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No LED blinking after soldering, but only strange sings on LCD - [SOLVED]
Hello,
yesterday I finished soldering, but when I want to power it up there was no LED on.
When I powered it a second and a third time suddenly all LED lighted up, a few minutes later I turned the voltage off and on again and the LEDs didnt light anymore. I think this is kind of strange.
Another thing is, when I connect the lxr to my pc via USB, the pc shows me that a "Sonic Potions Midi Device" is connected.
Today I checked all ICs and the solder points but everything seems to be ok, then i soldered the LCD.
The LCD schows me 0.23, this should be the firmware version, and some strange chinese signs.
Soo I need help, because iam out of ideas 
Comments
The frontpanel has nothing to do with USB.
The stateof the LEDs on power up is random untill the AVR starts controlling the shift registers. So this is also correct.
are the resistor arrays in the right orientation? (dots in square)
especcially the 10k networks for the buttons.
I can't see it very good, but the soldering on the mainboard connector looks a little bit sketchy. could you send a close up picture or take a closer look yourself?
but could you post a closeup picture of the mainboard connector soldering?
On the pictures several pins look as if not soldered correctly.
Same goes for the bottom of the front PCB, so we can see the rest of the soldering job.
Maybe the soldering around the AVR, too (quartz area)
The other option needs more work. So I would prefer to see a picture first, maybe its just a cold solder joint
Since there are several things that are not working, I think it would be best to solve them step by step.
- You have no correct LED output
- The display is not working
- maybe the buttons, too
- mainboard seems ok (USB works)
First I would try removing the 165 (buttons) and 595 (LED) ICs and see if the display is working then.
Do not remove them without a tool (even a normal flat head screw driver to level them out from alternating sides is better than only your fingers.)
Do you always have scrambled characters only, or does it show correct text once and then goes to changing scrambles?
they play no role in display functionality and can maybe remove some error sources.
The LCD changes every three seconds between theses scrambled numbers and 0.23
Actually I "beeped" (durchgangsprüfer?) the connection between the pcb and the mainboard they are okay, but I will take some closer pictures in the afternoon
Btw. Thanks for your support
Gesendet von meinem HTC One mini mit Tapatalk 4
The new haven displays don't like a soft reboot at all.
That is If the AVR restarts and the OLED still has power.
This nearly always results in a garbled screen(the display has no reset message:-/ )
So what seems to happen here is that the AVR is constantly rebooting after the first bootscreen.
So it never has the chance to initialize the 595 + 165 shift registers.
It seems you should look around the AVR solder joints.
22pF caps + Quartz, 47nF cap and its neighbouring 10k resistors.
I hope it is not a broken quartz.
I chose a higher quality part this time.
Do you have an oscilloscope or an AVR burner?
I took some pictures of the Mainboard solder joints and and the quarz area.
i just checked the two caps, the 100n is ok but the 22p has actually around 60p. Is this toleranz ok for the function?
have you messured the caps only or in circuit after soldering?
thoser solder joints look all good to me.
tomorrow i will solder a new 22p in, maybe something happens
should I send you a replacement quartz and two 22pF caps to see if that is the problem?
The support here is really amazing and fast
so it's still the same?
- no mainboard attached
- no ICs inserted besides the AVR
- strange signs on the OLED that change every few seconds (AVR probably rebooting)
- is the display working when you start the bootloader?
no need to attached the mainboard or insert an SD card.
If you power up the synth while holding down the encoder the display should show
"Bootloader v1.2"
"SD error"
Do you have a solid PSU connection? Tried another power supply?
Otherwise I'll send you a new AVR since i'm out of ideas here, too!
Without the ICs inserted there is not much left connected to the AVR that could go wrong.
In the end it's just display, pots + encoder
When the bootloader works, then the avr should be ok?
have you tried re-flashing the firmware?
Additionally I make a short test of general functionality after burning the chips.
So at least here in my test unit the avr and the mainboard were producing sound;)
I will now look into the code again to see what are the differences in activated system peripherals between the bootloader and the main programm. What confuses me is that the bootloader is running, but the main software not. this indicates a software problem in the main programm. but for all the other people the main programm is running ok.
So I assume there must be some software bug that triggers on rare hardware conditions... O_o
Just reflashed it and everything works shit
Just as I was building a debugging test firmware version to catch unhandled exceptions
Anyways. glad it works and that it was such a simple thing.
somehow I thought you already tried re-installing the firmware already
now Have fun with your finally working synth! :-D
But now everything works fine and the lxr is an amazing machine
I mailed Julian about this a couple of times but I'm not sure he receives my mail.
My symptoms:
When power is turned on, the screen is filled with blocks
for 3 seconds, then blinks and shows blocks again, then sometimes “23” + filled
blocks, and sometimes flashes of strange characters.
Sometimes all the
leds are turned on (and kept on), sometimes a few leds and sometimes none.
Nothing else happens. The LXT is completely unresponsive.
I’ve gone
through everything meticulously to make sure all the components and ICs are
soldered in the correct place and orientation. I also inspected all the solder
points with a magnifying glass and measured voltage to close to 5 volt. No IC or
component gets hot, except the heat sink, but not so much. I’m using a standard
1 A DC-adapter set to 7.5 v.
Here are two pics of my build, taken before I soldered the display.
So what do you think? In need of a re-flash?
/Björn
To which email address did you send the emails?
Have you tried updating the firmware?
Or does the LXR also not respond in update mode?
To start the firmware update put a SD card with the firmware.bin file in the LXR and hold down the encoder while powering on.
Did you do the test mentioned in the assembly guide (step 20)
was the chaselight working before you attached the display?
I'll have a look at your pics now.