2 minute video question

[ln76d]

If so, should i remeasure with the PSU plugged in to the wall?

I beg you! Please remove that sentence

Ok look at the photo of your PSU at the previous page!
On the left are three wires, two white and one black - this is primary side of the PSU circuit (secondary of the transformer) - am i right?
On the right side you have three (three pin) connectors - this is secondary side of the PSU circuit - right?
Are you disconnected those before? Are you sure that's the right order?
If so, remember that order (or note) because as you can see on each is the different order of wires (green/yellow/blue).
Unplug the cables and measure DC voltage on each pin (total nine) and make a note with results.
This is your unloaded DC voltage of PSU.
You don't have to remove PCB or anything else, just cables.

 

[ReRibbon]

Yes, the secondary white black white goes to the circiut board of the PSU from the transformer.

Yes, those 3 (three pin) connectors are the secondary of the PSU.
The marked red circle connector is the secondary that goes to power  the board.  The yellow one is 48v. The blue one I believe was to the battery section that has been removed prior to my getting it.

Those two last reading , that I thought were the unloaded V measurements,  are from the red connector section. I did not measure the yellow or blue connections.

Photo attached (prior to resoldering everything)

I've gone back to the photos from before the caps were changed and all of them are oriented correctly.

 

[ln76d]

You need to measure again the voltage on +VDC, -VDC and you can measure (and check where it goes) "15V".
All refered to ground marked on photo.
Before you power up PSU, check with the beeper is there connection between ground point on pcb and grounding point on metal enclousure of your mixer.

 

[ReRibbon]

Wow! Thank you for the photo!

This should be measured while the PSU is unplugged? Or plugged in?

The 15 volts is for a T Feed mic power supply as opposed to 48v.

Which PCB am I to look for ground from please? PSU? Where power is plugged to the module?

 

[ln76d]

This should be measured while the PSU is unplugged? Or plugged in?

Plugged in what? The Wall  from primary or do you mean the rest of the modules from secondary?
If the first option - don't even ask If the second - with the modules disconnected.

The 15 volts is for a T Feed mic power supply as opposed to 48v.

Ok, great feature!

Which PCB am I to look for ground from please? PSU? Where power is plugged to the module?

Do you mean the beeper i mentioned before or what?

 

[mjrippe]

This should be measured while the PSU is unplugged? Or plugged in?

Plugged in what? The Wall  from primary or do you mean the rest of the modules from secondary?
If the first option - don't even ask If the second - with the modules disconnected.

Disconnect power supply from all audio modules.  Plug power supply into wall AC.  Turn power supply on.  Keep your hands out of it!  Measure voltages at output of power supply from ground to positive and ground to negative.  This is your unloaded DC reading.  Does that clear it up?

 

[ReRibbon]

Shoukd i power the PSU and read the VDC reading from the outlet of the 3 pins marked with the red dot?

Yes with the beeper to see if the PSU is grounded to the metal. While unplugged,  I tried measuring from all three pins of the Red dot power out to the ground of the metal casing. Not grounded apparently.  No beep.

 

[ReRibbon]

This should be measured while the PSU is unplugged? Or plugged in?

Plugged in what? The Wall  from primary or do you mean the rest of the modules from secondary?
If the first option - don't even ask If the second - with the modules disconnected.

Disconnect power supply from all audio modules.  Plug power supply into wall AC.  Turn power supply on.  Keep your hands out of it!  Measure voltages at output of power supply from ground to positive and ground to negative.  This is your unloaded DC reading.  Does that clear it up?

Yes Sir! Thanks

 

[ReRibbon]

Unloaded voltage ground to V- is -17.22.
Ground to V+ reads +17.79

 

[ln76d]

DC Voltages looks ok to me.
At the photo of PSU pcb i marked two grounding points, you should check only these two points with beeper-  refered to console enclousure.
Since i don't see anywhere any wire to metal ground, it's probably grounded by the screw thightening PCB to the enclousure.
You should check this with properly mounted psu pcb inside the console.

What are the other  cable/wire connections on the channel board  except the powering cables (do some photo or video)?
After that we can back to the channel PCB and measure DC voltage on each opamp on the board.
Mount only one channel to do the test.
Download the datasheet for each opamp and check where are +V and -V points, some have different pinout than NE5532/LM833N.

 

[ReRibbon]

Ok; first if all thanks fir allllllll your help

! After checking the unloaded voltage,  i put everything back together.

It works. I dont know what happened or how it happened but it works. Meters are behaving. Audio passes and sounds AWESOME with the 5532's. I guess removing those resistors did in fact help them to eat juice and be awake..

Only issues now are Channel 6 passes no signal, channel 3 mic input worked but decided to stop, ch 1 (with 833n) sounds distorted like a Big Muff pedal, and audio only comes out of the right channel.  Left VU meter isn't reading

 

[ln76d]

Ok; first if all thanks fir allllllll your help

! After checking the unloaded voltage,  i put everything back together.

It works. I dont know what happened or how it happened but it works. Meters are behaving. Audio passes and sounds AWESOME with the 5532's. I guess removing those resistors did in fact help them to eat juice and be awake..

Only issues now are Channel 6 passes no signal, channel 3 mic input worked but decided to stop, ch 1 (with 833n) sounds distorted like a Big Muff pedal, and audio only comes out of the right channel.  Left VU meter isn't reading

Do you have any spec marked on the power transformer? Like for example how much "VA" it can worki with?
On channel six and three check which opamp is getting hot - if some is of course!
If there will be any hot opamp and in the same position on the working channels isn't - replace it, cause it's probably damaged.
If not, put 1kHz sine wave to the input and trace the audio path with multimeter on AC range. If you have scope, it would be better of course than multimeter. When the signal would be gone - this would be the damaged part.
Do some photos or videos of meter connections.
Change order of meters connection. Faulty one to the circuit of working one. You will now is that the driver damage or the meter damage.