Instruction: Analyze a question and its supporting document. Predicting answerability based on the information provided in the document. Output yes if the document contains relevant information to answer the question, otherwise output no.

Input:
Question: is the LCD display back lit?
Document: There should be a push button for an LCD panel backlight. Currently the LCD display is difficult to read under dim light.3. The LCD panel has room for 4 digits, but only 3 are shown. Hopefully the next version can make use of all 4 digits.
I suppose this was done to prevent accidental switching, but adding a small recess to get a fingernail in would have been nice since you cannot count on carrying a paperclip with you all the time.The second gripe I have is with the construction of the unit. Overall, the plastic assembly seems thin and cheap. The LCD appears to be a generic display and will even display "lbs" for some odd reason. The USB connectors are somewhat loose in holding whatever device is connected to it. This means that unless you are on a completely flat surface, cords will have a tendency to slip out of the device.
But it just does not work correctly. The PortaPow unit, however, works exactly as advertised. [Mechanical Construction]The PortaPow unit has a short extension cable for its USB port. This allows for easy reading of its LCD display. In contrast, the USB Doctor plugs in directly to the USB power adapter, so it may be difficult to read its LED display in some orientations. [Accuracy]The voltage and current resolutions of this PortaPow unit are 0.01V and 0.01A, respectively. The instruction sheet claims accuracy of &lt;1% error in voltage, and &lt;2% for current.
I compared its readings, against those from aDigital Multimeter. The values are consistent within 1%. For example, the PortaPow reports 5.04V (at zero load) while the DMM reports 5.00V. Similarly, the current readings are typically within 0.01A apart. [Power Consumption]The LCD panel on the PortaPow unit consumes very little power (under 4mA at 5V). Other units with LED display are easier to read, but consumes more power (around 15mA for the USB Doctor). This is usually not a problem, unless the power supply is already operating near its limit.
This device was defective on arrival. It arrived as part of a larger shipment that was well padded. Nothing else in the shipment was defective.Only one digit of the 3 digit display worked. The device rattled if something was loose inside.Being a tech geek I decided to investigate. Two screws were laying inside. They would not re-thread into their plastic keeper as either the hole was too big or the screw was too small. I found some replacements in my parts bin and used the replacements. Now, the LCD display connector makes contact and all three digits of the display work.If you are not handy and don't have a collection of very small size screws [approx english size #2], you run the risk of not getting what you paid for.
and even though it hit the ground pretty hard and the back popped off (seems to just be snapped on), exposing the circuit board and wires, it still works.
I bought the panels to recharge my amateur radio batteries. With this monitor, I can set the panels in the best direction/configuration to minimize charge time and I'm back on the air quicker.
Using it to test various USB charging products to rank them in effectiveness. Large easy to read LCD makes it perfect for documenting the results.
The USB port they chose in the design is extremely flimsy and prone to loosening its contacts within just a few weeks of use. A monitor like this needs a sturdy USB port in order to give a reliable reading (so it's not the bottleneck in the test setup), and with USB ports turning out to be as flimsy as they are, this is a star-grabber. The pins in the USB port start creeping upwards so they don't make good contact with the cable being tested. It's quite tricky to bend the pins back down, and I even found that when I tried it on mine, the VCC (+) pin actually got shoved back into the device - there's no backing to it!
The picture shows graphite / black color, but mine is 1995 computer beige :-/The USB cord on this device is VERY short and is attached to the item in such a way that it MUST be twisted in order for you to see the reading on the front of the device. (For MY panel, and for my PC, when this is plugged in, the LCD screen is faced DOWN so I have to twist the cable 180 degrees to read the screen each time.) This does not seem to bode well for the longevity of the item, but time will tell and I guess if I have to re-order at least I might get a grey/black one...I will add that this fell out of the window the other day (don't ask!)
Answer: yes