[yudamn]

Hey All.  I've put together the compressor and everything is working as it should.  I've already used it on a couple mixes.  The only problem I seem to have is that the light on the meter isn't working.  At first, it didn't even dawn on me that it had a light (must've skimmed over that part in the guide).  The In led works fine, it's just the light for the meter.

Any suggestions on specific things to look at?  Thanks in advance.

[JPK]

Check if the DC voltage comes to the LED pins on the meter. It is the 2 smaller pins.

[yudamn]

Tested with power on, in button on

From V- to Blue: 53.6, From V- to Yellow: 173
From V+ to Blue: 31.98, From V+ to Yellow: 31.85
From Blue to Yellow: 153

[JPK]

From Blue to Yellow: 153
153 what? millivolts?

[yudamn]

Sorry about that.  Retested.  Blue to Yellow is 16V

[JPK]

If the yellow/black wires are in the correct position (please double check at both ends) then the meter LEDs are dead.
Contact me here for a replacement.

[yudamn]

Can you tell me what controls the needle on the meter?  I've replaced the meter and everything worked perfectly fine until a couple days ago.  The light is still working, however, the needle no longer moves.  I can hear the compressor working, but there is no visual feedback.  I'm wondering if one of the components burned out or something, but which one should I be looking at?

[JPK]

First thing to check is the meter connector. Make sure the contacts are inserted the right way round with the latch in the side rectangular hole.
The meter is controlled by U21 pin 1 via the trimmer T4 and resistor R100. The FET Q1 inhibits the meter when the compressor is bypassed.

[yudamn]

Hi.  I've tried to live without the meter working, but it's beginning to get to me. It's the same issue, the compressor works, the meter lights up, but the needle doesn't move.  I've checked that the meter connector is properly connected.  Also the meter worked for weeks before it stopped.  Is there something specific that I should be looking for?

[JPK]

First check that the meter is working by measuring its internal resistance (connector unplugged). This should move the needle. Around 600 ohms.

[yudamn]

First check that the meter is working by measuring its internal resistance (connector unplugged). This should move the needle. Around 600 ohms.

I'm not sure I know how to do this.  Do I just remove the unit from the chassis, and connect my ohm meter to the red and black terminals of the meter?

[JPK]

Yes, after disconnecting the meter connector.

[yudamn]

I'm getting 617 ohms

[JPK]

Does the needle move when you take the measurement?

[yudamn]

Does the needle move when you take the measurement?

Yes it does. It moved to just below the 8db mark.

[JPK]

- Check the solder joints of CN4 and connector to wires connections.
- Check the solder joints of R100 and trimmer T4. Check the ohmic value of T4.
- Try removing Q1.

[yudamn]

checked all solder joints
t4 - 855Ohms
put a blob of solder on all legs of q1
even tried replacing the meter. 

same result. i can hear the unit working, but the meter does nothing. the light comes on, but that's about it.

[JPK]

Try removing Q1 and D18.

[yudamn]

Try removing Q1 and D18.

That worked! Thanks for the help.

[JPK]

You should replace these components.
The diode protects the meter against too larger voltages: BZX55C2V4-TAP
The transistor prevents the meter moving when it is bypassed: 2N7000
Two very common and cheap components.

[yudamn]

Just placed an order for these components. Again, thanks for your help!

[JPK]

Be carefull to ground your body when handling the 2N7000 (removing your shoes does the trick). It is very sensitive to static electricity.

[yudamn]

Update for anyone that may experience the same issue.  Replacing Q1 and D18 did the trick.  Everything is working now.

Thank you JPK!