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Troubleshooting midiphy SEQ v4+


latigid on
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I could not see your picture of the soldering

As the behaviour is common to a column (two columns, but they are only separated by RJ4/8) it is probably caused by

1. Wrong transistor type or otherwise an error with T16. Yep, that's on the top side of lemec_L!
2. The pin driving T16, so R16 and IC4, pin 15. With luck you just have a solder bridge to +5V (pin 16).

Good luck!

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27 minutes ago, latigid on said:

2. The pin driving T16, so R16 and IC4, pin 15. With luck you just have a solder bridge to +5V (pin 16).

 

I tried soldering a bridge between pin 15 and pin 16 of IC4 and no luck. The 4 leds still light when seq_l is loaded. I presume thats exactly what I was meant to do?

I just have to remove the switch caps and light shields to be able to separate the boards again I presume?

Cheers!

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41 minutes ago, Smithy said:

I tried soldering a bridge between pin 15 and pin 16 of IC4 and no luck. The 4 leds still light when seq_l is loaded. I presume thats exactly what I was meant to do?

What I meant was to desolder a potential bridge there. Generally you don't want the output shorted to the power supply. But a constant voltage here would mean that the transistor base was always in the high state and not able to switch as required with the 595 pulses.

 

41 minutes ago, Smithy said:

I just have to remove the switch caps and light shields to be able to separate the boards again I presume?

I guess that's the case... light|shields and keycaps can stay on!

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28 minutes ago, Smithy said:

fixed the image.

Thanks, it works. Can't see anything obvious. You can check the components I mentioned before. It could also be a too-long resistor leg, also on RJs? Before desoldering all of the switches, you might try to remove those resistors.

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1 hour ago, latigid on said:

Thanks, it works. Can't see anything obvious. You can check the components I mentioned before. It could also be a too-long resistor leg, also on RJs? Before desoldering all of the switches, you might try to remove those resistors.

I trusted my cutting of the RJ leads and went ahead and de-soldered all the Mattias switches in the Lemec PCB.
Turns out there was a short between the bottom leg of T16 and the unused pad to the right of it!

Thank god for my desoldering station otherwise this would have taken much longer, if i could even do it all with a manual pump!

IMG_20210526_212922.thumb.jpg.82b6ad3b7c689b3ba5daf37e2481b7e2.jpg


I owe you an expensive beer when I'm done!

I'm going to test the superflux leds now with the diode test on my multimeter in case the heat has damaged them.
I also found an issue in the RH Lemec board earlier.

Turning Encoder 4 lights up the LEDs in the 3 switches below it. I'll post more detail on that later.

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4 hours ago, Smithy said:

I thought IC5 - the 74HC165 was the culprit as some pins were bent so I de-soldered it.

Unfortunately I broke pin 13 / pin C clean off  while trying to straighten it. The issue with the Superflux LEDs staying on when they shouldn't be existed before this btw!
 

image.thumb.png.e78a9af58995eeb968e3c1f144562649.png

I re-soldered the chip again hoping that it was unused, but now Encoder 6 is unresponsive when turning it clockwise / counterclockwise.
At least I presume pin 13 is responsible for this encoder, i could be wrong.

No big deal there, I can buy another 74HC165 off ebay and replace it.
 

Andy can you confirm that pin 13 in IC5 is linked to Encoder 6 before I order the replacement SN74HC165?
Thanks!

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12 minutes ago, Smithy said:

I trusted my cutting of the RJ leads and went ahead and de-soldered all the Mattias switches in the Lemec PCB.
Turns out there was a short between the bottom leg of T16 and the unused pad to the right of it!

Thank god for my desoldering station otherwise this would have taken much longer, if i could even do it all with a manual pump!

IMG_20210526_212922.thumb.jpg.82b6ad3b7c689b3ba5daf37e2481b7e2.jpg


I owe you an expensive beer when I'm done!

I'm going to test the superflux leds now with the diode test on my multimeter in case the heat has damaged them.
I also found an issue in the RH Lemec board earlier.

Turning Encoder 4 lights up the LEDs in the 3 switches below it. I'll post more detail on that later.

Clean work, you're doing great! That is a via that brings the SR signal to the transistor. 

 

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10 minutes ago, Smithy said:

Andy can you confirm that pin 13 in IC5 is linked to Encoder 6 before I order the replacement SN74HC165?
Thanks!

