Thanks Kaerf -
Bridge all 4 (i.e. SJ16,SJ17,SJ18,SJ54)?
Bridging all solder jumpers can fix the SPI chain by taking
out the bad ASIC. But when the ASIC still has functional
output drivers (meaning: the ASIC is not hashing, but the
outputs still drive a logic level on there pins) this shorting
of the solder pads won't help much. The ASIC has to be
removed from the chain completely then. To do that, cut
the traces at two points with a small snap-off knife and
apply some heat with the tip of a soldering iron. The glue
between the copper and the board will soften and the trace
can be removed easily, without doing any damage to the
board. You even hardly see it when done with care.
Shorting the jumpers also has a little trick. Applying solder
in one go can be tricky. Just apply solder to one pad and
let it cool down. Then apply solder to the other pad and let
it cool too. Repeat a few times until a small lump has 'grown'
on each pad. Then in one swift motion connect both lumps
with some more solder.
intron