Gold .. Anybody know what the 'gold' metal used on connectors is, okay some board pads and expensive audio may be gold, but PCB connector pin headers, I assume something else.…Rhodium ? To make a short story long .. Having chased many 'stupid' faults during my service engineer career I came across a couple that were due to that connector plating … ( this is one such ) back in the 1980's A savings bank had a batch of new (386) PC's for their front counters , the user requested a longer vga cable for a small 10” colour monitor. 'Sales' had some made and fitted ( an internal 10 pin connector) .. after a few months at one or two sites the customer complained monitor had reverted to monochrome ! Engineer swaps out monitor … Oh new monitor cable too short... so swaps old cable back... good repair all working again ...! No a month or so later monitor is mono again.. also customer is having same problem at more sites (sometimes a pink display )..after several monitor swaps .. customer was a 'bit' annoyed.. I was tasked to find cause.. as rework could not get a PC / Monitor setup to show the fault. Okay. The new long cable had cheap 'tin' tags attached to the monitors 'gold' pins . And with time and some sweaty hands of an bench engineer the two metals reacted and caused some nasty black coating...the new PC's had a new type of Cirrus vga chip that could tell if it was connected to a colour or mono monitor and the correct driver then installed . The higher resistance caused by the connector contamination , caused it to select the wrong one.. I have not learned …. I regularly use 'tin' tags on 'gold' pins .