That's right! Not sure exactly what your issue is here, but if you've narrowed it down to pin 13, IC5, you could bodge wire it to pin 3 on J5? Pin 1 of the connector has a square pad.

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3 minutes ago, latigid on said:

That's right! Not sure exactly what your issue is here, but if you've narrowed it down to pin 13, IC5, you could bodge wire it to pin 3 on J5? Pin 1 of the connector has a square pad.

I mentioned it early that some pins were bent on that IC and I desoldered it and tried to straighten them but snapped that pin clean off the IC!
So it will have to be replaced as the copper sticking out of the IC absolutely tiny and I doubt i can bridge it.

 

Edited by Smithy
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So the issue with the LeMEC RH I'm having is that when I turn ENCSW4 clockwise or anti-clockwise, the 2 superflux LEDs and MEC switch SW20 light up directly below when turning that encoder. As soon as i stop turning the encoder the LEDs go off . If i keep it in between the  detents the leds stay on. 
I think keypresses are being registered in MIOS studio also.
Any ideas where to check on the bottom side of the PCB or the far left hand side of the top PCB before I go de-soldering Mattias switches again?
Here are some pics:


IMG_20210528_150848.thumb.jpg.903128cff8a10e9de0417263e5c8c456.jpg

 

IMG_20210528_151036.thumb.jpg.e65a2089b67f59efd2f6d951bda663ea.jpg



I must point out that I lifted the top pad for R13 so ended up soldering the resistor lead to the trace directly I believe.
See pic below:

IMG_20210528_150848.jpg.1967d23504e0d760ac0b05047343cfb4.jpg
 

I'm getting continuity between that leg of R13 and pin 3 aka QD output of IC4 - SN74HC595.
But i presume thats okay? Just thought it was worth mentioning.


IMG_20210528_1508482.jpg.d4f3c641fa539b8d12d837552194594c.jpg
 

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What output do you get from MIOS Studio with "set debug on"? The encoders are directly connected to 165 inputs, so IC4 is not involved here. 

Looks like there are a lot of blobs around IC3?

Encoder pins connect to Plate J1, pins 8 and 9, if that helps. The encoder shouldn't hit anything below it, but you could try to slip a piece of card in between the boards to rule out unintentional short circuits.

R13 does go to pin 3 of that IC. But make sure that it doesn't connect anywhere else.

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I get quite a lot with one single turn of the encoder (from one detent to the next detent - clockwise in this example.)
 

