Strange alloy on controller board

[MrLeo]

Hello!

What is the strange alloy the control board is covered with? It is oxidised even on new disks. Why some disks have tinned control board, but other covered with this ugly alloy?

http://fcshop.ru/goodsimages/87000/87200/87279/194693_L.jpg

Thanks!

P.S. More photos of WD boards.

[MrLeo]

So, nobody had such problem?

[Bill_S]

Since there’s been no replies, maybe you should try contacting WD’s Technical Support about this. You can do so either by phone or email.

To Contact WD for Technical Support
http://support.wdc.com/contact/index.asp?lang=en

[fzabkar]

I took the liberty of posting your interesting question to Usenet.

Oxidisation of Seagate & WDC PCBs:
http://groups.google.com/group/sci.electronics.repair/browse_thread/thread/2242c6be34042a28/12a896fd389028d4#12a896fd389028d4

See Jeff Liebermann’s response.

[MrLeo]

Thank You very much! That was interesting!  So, that means, that WD (and other vendors) doesn’t mean the oxidation of silver plated contacts as a problem, and users continue to solve this problem with a simple soft eraser (as I do it).

Some days ago I tried to buy a new 2Tb WD Caviar Green WD20EADS. It had completely black contacts on PCB being inside a sealed package.