Just something useful here that I thought was well worth posting at this stage. As some of you know, I've had a few issues with my 1FZ. My plan this morning was to look at the clocks on the MVS, in particular the master clock and clocks output from the NEO-D0 and LSPC-A2. Before I did this something caught my eye whilst checking the crystal and the associated caps - the crystal on many MV1FZ boards does NOT have the can grounded. There's a strap over it, but it was 1mm clear of the can all around. A quick check on my multimeter and indeed the can was floating. I've soldered the strap onto the can (note that this can sometimes damage crystals if too much heat is applied), and the net result is I've gone from having loads of CRC problems to litterally none (I say litterally because I've tested the whole day and only managed to get 1 single CRC issue with KoF2003 and this I believe is due to the current test firmware I am on).
But the difference in behaviour is like night and day, and I've compared to 3 other MV1FZ boards and NONE of them have the can grounded (2 had a strap over not making a connection), one had an LC type crystal. One of them was making a connection but was just glued onto the strap, the connection was not very good at all. So it's well worth checking your crystal can is grounded. This won't cause a problem for everyone, it's all about noise in the area, where the crystal is located, perhaps the quality of the crystal and numerous other factors including ambient temperature and humidity - I know this because my CRC behaviour seemed to follow a pattern related to room temperature and humidity and this was driving me nuts!!!
I am curious to understand the difference in quality / behaviour of different crystal types if anyone knows? One of my 1FZ boards has a low profile type crystal the others have the larger elongated can. My guess is they are going to be the same but just in different packages. But the low profile one didn't have a strap and had no way to connect it to ground unless you soldered a wire etc.
Just to re-itterate, if your can is floating you might not have a problem, but if you have a problem with CRCs or other weird behaviour, check that crystal!