[BUILD] New FET/RACK Official Help Thread - Please read first post!

[Jacob123588]

You said it doesn't turn on but you were able to test the voltages accurately?  That would not be possible.

Confirm your fuse is in and not blown, confirm your voltage select switch is set correctly, confirm your DMM is set to AC V.

Mike

I tested the power supply. It was all good, so I continued pressing on. I had finished assembly and I was getting ready to calibrate, when I pressed from off to GR, no lights no needle movement, nothing so I plugged in some signal still nothing. So I figured I'd test the power supply again, and the ground reads good, 0.2. 30v reads 0 and -10v also reads 0.

 

[Echo North]

I tested the power supply. It was all good, so I continued pressing on. I had finished assembly and I was getting ready to calibrate, when I pressed from off to GR, no lights no needle movement, nothing so I plugged in some signal still nothing. So I figured I'd test the power supply again, and the ground reads good, 0.2. 30v reads 0 and -10v also reads 0.

Is your fuse blown?

 

[Jacob123588]

Is your fuse blown?

No.

 

[Echo North]

No.

If your fuse is not blown then something has changed since you last tested it.

Make sure all of your L brackets are installed and look for suspicious solder joints, bridges, bad connector connections.

You're just going to have to go over with a fine toothed comb.

Mike

 

[Echo North]

Disconnect the 5 pin power header from the main PCB and see if you can measure the AC V between the middle yellow wire and each of the orange wires. Common probe on yellow.

Again disconnected from he PCB. You'll need to have thin meter probes to get in the connector.

Be very careful.

Mike

 

[Jacob123588]

Disconnect the 5 pin power header from the main PCB and see if you can measure the AC V between the middle yellow wire and each of the orange wires. Common probe on yellow.

Again disconnected from he PCB. You'll need to have thin meter probes to get in the connector.

Be very careful.

Mike

Where exactly am i putting the probes? In the in the connector? If so, they don't fit.

 

[Echo North]

Where exactly am i putting the probes? In the in the connector? If so, they don't fit.

Yes.

Not much I can say if your unit won't power up, the fuse it fine, and it was working early.  I'd have to look at, but obviously there is a cost to that. 

If you're super careful, you can disconnect the power transformer from the IEC and test the AC  V where the black connect would be (bottom tab) against the chassis ground.  You should have 120V AC there.

That's mains voltage so be very careful.

Mike

 

[Jacob123588]

Yes.

Not much I can say if your unit won't power up, the fuse it fine, and it was working early.  I'd have to look at, but obviously there is a cost to that. 

If you're super careful, you can disconnect the power transformer from the IEC and test the AC  V where the black connect would be (bottom tab) against the chassis ground.  You should have 120V AC there.

That's mains voltage so be very careful.

Mike

I do have power coming in! I got a reading of 126.5 AC Volts. That sounds high.. but that's testing the IEC

 

[Echo North]

I do have power coming in! I got a reading of 126.5 AC Volts. That sounds high.. but that's testing the IEC

Connect everything back like it should be, including the secondary of the power tx.

Now measure the AC at the secondary with the unit on (GR Mode). Test each of the orange wires compared agains chassis ground. You can test on the PCB since it's connected now.

What do they read?

Mike

 

[Jacob123588]

Connect everything back like it should be, including the secondary of the power tx.

Now measure the AC at the secondary with the unit on (GR Mode). Test each of the orange wires compared agains chassis ground. You can test on the PCB since it's connected now.

What do they read?

Mike

They both read 0....

 

[Echo North]

So your mains supply voltage is dying between your IEC inlet and the PCB.

WITH THE UNIT UNPLUGGED. NO POWER.

1 . Measure the DC resistance (Ω) between the yellow wire and each of the oranges.
2. Measure the DC resistance (Ω) between the two outer pins of the 3 pin connector at the top of the voltage select PCB.  You can remove the header to get at the pins.

For both measurements you need to have the 5 pin secondary and 7 pin primary power TX headers plugged into those PCBS.

Mike

 

[Jacob123588]

They both read 0....

The orange wires read 11.3 and 11.4
The putter wires on the 5 pin read  11.4

The 3 pin connector will not give a read.

 

[Echo North]

The orange wires read 11.3 and 11.4
The putter wires on the 5 pin read  11.4

The 3 pin connector will not give a read.

What about the DC R between the two voltage select switch pins on the left side of the V select PCB (looking from the front of the compressor)...again two left pins top and bottom.

No power, make sure the 7 pin connector is plugged into the same PCB.

 

[Jacob123588]

What about the DC R between the two voltage select switch pins on the left side of the V select PCB (looking from the front of the compressor)...again two left pins top and bottom.

No power, make sure the 7 pin connector is plugged into the same PCB.

are you talking about the 2 pins connected to the IEC? The 2 left pins on the IEC give no read, the 2 right pins on the IEC give a read of 1.1.

None of the pins on CN14 on the V Select PCB give a read no matter which configuration I try.

 

[Echo North]

are you talking about the 2 pins connected to the IEC? The 2 left pins on the IEC give no read, the 2 right pins on the IEC give a read of 1.1.

None of the pins on CN14 on the V Select PCB give a read no matter which configuration I try.

You've either got an issue with you V select PCB soldering, the switch itself, or you power transformer (which would be weird).  You could try flipping the switch to 230 then back to 115 to see if the switch is just un seated.  Then try re flowing those joints on that PCB.

If that fails you'll have to email us.  You'll probably need to send in the power transformer so we can check it.

Mike

 

[Jacob123588]

You've either got an issue with you V select PCB soldering, the switch itself, or you power transformer (which would be weird).  You could try flipping the switch to 230 then back to 115 to see if the switch is just un seated.  Then try re flowing those joints on that PCB.

If that fails you'll have to email us.  You'll probably need to send in the power transformer so we can check it.

Mike

Ok let me try all of that and see what happens! Thanks for everything Mike!

 

[Jacob123588]

Ok let me try all of that and see what happens! Thanks for everything Mike!

Ok so just to be thorough, I resoldered Everything on  the V Select PCB, plugged everything back in, pushed the switch to 230 and back and powered to (GR) still nothing. Not even a smell or a smoke or nothin.

 

[Echo North]

Ok so just to be thorough, I resoldered Everything on  the V Select PCB, plugged everything back in, pushed the switch to 230 and back and powered to (GR) still nothing. Not even a smell or a smoke or nothin.

Send us an email with your address.  I'm going to send you a label to send in the V select PCB assembly and power transformer to test for you.

I *think* there may be an issue with your transformer.

Mike

 

[YoDudeRock]

Mike,
It still happens with GR off (full CCW, click) and GR on.    It does get quieter with compression on.  The needle bounces with when turning the Output knob (in +4 and +8 meter mode).    In GR meter mode, the meter doesn't move at all, so it seems like the noise or isn't going through the compression circuit.
Thanks!
Chris

That rumble is probably DC getting into the pot then. You shouldn't have DC in your pot, C7's job is to block that DC on the side. Though just because you have DC at the pot side of C7 it doesn't necessarily mean the DC is coming through the cap.  It could be come "backwards" from another location.

Do you get the rumble in GR OFF mode? (attack FCW)

 

[Echo North]

Mike,
It still happens with GR off (full CCW, click) and GR on.    It does get quieter with compression on.  The needle bounces with when turning the Output knob (in +4 and +8 meter mode).    In GR meter mode, the meter doesn't move at all, so it seems like the noise or isn't going through the compression circuit.
Thanks!
Chris

C7, C8, and C17 should prevent DC from getting into you pot.

Check to make sure there are no solder bridges in their leads, and if polarized, they are inserted right.

Mike