AMB Laboratories DIY Audio

[grahamfocal]

Hi, I have just completed my build, and no life.
keeping it simple for a start, I have the red light on the switch, and when USB or COAX plugged in I get the green light.
The problem is, I get no o/p.
for starter is there a simple check for no output but a green light, The only issue that I have found so far is when boards are plugged in I get 1.7 volts instead of the 3.3
I have checked all the chips to be fine.
Anything to basically check for starters.
thanks,

[amb]

The low voltage should be a hint -- did you try reflowing the solder joints at the voltage regulator(s)? More than 90% of all γ1/γ2 problems are related to bad solder joints.

[grahamfocal]

Will try that first.

[MisterX]

One of the more common solder related problems is shorting one or more of the pads to the top of X1.

Did you perform a "sanity check" on the Y2 board before connecting it?
The test is similar to the Y1 board....
With the meter set to the lowest range, measure the resistance between the 3.3V, 4.5V and 5.5V test points and ground.
They should all read OL (or whatever your meter sez when the reading is out of range).

[grahamfocal]

One of the more common solder related problems is shorting one or more of the pads to the top of X1.

Did you perform a "sanity check" on the Y2 board before connecting it?
The test is similar to the Y1 board....
With the meter set to the lowest range, measure the resistance between the 3.3V, 4.5V and 5.5V test points and ground.
They should all read OL (or whatever your meter sez when the reading is out of range).

Hands up, no I didnt bought my kit to work, so will check that out, thanks.

[grahamfocal]

One of the more common solder related problems is shorting one or more of the pads to the top of X1.

Did you perform a "sanity check" on the Y2 board before connecting it?
The test is similar to the Y1 board....
With the meter set to the lowest range, measure the resistance between the 3.3V, 4.5V and 5.5V test points and ground.
They should all read OL (or whatever your meter sez when the reading is out of range).

regarding the 'shorting pad to top of X1' does the case of X1 go to ground (discovered that by accident) sorry as you can tell I am still learing on DIY projects.

how would I short the pads to the case?

[MisterX]

Meh......I guess I should have mentioned the top of the crystal is internally connected to the ground pin.

[grahamfocal]

One of the more common solder related problems is shorting one or more of the pads to the top of X1.

Did you perform a "sanity check" on the Y2 board before connecting it?
The test is similar to the Y1 board....
With the meter set to the lowest range, measure the resistance between the 3.3V, 4.5V and 5.5V test points and ground.
They should all read OL (or whatever your meter sez when the reading is out of range).

regarding the 'shorting pad to top of X1' does the case of X1 go to ground (discovered that by accident) sorry as you can tell I am still learing on DIY projects.

how would I short the pads to the case?

May have found the issue. X1 pad to bottom right (as you read the text on it) is shorted to the case.
Is that a simple case of too much solder leaking around the isolation pad on the underside and touching the case?

Will that also be the reason why I am only getting (have not reflowed the voltage reg yet) 2.02volts on the 3.3 test pad?

[grahamfocal]

Meh......I guess I should have mentioned the top of the crystal is internally connected to the ground pin.

thought that I had it with that one.

Still, will try reflowing regulators later on, as only got 2v on that test pad.

[MisterX]

What's the resistance between the 3.3 test point and ground?