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need help: crashing display, total odd letters, can´t save kits (SOLVED )
hello,
i built my LXR 2-3 days ago. the unit has a huge problem.
i run 7,5V/9V PSU which has only 500mAH
first, i thought the crashing display could be because of the soldering of the "stiftleiste"
now it looks very much like software problem.
i had several times crashes when pressing same button,
for example FM in voice mode
i also had several times total crashes of the unit, not only display.
Now, usually the display is crashing after a very few minutes, today sometimes after 10-20 seconds.
The LXR is usually then still working, i just get strange letters in the display.
looks sometimes like russian ( ok, not exactly real) bur has also japanese letters ( real)
crashing, crashing, crashing, since 2-3 days.
i then have to unplug PSU and replug.
....also never could manage to save a kit alone, never get confirmation. on pattern save i do
need help !!!
further info:
one pot was first not running, i resoldered.
now i would say the build is otherwise ok.
can´t see any other problems.
the ones i have look to me like software problmes and bugs, so ...?
Sound is cool, in fact HUGE, would like to move into real use
( can´t read preview of my post)
i built my LXR 2-3 days ago. the unit has a huge problem.
i run 7,5V/9V PSU which has only 500mAH
first, i thought the crashing display could be because of the soldering of the "stiftleiste"
now it looks very much like software problem.
i had several times crashes when pressing same button,
for example FM in voice mode
i also had several times total crashes of the unit, not only display.
Now, usually the display is crashing after a very few minutes, today sometimes after 10-20 seconds.
The LXR is usually then still working, i just get strange letters in the display.
looks sometimes like russian ( ok, not exactly real) bur has also japanese letters ( real)
crashing, crashing, crashing, since 2-3 days.
i then have to unplug PSU and replug.
....also never could manage to save a kit alone, never get confirmation. on pattern save i do
need help !!!
further info:
one pot was first not running, i resoldered.
now i would say the build is otherwise ok.
can´t see any other problems.
the ones i have look to me like software problmes and bugs, so ...?
Sound is cool, in fact HUGE, would like to move into real use
( can´t read preview of my post)
Comments
have you tried re-installing the firmware?
just put the firmware.bin file on the sd card and hold down the encoder while powering up.
then you should see the bootloader.
after a very few seconds crash of the display, empty.
touched poti 1 with a little press down by coincidence, got back some letters but fucked up.
reboot
unit worked now for several minutes. i programmed away.....
pressed open HH, crash. .....again fucked up lettering.
the unit is then allways still working, but getting complete hungups sometimes later.
ok, i pressed buttons to see if i get back the proper display. Never worked so far.
now, i pressed Save, immediately i got a "running display"
= a row of letters, throut the display-left to right, running fast.
pressing "voice" turns into full empty display,
pressing "perf" gives some letters,
"step" gives full empty display
...at the moment i can repeat the above one, allways as discribed per button.
i can press play, sequence plays, and i can stop.
no hungup here at the moment.
often got play hungup when i pressed "save"
so all in all, there is somehow a repeatable behave.
to me it isn´t looking as i would have bad solderpoints.
the unsecure point for me here is the soldering of the pins to which the display is connected
..........and not checkable by eye.
but again, it looks all like software misbehave.
remember, as mentioned first, i got the wipe out now by pressing open HH, wide away from the display
the other thing:
i have lots of problems with fetch ("werte abholen")
now after reinstalling the firmware its even worser it seems.
i had to turn to full CW, full CCW, full CW sometimes even again to full CCW to beeing able to alter values.
also still can´t save Sounds
something`s wrong............
much thanks for help and caring !
(the unit was running while typing)
i can change mode, the last word is shown, ...as is per mode
the LXR sounds so great ! ......lol
some hi-res pictures of your board might help to see some solder joints.
at the moment i have too little data to give a propper diagnosis as to why your menus missbehave.
To take some parts out of the problem, could you remove the mainboard?
The menu will work without the mainboard. you just won't be able to run the sequencer or set/remove steps.
This will take out all the UART communication to and from the mainboard out of the error equation.
First we have to find out why the user interface makes problems
also for now remove the SD card.
garbled characters on the screen indicate almost every time a reboot of the AVR.
tripple check soldering of the AVR socket and the capacitors around it. also check if the chip is sitting thight in its socket.
So whenever you press the open hh button you have the fuckup?
Maybe the button is shorting out something?
Here I would check the orientation and the soldering for U12 and RR9. Also check the soldering on the button.
but since other buttons make problems as well it could be a general problem in the digital input stage.
- the 16 sequencer buttons make no problems? those are the first 2 165er ICs (U2, U5) directly connected to the avr.
