My Keurig model D70 does not brew the desired amount even on the travel mug option. On the travel mug option it won't even brew a half a regular size mug of coffee.

I realize you think it does not need descaling to to it 'not being used much.'
However you may have hard water and I would think descaling is definitely worth a try. There might be scale built up on the water level probes in you machine.

Descaling Details are listed below:

Brewer Model: Elite B40 ' Classic B44
Special Edition B60 ' Platinum B70

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.

It may be time to descale. Most models will give you a message when it's time to have the mineral deposits cleaned.
HERES HOW TO DO THAT...
Empty water resevoir. Disable auto off. Pour approx 48 oz of undiluted white vinegar into resevoir. PLace large mug on drip plate, run brew cycle, dump contents of mug in sink. DO NOT USE A K-CUP.
Repeat this process until the add water light is indicated.
Let brewer stand for at least 4 hours while still on.
Discard any residual vinegar in the resevoir and rinse thorughly.
AFTER approx 4 hours...fill resevoir with water.
RINSE:
PLace a large mug on the drip plate and water brew cycle. Pour the contents of the mug into the sink.
REPEAT this brew process until the add water light is indicated.
YOU MAY NEED TO REPEAT THIS "RINSE" PROCESS if you notice any residual taste.

Most models will give you a message when it's time to have the mineral deposits cleaned.
HERES HOW TO DO THAT...
Empty water resevoir. Disable auto off. Pour approx 48 oz of undiluted white vinegar into resevoir. PLace large mug on drip plate, run brew cycle, dump contents of mug in sink. DO NOT USE A K-CUP.
Repeat this process until the add water light is indicated.
Let brewer stand for at least 4 hours while still on.
Discard any residual vinegar in the resevoir and rinse thorughly.
AFTER approx 4 hours...fill resevoir with water.
RINSE:
PLace a large mug on the drip plate and water brew cycle. Pour the contents of the mug into the sink.
REPEAT this brew process until the add water light is indicated.
YOU MAY NEED TO REPEAT THIS "RINSE" PROCESS if you notice any residual taste.

Your b60 may need to be descaled. There might be scale built up on the water level probes in you machine. I have listed the directions below:


Brewer De-Scaling Instructions
Brewer Model: Elite B40 ' Classic B44
Special Edition B60 ' Platinum B70
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
descaling procedure above.

Manual is here...

http://www.keurig.com/help/B30mini_useandcare.pdf?mscsid=4ERVGRF0CN779GJL8ESKBA7FFP6TDX5B

Is the mug clear? It wont like clear glass mugs. or cannt sense offset mugs...

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/lisa_52daba487e5b4d53

It takes about 3 minutes to brew. You cannot use a clear coffee mug (scensors won't detect it)

You should be able to turn it on, Then place k-cup in holder, Then close lid and water reservoir lid will pop up and you add desired amount of water. Then push lid down, place mug under spout and the blue light will light up and you push taht. Within 3 minutes you should have some coffee

How does the coffee get into the cup? If it brews directly into the cup then the amount can be controlled by how much water you put into the maker. If it is a 6 cup then it must hold the coffee in a reservoir. Do you have to push and hold a button to dispense the coffee or do you push and wait for it to fill your cup? If it is the latter then it will need to know how large or small the cup size is. Is there a setting for that? If it is a push and hold method then you control the coffee flow so size is up to you. As far as it being a travel mug or ceramic mug as long as the mug will fit in the maker and sit securely under the nozzle then it shouldn't matter what kind of mug it is.

These brewers (B77, usually from Costco) are defective & Keurig is replacing them with new units @ no cost. Just call the toll free # (866-901-2739) & they will ship out a replacement in 3 to 10 business days. I own (2) of these & they have both been replaced. Even if not the above mentioned model, call them anyway & see what they will do for you......

What model is this unit?
If a B70 or B77, these brewers (usually from Costco) are defective & Keurig is replacing them with new units @ no cost. Just call the toll free # (866-901-2739) & they will ship out a replacement in 3 to 10 business days. I own (2) of these & they have both been replaced.

Per Pages 9 and 10 of Keurig Model B40 Use and Care Guide,
1) turn off the "Auto Off "feature
2) fill empty water reservoir with 48 ozs of undiluted white vinegar.
3. Place ceramic cup on the drip tray and run a brew cycle. Do not use a K-cup!
4. Press the large mug Button
- let Keurig coffee maker fill mug with vinegar & empty in sink.
5. Repeat brew process until water reservoir of vinegar is empty. (remember to open and close lid between each cycle so large mug Button will flash.
6. Rinse the water reservoir thoroughly and fill with fresh water.
7. FINAL STEP RINSE CYCLE
a) place a ceramic cup on the drip tray
b) run regular brew cycles WITHOUT using a K-cup.
c) pour rinse water into sink each time.
d) repeat brew process until water reservoir is empty.
d) perform additional rinse cycles if you notice any residual vinegar taste.
e) if the red "De-scale" light remains illuminated after completing descale and rinse cycles, repeat the descaling procedure above.
Otherwise - you're good to go!