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Troubleshooting
If your Quark doesn't work after assembly and testing, take a deep breath, get out a beverage to
clear you mind, and start troubleshooting...
Check Your Solder Joints
The very first thing you should do is to check out all of the solder joints under a lighted
magnifier. The most common reason for things not working are solder bridges, i.e. putting too
much solder on the pads and shorting two adjacent pads together. You can also get into
problems by bridging pads with "vias" on the board, the smaller holes that don't have any
components soldered to them. Most of the pads are very small, so it doesn't take much solder
to get a nice "tented" solder joint. If you get a solder bridge, heat it up and use a solder wick or
a vacuum bulb to remove the excess; afterwards, we recommend resoldering the joints. Note:
NEVER use "canned air" or compressed air to "blow away" excess solder. The resulting
splatter will almost always cause more damage than the original solder bridge, and if you get
solder splatter under the baro module there's no easy way to fix it.
Another thing to look out for is "cold" solder joints, they look dull and blobby compared to a
nice shiny "tented" solder joint. If you have a cold solder joint, it won't conduct well; at the
low power that the Quark uses this could easily keep things from working. If you have a cold
solder joint, heat it up and put just a little bit of solder on it, the main idea is to get a little more
flux on the joint. If there's too much solder, use a fine solder wick or (preferably) a vacuum
bulb to remove the excess, then heat it up and resolder the joint.
Finally, it is relatively easy to actually miss a solder joint, especially with the optoisolator since
it has very "stubby" leads. When you solder the pads, don't just melt the solder on top of the
leads... it can get stuck there and actually miss the pads. We've had it happen. Head up the
pads, not the leads, then gently apply the solder until it flows around the leads.
Check Your Component Polarity
Most of the small components aren't polarized, with some notable exceptions (i.e the diode).
The outline of the parts is silk-screened on the board, so you should be able to see readily if
you have a component soldered in backwards, or sideways.
If you inserted a component incorrectly, you will have to carefully unsolder it, clear any solder
residue from the holes, and resolder it. If you find that a component was soldered incorrectly,
you will have to use a vacuum bulb or vacuum desoldering tool to unsolder it. We cannot
stress enough that you need to check the orientation of the parts before you solder them. The
Eggtimer Quark Limited Warranty does not cover damage to a component while attempting to
unsolder it, so make take your time and make sure you get it right before you solder.
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