Welcome to the forum.
How you measure voltage? Software or Voltage Meter over Probe IT Connector? 
I think later will respond someone who have graphic card.
I remember last year with series GTX700 Classified any voltage change over 1212V was visible only with Volt meter and I'm not sure is it same with GTX900 Classified series.

You should use these... Probe IT Connectors. 
Best Hardware Voltage Read Points on Market
 

 

samsunggtx
Hello guys
Now I've checket the power with the voltage meter.
I can increase the voltage to the Class Field controller but when I get over 1500 core than it brings artifacts and by 1510-1520 core crash the driver.
I am very disappointed. Can you please help me now? What should I do next?

You have the GTX 980 Kingpin which has a 1304 base clock and is the highest clocked GTX 980 card from EVGA. I think you've simply reached a physical barrier or your supporting components can't handle the extra voltage. Please list all of your system specs to include make and model of PSU.

And I think you hit some limits, but you should provide some gold power supply, more efficient for GTX980.
That card is nice and expensive and deserve better PSU. He is important same as motherboard.
In some situation better PSU help with more stable overclock but that's not warranty. 
You should continue to play games, I suppose you bought graphic card for gaming, and for week or two try with other drivers or one day after PSU upgrade. 
Try to OC with all software available on market, Precision X, AB, GPU Tweak, everything...
Excellent chip of GTX980 on air hit 1600MHz but that's maybe 10-15% of graphic cards, it's very hard to hit something like that if you don't want to buy from someone who use graphic card and know to overclock. Chances are 1:5 example.
On your place I would try to save 1500MHz...it's most important that you can play games with graphics if you bought because of that.
 

You can't post links before 10 posts.
I know everything... first 3 reviews pull 1600MHz from EVGA GTX980 Classified normal.
And usually people when get good samples show to others and other people have impression that their card is bad if not reach same speed.
But that's not warranty... Your card is start GPU Offset +180 MHz, and you pull maybe 220-230MHz...
I think up to 100MHz over fabric OC is good number... You are very close that number I think...
Did you check what happen with other BIOS versions, I would search on overclock.net for some unofficial BIOS maybe and check power target limitations. My GTX780Ti KPE when I tried to OC in March 2014 hit PT Limit on 1265MHz Boost on Official LN2 BIOS. I didn't want to change on unofficial BIOS because gaming on +200MHz was reason because I bought card. In OC Scanner my card could boost only up to 1140MHz because hit PT limit 115% on that clock.  
But in games, benchmarks, she boost on 1200MHz and have very small space because 115% power limit. 
Between installing unofficial BIOS and push voltage up to 1.3-1.4V on air and risk to card die and later to pay shipping for RMA and gaming on +200MHz on official LN2 BIOS I choose second option.
I would continue to play games, if card is very bad sample she will show that and become unstable on fabric clock and in games sooner or later. If not she will be able to OC something over fabric clock. New drivers will show up, all Maxwell will become 4-5C hotter because NVIDIA will pull more performance from them in next months and buggy games will discover bad card.
If you are not satisfied you can always change with me for my GTX780Ti KPE...  but I don't recommend you.
 

Ok
Which Psu would you Recommend to me

samsunggtx
Hallo
Please help How can I increase the voltage.
I have the BIOS set to 1.275 but it does not change and remains constant at 1,212 volts

The ONLY way to get actual voltage readings on any 980 is with a digital multi meter using the above mentions supplied cable set. 
 
IF you flip the all the dip switches on the top of the card (2 near the left of those cables and 2 on the right rear corner on the PCI side) you will also enable extra voltage. 
 
Trust me, you will get more than 1.212 volts it just will not register that in software. IF you get the Classified Voltage tool that Vince made you can add some serious voltages. 
 
As far as PS's go ..... there's no reason at this time you can't get a SOLID 1000+ watt Platinum unit for a great price. I run a 1200SS Platinum Seasonic which will likely go in a back up box to make room for a 1600 EVGA Ti.  
 
SS

jhowell1030
This might sound stupid...but I can't for the life of me figure out how to change the leds in precision x.

 
 
Click the yellowish arrow to the right until you see this, then when it is like you want make sure to hit "Apply".
 

Most important to pay attention on G2 sign. Not G1.
G2 is compatible with sleeve cables, have longer warranty and better performance.
You can buy what you like, 1KW is today IN, everybody like 1KW,
but 850W is enough for single and dual cards as GTX590/ GTX690.
But 1KW is better for SLI, example if you one day buy card with power consumption as series 700, and want SLI than it's better 1KW because 100-200MHz space should stay after you OC.
But 1000 G2 don't have Eco Mode Switch as 850 G2.

Any other thoughts why I can't change my LEDs?