For various reasons (mainly old age), I have several 20-30 year old Futaba and JR servos, and some even older Cox Sanwa ones.
Noticed today that some of the connectors have a nasty geen colour. (See pic)
They could remain green or turn black for all I care, except that I have 3 models awaiting completion since long, so I need 12-15 std servos.
Asked RC Aunt for advice. She said 'Put some nimboo on it'.
So I gave one connector a few drops of lemon for 4-5 secs, then a shot of WD40.
Now it looks shiny golden! (See second connector in same pic)

Is it safe to use now? Or would the wires also have got petrified?
Advice requested...

Here's the pic

Hi sir,
           Very nice idea, It is copper sulphate.I can be cleaned by any acid like lemon juice.it is advisable to put some vaseline or any other lubricant so it doesn't corrode easily.

Thanks.

Please take out from its housing then clean and use it.

Lemon juice will clean those areas it can reach

But these will corrode right back again. Vaseline, or any oil, while inhibiting corrosion to an extent, will hinder conductivity

Best is to use a Contact Cleaner Spray like CRC Electro-Clean or CRC Contact Cleaner or Cramolin Contact cleaner

CRC is available online ( Amazon, eBay)

http://www.industrybuying.com/industrial-cleaners-crc-SP.B2.1630227/?utm_source=Google&utm_medium=PLA&utm_campaign=PLA_Cleaning&gclid=Cj0KCQjwnubLBRC_ARIsAASsNNkByg0qJZBvrn_omt6bbeOW03WibVTwB_NbJXYt9t9Bvhm2lvL773saAiu-EALw_wcB

http://www.amazon.in/CRC-2-26-POWER-SPRAY-500ml/dp/B00R96ZASU