preenfm Forum
PreenFM => preenfm2 and preenfm3 => Topic started by: tmk009 on December 11, 2014, 01:32:43 AM
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I just finished soldering of the kit and cannot turn it on. Jumper 1 + 2 are set. The orientation of 7805 is as it should be. But the preemfm doesn't turn on and 7805 it's getting extremely hot.
To be honest, I'm lost.
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Check all your ICs direction (especially the op amp).
Could you post picture of the back side of your pfm2 ?
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there you go!
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Better resolution please ;)
640x480 is not enough. I don't even see if JMP3 is set or not... (It should not).
And a picture of the other side without the OLED screen.
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yeah i had no converter on my phone, now its ~ 800kb.
the other picture i will take today evening when i'm back at home.
[attachment deleted by admin]
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What power supply do you use ?
Have you tried powering it with USB only ?
I'll add tonight some 5V/GND/3.3V points to check.
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I tried both: with USB (computer + usb-wallwart) nothing happens.
With a 7,5 or 9v wall wart power supply the 7805 is getting hot quickly, but still stays off.
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I don't see diode D2 & D3 on the pictures near the 7805.
Directions are OK ?
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yes, according to the picture:
D2: silver ring to south
D3: silver ring to west
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and here the photos
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next
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another one
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and the last one.
[attachment deleted by admin]
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I don't see any obvious problem with your pictures.
You can clean up a little the PCB ;) Most of the time, the yellow things on the PCB can be removed easily.
You could start checking the following values
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When you say the preenfm2 does not turn on ?
What do you mean ? is the screen black or all yellow ?
You tried with a USB stick with the "/pfm2/" directory on it, right ?
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yes, i tried it with different usb sticks, all FAT formatted and different sizes/manufacturers.
When i put the USB Cable into a Computer, it says: "USB deactivated, the device is taking too much power blablabla..." and the preenfm is not turning on.
When i put in a regular 7,5V or 9V cable (with and without Jumper 2), the 7805 ist getting hot but still not turning on.
Not turning on means no signal of life at all: Display stays black. No LED is blinking, the USB stick led (if available, i tried different) is not blinking, nothing.
MEH
Any idea?
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When i put the USB Cable into a Computer, it says: "USB deactivated, the device is taking too much power blablabla..." and the preenfm is not turning on.
When i put in a regular 7,5V or 9V cable (with and without Jumper 2), the 7805 ist getting hot but still not turning on.
...
Any idea?
Seems like you have a shortcut somewhere that make the preenfm2 consuming a lot of current.
You could try first to clean a little the PCB from the yellow materiel that appear on the PCB when soldering. You can get rid of most of it with a small screwdriver, it's hard enough to crack and be removed.
Try to remove the ICs and OLED and check with "0 ohm beeping mode" multimeter for some shortcut between adjacent points.
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Ok. Looks like a job for this weekend 8)
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Same, I can not see any obvious thing sorry :(
There are a few soldering point that look kinda "weird" though, I would advice you to resolder any point that looks kinda like a ball, I'm sorry I don't have the time now to highlight those on your picture. Unless you're 100% sure of your soldering skills?
The yellow should come from the flux of your solder, mine produces quite a lot as well, it shouldn't be a problem but who knows, maybe it's hiding one!
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Yeah, I'm quite sure about the soldering, but I'll double check it! I just realized Xavier made these checking points for me. Great! I will at first clean it, resolder it, measure shorts with a beeper and then finally check the voltage.
I bet this is something stupid.
Thanks guys, read you in some days.
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I just realized you won't have the 2.5v if the preenfm2 does not boot.
And if there's a shortcut, there's good change everything is 0v.
Good luck
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Found it! It wasn't the pcb - there was a short at one of the display pins. I was too concentrated on the pcb though... Perfect. Let's check it out now! The encoder values are jumping a little, but this is a new problem to solve.
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Found it! It wasn't the pcb - there was a short at one of the display pins. I was too concentrated on the pcb though... Perfect. Let's check it out now! The encoder values are jumping a little, but this is a new problem to solve.
Congrats ! :)
For the encoders, see the very last line of the doc :
http://ixox.fr/preenfm2/build-it/the-pcb-r5/
;)
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Just want to let you know everything is fine now 8)
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Just want to let you know everything is fine now 8)
Great... thanks for the update. :)