- Next is U6 which controls the 8 select buttons (osc,filter, fm, mix etc). these are workin now, too?
- then it's U12 (7 voice + copy button)
- and U10 ( start, stop, rec, shift, voice, perf, step save/load)
can you point the problems starting at any point in this chain? first button/ic group that makes problems?
Is the machine running stable if you don't touch it, or will it reboot all by itself?
If you still have problems try removing all the 595er ICs for the LEDs.
Then it could be a good idea to remove all 165er ICs as well and start by inserting then one after another and see if the trouble starts after inserting one of them (U2,U5,U6,U12,U10)
first:
i built me some 150 modules for my modular during late 2006 and 2010,
i never had any weak solderpoints when debugging modules.
tough i still have a whole lots of modules to debug, lol
i use good weller solderstation and especially a very good solder ...one with silver.
i`m good at home with this equipment, and especially the solder i use makes a difference.
Not saying i could not have bad solder joints. in fact i had one on the LXR on a pot.
I check carefully after soldering a portion with a magnifier lamp.
....i´m not a fan of resoldering ICs etc. just by chance.
I fear it can damage more iof not donne exactly by plan.
so i wait here for now to resolder something.
the thing with the HH button was an example that just happened.
its not that i could say, ok, this and this button is faulty.
It was more to say: there is a connection between misbehave of display and hitting a button.
so far i´d say i never had problmes with the 16 step input buttons,
definitly most problems with the mode buttons,
sometimes start etc,
sometimes the 8 select buttons.
now after taking the mainboard off, i had following:
fisrt "session" i had immediately a crash,
second: pressed buttons for around 5 minutes, no crash, then 7 minutes not pressing anything, first button press: crash.
i had several sessions going without pressing anything, ...between 10 miniutes and 50min or so, allways after first button press, or possibly sometimes a few presses: crash
so there is a data input problem
problems with pots in fletch mode were not related with bad soldering on pots,
in non fletch mode the pots behave good
No, definitly the machine is not running stable when touching nothing.
the last days inc. today there were sessions that looked as the machine runs more stable when keep pressing buttons, sometimes it looked......well especially after breaks...then anyway ! that pressing buttons causes mostly the problems.
i gonna recheck now the ICs.
ahhh wait, start/stop is on U10 as mode buttons are ?
i start here. that was definitly the most obvious problem with buttons,
select buttons less so
much thanks for the help, much appreciated !
let me know if you want to see more, or better quality
ohh edit: i´ve not cleaned the board.......man, not shure what held me back
i have a desoldering iron coming ( hakko 808)( so far i was absolutely weak on desoldering )
but to me its just not just looking like bad soldering on display.
..........not understanding electronics, especially digital that good, ...if any
two things to know:
1. could be just alone the LCD connections ?
can we at this point say, it could be that we can exloude anything else and would have exactly same problem
2. If not, could you sell me just another batch of the Ics in question ? thats my next thought
ofcourse can i fail , ...and yeah you are right !
my comment on "it was not the soldering" was meant mainly to U10,
and i meant that it just doesn´t make any sense to resolder everything !
........i have not a solderproblem that is visible for me by eye.......if there is one......its a hard to find one.
my point is to get step by step closer to the points where the failure is,
The Idea with the ICs was to get one equation out of play, this or the other way.
.........i´m not good in debugging, any help is a good one
ok, the dasiychain thing is intereresting. ........I resoldered just U10
question is now how heat sensitiv are these ICs ? can i really resolder all those without removing them ?
i´m quite bad on taking ICs out.
next thing is i have no wrist-Ground-guard, or how its called.........
thanks ! any help welcome
for me, its about 450$ to be or not to be
my ICs have sockets ofcourse !
and yes, ofcourse gets the IC quite a bit of heat when you resolder the socket.
no, i don´t know how much ! no, i don´t know if it could be too much for the IC.
303° ? really ?......i´m on 360°
......no i do not weigh any of my words on three different golden balances just to keep any weak point in my wording off just to be 100% secure that "that guy with just too much iNet time" won´t bitch around.
so stop here now please ! give Julian a chance to chime in. thanks
DON'T PANIK!
I'm sure we will get this sorted out and you won't end up with a broken kit and lost money!
It's good to know that you have soledring experience.
- I'm 99.99% sure the display is not the problem.
- ICs are heat sensitive to some degree but unless you really toast them you should be good.
the 74HC165 for example has a maximum STORAGE temperature of up to 150°C. so as long as you can still touch the IC it won't take damage.
