PbF policy China and USA ?

[N_Cook]

Line 6 Spider 3 amp with RoHS and PbF markings all over, date only 2008, no
abusive use/speaker/lead problem. The boards are obviously PbF , white
deposit as though been in a damp shed for 10 years. That is except for the
interboard ribbon soldering. Boards populated and soldered in China with PbF
solder and assembled in USA with leaded-solder or 2 flavours of PbF solder,
one goes white easily and the other stays shiney?
TDA7293 failed , going by burnt off lacquer on the minor trace between
power - supply and signal - supply , then failure in signal half of the amp.
Final failure was sub-ohm connection between +,- and output pin and about 40
ohm to ground. If there had been intermittant contact to a pin due to PBf ,
could that knock out a hybrid? Tugging on dropper Rs etc has not shown any
so-elucidated poor joints on the rest of the board and no PbF part-ring
cracks seen.

 

[N_Cook]

Unlikely joint failure at the pins as they are set in ring-barb hank bushes.
Monolithic, not hybrid, I decided to crack this one open , not much to see
other than smoke staining and strong smell of smoke.

 

[N_Cook]

I reckon it was probably slack h/s clamp. Although not noticably loose on
undoing, there is no permanent deformation of the silipad on this one
(unlike its companion TDA). Clamp is 3:1 ratio cantilever U section steel,
ratio the wrong way and no star washer or equivalent under the retaining
bolt heads