Re: QMX unboxing and a couple of surprises
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Hello John
The first thing I did was to check off all components against the parts list. There were two knobs in a separate bag and another two in the main packaging, so I¡¯m two knobs up! The knobs all appear to be the same size.
Bonus for you! Kick for my colleagues...??
I then removed the PCBs from their anti static bag and immediately photographed them. The LCD board was broken off from the main board - I¡¯m not sure if that¡¯s to fit them in the bag or whether it got damaged in transit.
That's not how we pack them, we pack them in one piece. Not broken apart. So this must be a transit thing. Nevertheless it's the first time I have heard of this so I think it's not common, and in any case the first thing you are going to do is break the boards apart so it should not matter.??
Looking at the photos I saw that C205 and C210 had broken off the main board. Coincidentally one of them appeared in one of the other photos, and I found them both on the tray.
C210 is a 100nF decoupling capacitor and might not be critical, but C205 (47nF) is on the processor reset line and might be essential.
Neither of these capacitors are critical. I believe the 47nF on the reset line is only required during Flash programming of the bootloader. Once done, it is not a requirement. The other decoupling capacitor as you say, is a prudence (follow all datasheet recommendations on capacitors everywhere) but it should still work without it.?? I¡¯m quite happy to resolder the capacitors but neither of them check out with their correct value (my DVM has a capacitance range, I checked some through hole capacitors to confirm that it was working).
I wouldn't worry about that either. I don't use expensive precision capacitors for the capacitor positions where it is not critical. The expensive capacitors go in the LPFs and BPFs.?? My suspicion is that the capacitors got knocked off by the LCD board in transit, which is why they were in the packaging.
I suspect you are right? Hans, if the boards are supposed to be separated, can I suggest something like a piece of card slipped between the two to prevent the capacitors from being knocked off?
The PCBs aren't supposed to be in two parts...? If I order some replacement capacitors, I¡¯m thinking of substituting 47nF for C210 so I¡¯ve only got to order a couple of the same value.
I would just use the supplied ones. Or not bother...?? Any comments/suggestions gratefully received.
?I'm sorry to hear about the mishaps but I think these are non-critical things, that won't affect anything about the build outcome - so I'd just proceed regardless...
73 Hans G0UPL
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