I have de-scaled and water pumps fine. Once I put the K-Cup in, the Keurig will not brew. I've cleaned the nozzle and ran the machine without a K-cup in and all is well. Once I put the K-Cup in no dice.

Here is a link to some troubleshooting:
What to Do If Your Keurig Won Brew Cup Barista

Power board is defective and needs replacing

If your brewer is not brewing the full amount selected, it may be caused by the following:

• The exit needle is clogged by coffee grounds or cocoa mix. Please refer to the K-Cup Holder cleaning instructions.
• The brewer may need to be de-scaled. Please refer to the de-scaling instructions.
• The removable water reservoir was removed during brewing. Place the water reservoir back onto the brewer and perform a cleansing brew without a K-Cup.

First try to make a descale maybe repeat it the next day.
http://www.keurig.com/customer-service/brewer-registration-and-support/~/media/FD69E91A51CA41BEBF4CCAA138325BBF.ashx

If your brewer is not brewing the full amount selected, it may be caused by the following:

?· The exit needle is clogged by coffee grounds or cocoa mix. Please refer to the K-Cup Holder cleaning instructions.

?· The brewer may need to be de-scaled. Please refer to the de-scaling instructions.

?· The removable water reservoir was removed during brewing. Place the water reservoir back onto the brewer and perform a cleansing brew without a K-Cup.

First try to make a descale maybe repeat it the next day.
http://www.keurig.com/customer-service/brewer-registration-and-support/~/media/FD69E91A51CA41BEBF4CCAA138325BBF.ashx

Then try also this

http://www.youtube.com/watch?v=DqRs4Ott21s

If your brewer is not brewing the full amount selected, it may be caused by the following:

?· The exit needle is clogged by coffee grounds or cocoa mix. Please refer to the K-Cup Holder cleaning instructions.

?· The brewer may need to be de-scaled. Please refer to the de-scaling instructions.

?· The removable water reservoir was removed during brewing. Place the water reservoir back onto the brewer and perform a cleansing brew without a K-Cup.

First try to make a descale maybe repeat it the next day.
http://www.keurig.com/customer-service/brewer-registration-and-support/~/media/FD69E91A51CA41BEBF4CCAA138325BBF.ashx

Then try also this tip

http://www.youtube.com/watch?v=DqRs4Ott21s

If your brewer is not brewing the full amount selected, it may be caused by the following:

?· The exit needle is clogged by coffee grounds or cocoa mix. Please refer to the K-Cup Holder cleaning instructions.

?· The brewer may need to be de-scaled. Please refer to the de-scaling instructions.

?· The removable water reservoir was removed during brewing. Place the water reservoir back onto the brewer and perform a cleansing brew without a K-Cup.

First try to make a descale maybe repeat it the next day.
http://www.keurig.com/customer-service/brewer-registration-and-support/~/media/FD69E91A51CA41BEBF4CCAA138325BBF.ashx

Then try also this useful tip

http://www.youtube.com/watch?v=DqRs4Ott21s

Hi,

Here is a tip that I wrote that will give you some things to try that will helpyou get your Keurig coffee brewer workingagain.

Keurig CoffeeBrewer not making a full cup of Coffee
heatman101

From http://www.keurig.com/customer-service/brewer-registration-and-support/~/media/Files/Keurig%20Brewer%20Manuals/De-scaling_instructions.ashx
To begin, you will need the following:

• 48 ounces of undiluted white vinegar
• Large ceramic mug (do not use a paper cup)
• Access to an empty sink

PREPARE Step 1: Empty the water in the Water Reservoir. Step 2: Disable "Auto Off" features.
FILL AND CLEAN Step 1: Pour approximately 48 ounces of the vinegar into the Water Reservoir. Step 2: Place a large mug on the Drip Tray Plate and run a brew cycle. DO NOT USE A K-CUP, just press the BREW Button. Pour the contents of the large mug into the sink. Step 3: Repeat the brew process without a K-Cup until "ADD WATER" is indicated. Step 4: Now let the Brewer stand for at least 4 hours while still on. Step 5: Discard any residual vinegar and rinse the Water Reservoir thoroughly.
RINSE Step 1: Ensure the Water Reservoir is filled with fresh water. Step 2: Place a large mug on the Drip Tray Plate and water brew cycle. Pour the contents of the large mug into the sink. Step 3: Repeat brew process until "ADD WATER" is indicated. Step 4: You may need to perform additional water brew cycles if you notice any residual taste. NOTE: If "DE-SCALE" is still displayed after completing the procedure, repeat the de-scaling procedure above.

If your brewer is not brewing the full amount selected, it may be caused by the following:

• The exit needle is clogged by coffee grounds or cocoa mix. Please refer to the K-Cup Holder cleaning instructions.
• The brewer may need to be de-scaled. Please refer to the de-scaling instructions.
• The removable water reservoir was removed during brewing. Place the water reservoir back onto the brewer and perform a cleansing brew without a K-Cup.

The water pump is probably starving for water:1. Remove the clear plastic reservoir and set it aside. 2. Look into the hole that the reservoir sits on. You will see a fine plastic screen that keeps debris from getting to the pump. 3. Clean off the screen. You may have to disassemble the bottom of the machine and remove it to do it right. 4. Put everything back together and the short-cup problem will be history.