[196444.183] MBNG_MATRIX_NotifyToggle(1, 20, 0)
[196444.183] MBNG_DIN_NotifyToggle(2020, 0)
[196444.184] [EVENT] id=BUTTON:2020 hw_id=BUTTON:2020 bank=0 fwd_id=LED:2024 type=NoteOn value=0 label=
[196444.185] MBNG_DOUT_NotifyReceivedValue(2024, 127)
[196444.186] MBNG_MATRIX_DOUT_NotifyReceivedValue(2, 24, 127)
[196444.188] MBNG_MATRIX_NotifyToggle(1, 36, 0)
[196444.189] MBNG_DIN_NotifyToggle(2036, 0)
[196444.189] No event assigned to BUTTON hw_id=2036
[196444.192] MBNG_MATRIX_NotifyToggle(1, 52, 0)
[196444.193] MBNG_DIN_NotifyToggle(2052, 0)
[196444.193] No event assigned to BUTTON hw_id=2052
[196444.196] MBNG_MATRIX_NotifyToggle(1, 4, 0)
[196444.196] MBNG_DIN_NotifyToggle(2004, 0)
[196444.197] [EVENT] id=BUTTON:2004 hw_id=BUTTON:2004 bank=0 fwd_id=LED:2015 type=NoteOn value=0 label=
[196444.198] MBNG_DOUT_NotifyReceivedValue(2015, 127)
[196444.199] MBNG_MATRIX_DOUT_NotifyReceivedValue(2, 15, 127)
[196444.201] MBNG_MATRIX_NotifyToggle(1, 28, 0)
[196444.201] MBNG_DIN_NotifyToggle(2028, 0)
[196444.202] [EVENT] id=BUTTON:2028 hw_id=BUTTON:2028 bank=0 fwd_id=LED:2031 type=NoteOn value=0 label=
[196444.203] MBNG_DOUT_NotifyReceivedValue(2031, 127)
[196444.204] MBNG_MATRIX_DOUT_NotifyReceivedValue(2, 31, 127)
[196444.206] MBNG_MATRIX_NotifyToggle(1, 44, 0)
[196444.207] MBNG_DIN_NotifyToggle(2044, 0)
[196444.207] No event assigned to BUTTON hw_id=2044
[196444.210] MBNG_MATRIX_NotifyToggle(1, 60, 0)
[196444.210] MBNG_DIN_NotifyToggle(2060, 0)
[196444.211] No event assigned to BUTTON hw_id=2060
[196444.214] MBNG_MATRIX_NotifyToggle(1, 12, 0)
[196444.214] MBNG_DIN_NotifyToggle(2012, 0)
[196444.214] [EVENT] id=BUTTON:2012 hw_id=BUTTON:2012 bank=0 fwd_id=LED:2016 type=NoteOn value=0 label=
[196444.215] MBNG_DOUT_NotifyReceivedValue(2016, 127)
[196444.216] MBNG_MATRIX_DOUT_NotifyReceivedValue(2, 16, 127)
[196444.244] MBNG_ENC_NotifyChange(12, 1)
[196444.245] [EVENT] id=ENC:12 hw_id=ENC:12 bank=0 fwd_id=DISABLED:0 type=CC value=2 label=
[196444.270] MBNG_MATRIX_NotifyToggle(1, 60, 1)
[196444.270] MBNG_DIN_NotifyToggle(2060, 1)
[196444.271] No event assigned to BUTTON hw_id=2060
[196444.274] MBNG_MATRIX_NotifyToggle(1, 12, 1)
[196444.274] MBNG_DIN_NotifyToggle(2012, 1)
[196444.276] [EVENT] id=BUTTON:2012 hw_id=BUTTON:2012 bank=0 fwd_id=LED:2016 type=NoteOn value=127 label=
[196444.276] MBNG_DOUT_NotifyReceivedValue(2016, 0)
[196444.277] MBNG_MATRIX_DOUT_NotifyReceivedValue(2, 16, 0)
[196444.279] MBNG_MATRIX_NotifyToggle(1, 28, 1)
[196444.279] MBNG_DIN_NotifyToggle(2028, 1)
[196444.281] [EVENT] id=BUTTON:2028 hw_id=BUTTON:2028 bank=0 fwd_id=LED:2031 type=NoteOn value=127 label=
[196444.281] MBNG_DOUT_NotifyReceivedValue(2031, 0)
[196444.282] MBNG_MATRIX_DOUT_NotifyReceivedValue(2, 31, 0)
[196444.283] MBNG_MATRIX_NotifyToggle(1, 44, 1)
[196444.284] MBNG_DIN_NotifyToggle(2044, 1)
[196444.284] No event assigned to BUTTON hw_id=2044
[196444.288] MBNG_MATRIX_NotifyToggle(1, 4, 1)
[196444.288] MBNG_DIN_NotifyToggle(2004, 1)
[196444.289] [EVENT] id=BUTTON:2004 hw_id=BUTTON:2004 bank=0 fwd_id=LED:2015 type=NoteOn value=127 label=
[196444.290] MBNG_DOUT_NotifyReceivedValue(2015, 0)
[196444.291] MBNG_MATRIX_DOUT_NotifyReceivedValue(2, 15, 0)
[196444.293] MBNG_MATRIX_NotifyToggle(1, 20, 1)
[196444.293] MBNG_DIN_NotifyToggle(2020, 1)
[196444.294] [EVENT] id=BUTTON:2020 hw_id=BUTTON:2020 bank=0 fwd_id=LED:2024 type=NoteOn value=127 label=
[196444.294] MBNG_DOUT_NotifyReceivedValue(2024, 0)
[196444.296] MBNG_MATRIX_DOUT_NotifyReceivedValue(2, 24, 0)
[196444.297] MBNG_MATRIX_NotifyToggle(1, 36, 1)
[196444.298] MBNG_DIN_NotifyToggle(2036, 1)
[196444.298] No event assigned to BUTTON hw_id=2036
[196444.301] MBNG_MATRIX_NotifyToggle(1, 52, 1)
[196444.301] MBNG_DIN_NotifyToggle(2052, 1)
[196444.302] No event assigned to BUTTON hw_id=2052

 

The blobs around IC is the reflection of flux against the light, the light makes it look like solder.

Its looking like I'll need to desolder the Mattias switches and inspect the top side.

I'll wait til you've looked at the debug messages.

Thanks again Andy.


 

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Not easy to debug sorry...

Basically there is no reason that you should get matrix DIN toggle events when rotating an encoder. There might be some sort of unintentional short between the boards (e.g. from a diode and you push the encoder button?).