- have you checked the soldering around the 7805?
to be honest I'm a bit puzzled by those rebooting bugs some people have reported. most of them got sorted out, but not in a manner that I could really explain why the AVR rebootet in the first place. I'm nearly at the point where I'm eager to get my hands on one of the rebooting units to find out why exactly the AVR is rebooting. Unless something is shorted to GND I would expect that faulty shift registers cause some of the UI elements to behave strangely, but not a rebooting processor.
In the end, the daisy chained shift register ICs just provide a binary value for the buttons that is read by the AVR and it sets the buttons memory location accordingly. From the software side there is not much that should go wrong with problems on those registers unless the buttons short something out.
I think it is more likely that the mechanical stress on the PCB while pushing down a button is causing the unit to reboot.
I can think of 2 legitimate reasons for a reboot of the AVR.
1.) short circuit or power drop out due to a flaky soldering joint and mechanical stress from the button presses or a resistor network with the wrong orientation.
2.) broken firmware installation on the avr.
- could you check the soldering of the SD card slot pins on the mainboard? maybe poke the a little bit with a needle to see if they are loose if you cant firgure out by looking.
Also check the 4050 IC on the front. Maybe there is a loose contact on the SD card that causes read errors when installing the firmware?
are all the ICs all seated correctly in the sockets? you have to push them down more firmly than in the cheap IC sockets.
regarding re-soldering of the ICs.
I would start by resoldering the AVR and the PSU section.
The display problem remains.
what i did:
checked carefully all Resistor Networks for orientation. all fine !
resoldered all resistor networks
checked all Ics for orientation, all fine !
resoldered all IC ( sockets ofcourse) ( many of them a third time)
again tryed to press in the ICs more into socket carefullöy (third tiem)
resoldered AVR
resoldered PSU part
resoldered the display ( some pins were not looking perfect)
all resoldering donne carefully under the magnifierglass-lamp
i took another PSU (Doepfer) with higher mAH rating 800mAH or so
Problem remains the same !
i can press buttons for 2 minutes or so, no problem, when i not touch anything for 2-3 minutes
and press buttons again, scrumbled display.
sometimes by not touching anything for a while.
otherwise, the drumunit itself works ! ( ok, not checked again )
after resoldering today, i only checked without mainboard.
yesterday with and without.
display problems allways there.
much much thanks for the help so far !!!
i´l have a look here and will try some more reloads of the firmware
i was able to play something like 10 minutes.
programming away, saving pattern with some hickups.....to get "enter" donne was a hard task.....anyway
then 2-3 minutes without touching anything as a test, next press of a button: scrumbled display again
sidenote:
my doepfer PSU which is rated 9V 800mAH,
but i measured 12V or so.....
the 5V regulator becomes really hot.
i can touch it for 10 seconds or even less
but as PSU can be a problem.......not shure if thats really that good to continue with the doepfer PSU.
all others are rated 500mAh
anyway, my LXR was never running as long without crashing with the new firmware,
still not as needed.
i try tomorrow to load the .bin again and see.....
next step is then indeed to try new "IC" as i allready mentioned...bevore resoldering, lol and fcd72 mentions too
thanks !
2 other users had problems with incomplete menu pages, one of these got solved today with a new AVR.
I'm out of ideas what else it could be. Flashing the firmware should not be something you have to do over and over again. On a working unit you do it once and that is enough.
sorry for the trouble you went through so far!
Julian, no need to excuse, really.
You deliver a great support here. This is much appreciated !!
>>I will send you a new AVR and a new quartz on monday. <<
i´l send you after this post my adress in case you don´t remember in respond to your last mail from the shop
( shipping notification)
and please, let me pay for the parts and shipping.
who knows, at this moment its not cleared up if its really wrong beaving parts, lol
thanks to you and fcd72 !
chnaged the quartz and the AVR.
problem remains....strangly, in fact it was still worser now.
unit is without encloser, but was allready at my last tests....
got total black display,
first i got two times a black display when moving the LXR
(it sits on a MPC4k with a manual on top of the 4k, so its a bit slippery and not even ,
so i had to move the LXR back)
so, two times failure, defintitly caused by the move/vibration.
........makes me definitly think that it is the display connection
( not thinking the new AVR made someting worser, ...might be coninsidence )
further tests, i got balck displöay also while not touching anything, just waiting.
similar as with old AVR, just that i then got not a total black, just scrumbled letters.
i could bring back display to live sometimes, getting the the scrumbled letters.
.....not the first two bail outs.
gonna desolder the display.
got me a hakko808 desolderiron in the meantime. US
but gave a way my US-PSU converter to a friend
(wanted to get replacement converters from germany, ...would take time )
possibly i can take the one in my modular out of the rack....otherwise it might take some weeks
ok, again: have to desolder the display, then we can check further.
so far my opinion
MUCH much thanks @ Julian for the quartz and AVR !