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LA502 Optical Compressor / Re: Meter LEDs -12, -16, -20 are not lightning

« on: February 17, 2022, 11:44:48 AM »

Yes,  actually when the connectors are disconnected there is only a continuity between Cn1a 6&9 and Cn1b 4&5. And when they are connected there is also a continuity between Cn1a 9 & Cn1b 7.

2

LA502 Optical Compressor / Re: Meter LEDs -12, -16, -20 are not lightning

« on: February 14, 2022, 11:53:54 AM »

Continuity check between pads on Cn1a & Cn1b look good, and it seems that there is no short cuts between neighbour pads, which I can confirm visualy.

However, I noticed that when I put my DMM probes on : (I am counting from the top of the connector, where there is the round mark on the pcb) 
- Cn1a 1rst pad + Cn1b 8th pad : -20 LED is lightning
- Cn1a 2nd pad + Cn1b 1rst pad : -3 LED is  lightning.
-    "            "         + Cn1b 8th pad : -20 LED is lightning.
- Cn1a 3rd pad + Cn1b 1rst pad: -3 LED starts lightning a bit.
-    "           "         + Cn1b 8th probe : -20 LED is lightning.
- Cn1a 4th pad + Cn1b 3rd pad : -9 LED is lightning.
-    "          "          + Cn1b 8th pad : -20 LED is lightning.
- Cn1a 5th pad + Cn1b 3rd pad : -9 LED is lightning.
-    "          "          + Cn1b 8th pad : -20 LED is lightning.
- Cn1a 6th pad + Cn1b 8th pad : -20 LED is lightning.
- Cn1a 7th pad + Cn1b 4th or 5th pad : -12 LED is lightning.
-    "          "          +  Cn1b 8th pad : -20 LED is lightning.
- Cn1a 8th pad + Cn1b 7th pad : -16 LED is lightning.
- Cn1a 9th pad + Cn1b 8th pad : -20 LED is lightning.

It also seems to exist a signal continuity between Cn1a 9th pad & Cn1b 7th pad.

Is there something wrong with all of that?

3

LA502 Optical Compressor / Re: Meter LEDs -12, -16, -20 are not lightning

« on: February 11, 2022, 04:22:45 PM »

Maybe an issue with the connector CN1?

4

LA502 Optical Compressor / Re: Meter LEDs -12, -16, -20 are not lightning

« on: February 11, 2022, 12:05:04 PM »

Yes I've tried it, but it don't. The problem le still on the same LEDs.

5

LA502 Optical Compressor / Re: Meter LEDs -12, -16, -20 are not lightning

« on: February 11, 2022, 10:58:27 AM »

So, everything is ok.
Leds are all in the good position, and there is continuity between pins 5,7 and 9 of U8 and U9 (continuity on each others on the same IC and between both ICs).

6

LA502 Optical Compressor / Re: Meter LEDs -12, -16, -20 are not lightning

« on: February 10, 2022, 04:45:15 PM »

And for R36: 15,92 V on Left side / 2,47V on right side.

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LA502 Optical Compressor / Re: Meter LEDs -12, -16, -20 are not lightning

« on: February 10, 2022, 04:42:24 PM »

2,47 VDC on both sides.

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LA502 Optical Compressor / Re: Meter LEDs -12, -16, -20 are not lightning

« on: February 10, 2022, 02:32:48 PM »

Hi JPK, thank you for your answer.

I went over my joints, with a special care for those you mentionned, but for now situation is just the same, nothing changed.
Is there a particular value that I should check to have more information of the issue?

Thanks for your help ! 

Théo

9

LA502 Optical Compressor / Meter LEDs -12, -16, -20 are not lightning

« on: February 08, 2022, 03:36:16 PM »

Hi everyone.

I've just finished the assembly of this LA502 module and i'm now onto the calibration and setup step.

Power voltage seems fine, i'm getting +/-15,95 VDC. Compressor Check seems to be fine too, Gain and Peak pots seems to work as expected.

When I'm calibrating the Meter,  I can get the -3 / -6 and -9 LEDs lightning without any trouble while adjusting P4 / P5 and P6 trimmers at 10,6 / 7,5 and 5,3 VAC signals on output. But I can't get -12 / -16 and -20 LEDs ligntning at 3,72 / 2,4 and 1,5 VAC output.
On the other hand,  when I'm switching on "6" on the ratio switch and turning the Peak pot, these LEDs are lightning all 3 at the same time when reaching 0,60 VAC output. Same thing with a "20/limiter" ratio when reaching 0,56 VAC. P7/P8 and P9 don't seems to have any effect on the lightning (or not) of their respective LEDs.

I've already checked my solder joints and reflowed a couple of suspicious joints, but nothing changed. 
Any ideas ?

Thanks!
Théo