IC3 is the shift register responsible for the input side of the matrix, so maybe run the hot air around there or consider replacing that chip? The associated pull up/RN is right next to it

 

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10 hours ago, latigid on said:

Not easy to debug sorry...

Basically there is no reason that you should get matrix DIN toggle events when rotating an encoder. There might be some sort of unintentional short between the boards (e.g. from a diode and you push the encoder button?).

IC3 is the shift register responsible for the input side of the matrix, so maybe run the hot air around there or consider replacing that chip? The associated pull up/RN is right next to it

Pushing the Encoder button on ENSW4 behaves as it should, no extra inputs or anything.

I tried reflowing the IC3 pins with hot air but no luck.
I also desoldered the Mattias switches and took pics of the boards:

Le MEC RH 1.3R top side:
IMG_20210529_164322.thumb.jpg.04a4c0f164db06aa24c3ec38f3fdd11b.jpg
 

ENC Plate 1.0 Bottom side:

IMG_20210529_164341.thumb.jpg.02ff80ac2012aaa4ba5ea33ea1df3504.jpg

 

I'm stumped! Going to order a replacement for IC3 anyways.

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Been looking for shorts while waiting for the 165 ICs to arrive and still can't find anything.
However I decided to temporarily add arduino headers to J-1 to 3 to see if something on the ENC Plate PCB was shorting out something on the Le MEC RH PCB.

Basically the PCBs would be further apart. No such luck there, i'm beginning to think the short is somewhere on the Le MEC RH PCB.

IMG_20210601_224306.thumb.jpg.cbe430e18897ad8af251b0b508674119.jpg

 

IMG_20210601_224205.thumb.jpg.2ae78966b4759d14a9ec56c2e15dee83.jpg

 



I've been checking the small the tiny vias for shorts also but no luck there.
Its driving me round the bend but I'll persist.
I'll update the thread when the 165s arrive and I replace them.

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Just to ask the obvious: are your resistor networks soldered on the right way?

As you have a working lemec_L board, you can probe around for voltages and see where things differ.

The parts that drive the fourth column of LEDs are:

Matrix column RJ4/ RJ8, T15/16 (front side), R24/R25, IC4 pins 1/15.

If the rest of the LEDs in the rows work, then there is no issue with the sink sides of the matrix.
 

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40 minutes ago, latigid on said:

Just to ask the obvious: are your resistor networks soldered on the right way?

As you have a working lemec_L board, you can probe around for voltages and see where things differ.

The parts that drive the fourth column of LEDs are:

Matrix column RJ4/ RJ8, T15/16 (front side), R24/R25, IC4 pins 1/15.

If the rest of the LEDs in the rows work, then there is no issue with the sink sides of the matrix.
 

 

The resistor networks are definitely soldered correctly:

 

IMG_20210601_234116.thumb.jpg.b77bf088ac5da86cbe28c78276a8e6e8.jpgIMG_20210601_234121.thumb.jpg.f0fa23195b7d3589369a5b45436c8282.jpgIMG_20210601_234128.thumb.jpg.af82331bb297f1a31d47d860c47bec4c.jpg

 

Any suggestions for a noob on how to read voltages in the appropriate places without frying the boards? :P

I reflowed all points you mentioned but no luck.

Can't thank you enough for the help.

Edited by Smithy
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4 hours ago, Smithy said:

Any suggestions for a noob on how to read voltages in the appropriate places without frying the boards? :P

Find a spot to clip your 0V lead e.g. the middle pin of the slide switch on the USB board, or solder a wire to the middle pin of the power headers there. Then just go through point to point, measure on the chips, the RJs etc.

BTW, does fluxtest.NGR run properly? 

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10 hours ago, latigid on said:

Find a spot to clip your 0V lead e.g. the middle pin of the slide switch on the USB board, or solder a wire to the middle pin of the power headers there. Then just go through point to point, measure on the chips, the RJs etc.

BTW, does fluxtest.NGR run properly? 

Fluxtest ran fine I'm pretty sure when I had the superflux CC and Mattias switches soldered.

Only interesting thing I've spotted so far is that R24 and R25 seem to be inverted on the Le MEC RH board.

I.E. I'm measuring GND on the opposite side compared to the resistors on the Le MEC 1.0 pcb. But maybe the orientation is just flipped between Boards?

All the diodes are in the correct orientation also.

Edited by Smithy
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