or wobbly floating wishy washy nothing, they are AC coupled away from any DC.

power off, IC's out of sockets, multimeter set to low ohms range, probe about those empty socket pins, see if there is a low resistance between pins or ground somewhere.

I also think there should be no voltage change at VA with/out ICs fiteed, cause there is only the schottky there [I might be wrong thinking Vf versus current, tho].

[Ramil78]

Thanks Stephen
Here you are
IC1 (upper)

1 Cannot measure this one , its jumps from 0 to 10 Mohm constantly
2 490 khom
3 18 khom
4 0
5 154 khom
6 241 ohm
7 236 ohm
8 3,14 khom

IC2

1 37 khom
2 17 khom
3 29,3 khom
4 0
5 41,6 khom
6 9,5 Mohm
7 8,98 mohm
8 3,16 khom

[duck_arse]

there is deffo a problem somewhere around IC1, pins 6 and 7 should be Megohms, not hundred ohms. you will need someone smarter than me to point out what it might be, though.

[Marcos - Munky]

IC1 (upper)

6 241 ohm
7 236 ohm

Just to be sure. Are those measures the resistance from pins to ground? Then we have a connection between those pins and ground. I can't really see what could be causing this on your photos.

Could you reflow solder joints on pins 6 and 7 (ic1), and also on C21 and R26 (both pins for them), and them post again the measured resistance to ground of each those 6 points (2 ic pins and also cap and resistor pins)?

Btw, while this is not related to your issue, that 3pdt should have a bit more solder on it. You don't need to use a lot of solder, but you should use enough to at least fill the pcb holes.

[Ramil78]

Hi Marcos
Sorry , was away from home and summer you know
Here you are some new  readings that you asked .
IC1 (upper)

1.  346 kohm
2.  1.06 mohm
3.  18 kohm
4.  0

5.  151 kohm
6.  11.7 ohm
7.  11.7 ohm
8.  2.45 kohm


IC2

1.  35.8 kohm
2.  16.7 kohm
3.  28.7 kohm
4.  0

5.  41 kohm
6.  378 kohm
7.  0.6 Mohm
8.  2.47 kohm


C21
390 kohm
0

R26
8 mohm0
35 kohm


Here are a few things to say :
Sound goes through even without power, LED light full powered on bypass, and half powered on ON mode.
No sound on ON mode.

Thanks for help !

[Yupnitski]

Hi!
As said before, there's definitely something wrong with IC1 pins 6 / 7. According to your measurements it seems that they're connected to GND directly. So, I'd check the whole board with a magnifying glass just to make sure there are no solder bridges.
And what comes to the notes about the led...well, that's not how it's supposed to work either. When in bypass mode, the led should be off. Somethings shorting the cathode side to GND before the switch (short in the wiring or a solder bridge?) It seems the insulation of the wires soldered to the switch board have melted a bit. It could be that some of the wires are shorted in- or outside of the insulation. Also, if the led is not burning as bright when the effect is switched on there's something connecting to GND. Is the led dim only when the IC's are socketed or without the IC's? Since with the IC's socketed you have 1V drop in the supply. That would make the led act that way.
You have checked the board-to-board wirings? They go point to point like they should? Just buzzing around the obvious things here