After a long day, there'll be another one (2011-12-21)


EvilDragon

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Of course, the question for today is: How did it work? Did you get working boards? Is everything okay?


Well, we got halfway through it, it's not looking bad :)


There was one problem with the stencil (the holes for the solder paste were too big for the BGAs), so usually, this would've meant: Okay, time to go home until a new stencil will be there.


Well, the new stencil will be there tomorrow morning, but we wanted to try to get a PCB working anyways, so we tried one PCB where the BGA pads had NO solder paste.


This COULD work out - or not.


It seems it worked half.


There are three BGAs on the board (BGAs are the chips with VERY small solder balls that are below it), the most complex one is the OMAP, the second complex one is one that does all the power management.


We populated a PCB and tried to boot it up - and, yay! It booted! U-Boot was clearly seen via serial out and I could access my testing card in Slot 1 via my netbook.


However - I didn't see any picture. Backlight came on, but no picture.


Damn.


So it was time to get in contact with MWeston, who quickly replied to me what I could measure where.


It seems the LCD doesn't get power.


Hmm.


Okay, time to do the remaining tests...


USB... working.


SD Slot 1... working.


SD Slot 2... working (after we found one pin was not soldered properly)


WiFi - no Power.


LCD - no Power.


Audio Amp - no power.


Battery charging - nope, didn't recognize that I connected an AC Adaptor.


Well - there were two solutions:


Either A LOT of stuff is broken on the PCB (but then again, it could only be a lot of missing parts...) OR something with the power management is not working, which would explain why so many parts didn't get powered up.


As mentioned: One BGA does the power management - and the way we tried to get it working was a "could work - or not"-thing.


So yeah, most probably that power chip. It handles every other current than the main 5V one. And exactly these parts are not properly working.


Tomorrow at 8:30am, we'll continue with out adventure. We'll have the proper stencil for that, so population should be fine this time.


In case something still doesn't work, we'll go to do some X-Ray tests tomorrow. This would reveal any missing traces or similar.


Even if the boards work fine, Global Components will do some X-Ray to see if the machines can be further optimized for some parts to minimize the failure rate.


I'm pretty happy that the machine booted up.


Firstly, it's the first time Global Components EVER did a PoP (and it worked on first try), and secondly, debugging would be hard if it didn't even boot.


The GTA04 team had similar issues: 3 out of 3 PCBs they got from their run didn't boot. They managed to get one half working after a day, so for a prototype run, issues like these are normal.


But things are looking good that we'll have fully working PCBs tomorrow, so stay tuned for more updates :)


This means that actual production run will start early February (unless something else goes really wrong), but I'm happy we got something to boot today :)
 
Can you manually override the power management chip with a well placed wire, then test other bits of the PCB? Or is it wayay to complicated a board.
 
If at first you don't succeed ---- try and try again. It will all come together no problem I'm sure !!

No worries, we won't give in here ;)

Can you manually override the power management chip with a well placed wire, then test other bits of the PCB? Or is it wayay to complicated a board.

Way tooo complex - and wouldn't make sense.


Properly populating them tomorrow and doing some X-Ray in case something still doesn't work makes way more sense :)
 
Unofficial short version of this thread:


A: "Captain, we've been hit! Our engine has failed!"


C: "Quick! Do a manual override on the power management chip with a well placed wire, then test other bits of the PCB!"


B: "But Captain - that's way too complex and wouldn't make sense!"


C: "You're right... reroute power from X-Ray system to repair damage!"
 
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Yeeeah! :)


I was really excited when reading the post. And it seems there was just one issue that caused some others. Well, let's hope this appearance do not fool us.

This means that actual production run will start early February (unless something else goes really wrong), but I'm happy we got something to boot today :)

So we'll miss January 16th because of CNY?

Tomorrow at 8:30am, we'll continue with out adventure. We'll have the proper stencil for that, so population should be fine this time.

At this time I will probably try to get a bit more sleep --- on a table. ;)
 
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Yeeeah! :)


I was really excited when reading the post. And it seems there was just one issue that caused some others. Well, let's hope this appearance do not fool us.

Yeah. That's my wish as well :)


I'm very anxious :)

This means that actual production run will start early February (unless something else goes really wrong), but I'm happy we got something to boot today :)
So we'll miss January 16th because of CNY?

Sadly, yes. On the one hand, it makes me sad, I really wanted to catch that one.


On the other hand... I'm currently also moving into a new home, and I got to move all my stuff and clean up the old rooms within the last two January weeks, so this might help that I won't work myself to death ;)
 
Why not keeping the old, working board layout? It reads like they have to do an entire new PCB, I thought only some small parts have to be changed but not the big BGA Chips - these have always worked I guess. :huh:


However, it is funny to read that they even can do X-Ray tests with the PCBs, they really have X-Ray machines for that? ^^
 
Why not keeping the old, working board layout? It reads like they have to do an entire new PCB, I thought only some small parts have to be changed but not the big BGA Chips - these have always worked I guess. :huh:

The BGAs have not changed - why should they have?


It's just a few condensators and similar parts that have changed.


But every new company has to redo everything from scratch.

However, it is funny to read that they even can do X-Ray tests with the PCBs, they really have X-Ray machines for that? ^^

Sure, there's not really any other proper way to test it for BGA or PCB problems.


Try to follow traces without it with an 8-layer board.
 
Bloody Hell, even my wife's getting excited, though that may have something to do with her finishing work 'till the new year, way to go ED.
 
I have one word for this: Unacceptable. Now deal with me.


// Might be joking/drunk. Might.
 
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Way to go Open Pandora team! Glad to hear the boards are working (sorta). Sure the screen and wifi didn't work, but it's only a prototype. These kinds of things are expected to happen, that's why they call it a prototype.


I admire you guys for never giving up on this project :) , and I don't forsee you giving up in the future (or ever)! Keep up the good work, I can't wait to hear how tomorrow pans out. Keep us posted (not that I needed to say that, because you always do :p ).


Long live the pandora!!!!!!
 
Oh, cool, now we're getting updates from the floor? :lol:

Well, if you followed the stalker (or twitter), you also could find updates yesterday as soon as I knew something new :)


Though I connected my netbook to WiFi today, so I can post here as well.
 
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