Where is the cold water shut-off valve under the sink ?

[ihatealldiy]

Hi,
The cold water faucet in downstairs bathroom sink has suddenly no water but the hot water works !
I read somewhere that it could be the shut-off valve is closed - but I cannot find the shut-off valve under the sink.
Enclosed a pic - any suggestions ?
Any reason why this has happened just in this sink ?
Many Thanks

 

[terryplumb]

Show us a pic of tap. It's more likely to be an issue with the tap.

 

[ihatealldiy]

Show us a pic of tap. It's more likely to be an issue with the tap.

Pic of the tap and with cap off.

 

[terryplumb]

I assume you can usually turn the white tap head more than one full turn to run the tap on fully , and you still can ,but no water flows ?
The taps cold valve needs to be removed and serviced ,or replaced. Or a complete new tap fitted ,whichever is your pleasure.
You could remove the screw and black part to ensure it's not damaged and does turn the spindle it's connected to

 

[ihatealldiy]

I assume you can usually turn the white tap head more than one full turn to run the tap on fully , and you still can ,but no water flows ?
The taps cold valve needs to be removed and serviced ,or replaced. Or a complete new tap fitted ,whichever is your pleasure.
You could remove the screw and black part to ensure it's not damaged and does turn the spindle it's connected to

Is removal of cold valve easy to do - any links ? Thanks very much for that !

 

[terryplumb]

Turn off mains cold water stopcock and open all taps to drain ,if you have a combi boiler, if hot water is from a tank don't bother draining hot taps.
The valve has a hexagonal head ( just under the black part ,which has to be removed) ,and you use a spanner to remove it ,bracing the tap from moving while you do so.
Sometimes can be hard to remove ,other times it's easy.

 

[ihatealldiy]

Many thanks @terryplumb!

 

[HERTS P&D]

The worm internal part of the tap has come apart. I would advise fitting new tap heads/valves:

tap heads - Google Search

Andy