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geekhack Community => Keyboards => Topic started by: wetto on Sat, 13 July 2013, 18:38:35

Title: Help me analyze this keyboard PCB
Post by: wetto on Sat, 13 July 2013, 18:38:35
Hello guys, I'm trying to make a honest review of the Tt eSports Meka G-Unit (since 99% of the reviews out there are filled with bull****) and after analyzing its external cover (which is made of some low quality plastic), its keycaps (which are complete crap), I came across the most monstrous keyboard PCB I've ever seen.

Since I'm not really an expert when it comes to PCBs, I'd like to know what mistakes/errors can be found on this PCB. I can point some out first.

1. WAY TOO MUCH RESIDUE!
2. Some solder points are way too close to each other.
3. How they connected the PCB to the USB HUB/Connector. It's utter crap.
4. Some solder points lack solder. Others, have way too much.

(http://i.imgur.com/uOcLkxP.jpg)
(http://img14.imageshack.us/img14/8262/wq8j.jpg)


Just FYI, here are some other PCBs I took pics and all look great:

CM Quick Fire Rapid:
http://imageshack.us/a/img577/1105/dsc03031y.jpg

CM Storm Trigger:
http://imageshack.us/a/img811/6683/dsc03649l.jpg
Title: Re: Help me analyze this keyboard PCB
Post by: rootwyrm on Sat, 13 July 2013, 19:06:47
The "residue" you're talking about there is normal cleaning solution. It happens pretty constantly on motherboards.

Controller sub-board joints have very poor reflow, but the method is not wrong. Period.
Overall soldering is very sloppy. The joints wouldn't look anywhere near too close except that the soldering is just abysmally half-assed. Obviously still not too close, if it's working. But it really is sloppy work. I've seen worse.
What does crap solder and crap parts look like? Well, here's a really good example. (http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=335)
(http://www.jonnyguru.com/modules/NDReviews/images/AcePower550/DSCF0008.JPG)
Title: Re: Help me analyze this keyboard PCB
Post by: gnubag on Sat, 13 July 2013, 19:13:50
there is no problem with solder joints being too close to each other aslong as the silkscreen is decent and the solder is not forming a bridge.
Title: Re: Help me analyze this keyboard PCB
Post by: Photoelectric on Sat, 13 July 2013, 19:14:38
I don't see too little solder there anywhere, more like too much in most cases.  Still nothing that would affect functionality, in theory.
Title: Re: Help me analyze this keyboard PCB
Post by: ___q on Sat, 13 July 2013, 19:46:00
Yeah, the leftover flux residue is harmless.

The soldering is overall a bit sloppy, but doesn't look like it should impact durability or anything. I bet the soldering job in a lot of the customs in the classifieds is no better (depending on who built them) ;)
Title: Re: Help me analyze this keyboard PCB
Post by: rootwyrm on Sat, 13 July 2013, 20:12:35
Yeah, the leftover flux residue is harmless.

The soldering is overall a bit sloppy, but doesn't look like it should impact durability or anything. I bet the soldering job in a lot of the customs in the classifieds is no better (depending on who built them) ;)

Yeah, the old stuff would occasionally cause problems because on occasion it was conductive. (Due to dilution.) You know immediately if it's conductive because, yeah, things don't work. It's obviously isn't conductive since, you know, the keyboard works. Really what you're seeing is the leftovers from the bath - which just means the stuff didn't wash off well. Can't use certain solvents any more either, and if you use water you have to collect all the runoff, which makes it that much harder (and more expensive and difficult as well.)
Title: Re: Help me analyze this keyboard PCB
Post by: dorkvader on Sat, 13 July 2013, 20:14:56
I'd say the method of attaching the controller is suspect. I know connectors add a little money to a design, but they work.
Title: Re: Help me analyze this keyboard PCB
Post by: WhiteFireDragon on Sat, 13 July 2013, 20:45:11
Everything you listed aren't exactly problems, but definitely not a good quality.

From the pic, it looks like the daughter board that has all the main controller components, is only attached by bridged solder joints. This is not a robust way to hold the controller on there.