Remote control functions Ok (ie display appears and settings can be changed), but the air conditioner unit does not respond. Can operate using ther manual switch on the inside unit, but does not get past the initial start up phase. How can you test the remote control device? Thanks Greg

If the panel remains inoperable to control the buttons, you can just use the air conditioner remote to operate the air conditioner. The unit will still read the remote settings and allow you to operate it without a new panel or temperature sensor. The error code will still appear, but the air conditioner will function normally.

Hi, hild, first thing; stop the AC by remote controler, than select the fan option pressing by mode button and next start the AC, wait 8 minutes, if the unit still blows cold air, the thermistor has to be replaced. I hope this was helpful to you! success!

The DeLonghi PACA120E Portable Air Conditioner quickly cools rooms up to 400 square feet and comes equipped with several functions that make operation easy and low maintenance. Its 3 operating modes are supplemented with no-drip technology, an adjustable thermostat, 24-hour timer, and much more. This unit truly takes the work out of cooling medium- to large-sized spaces. Multiple Modes and Functions The DeLonghi A120E-also known as the Delonghi Pinguino PAC A120E-offers 3 operating modes and 3 additional operating functions that make this model versatile and energy efficient. Cool Mode: 12,000 BTUs of cooling power help cool large rooms, offices, or basements. Dry Mode: Reduce room humidity by removing excess moisture from the air. Fan Mode: Circulate air to keep your room comfortable without using a lot of energy. Low, medium, high, and an auto-speed are all included (auto speed selects a fan speed for you). Smart Function: Your AC uses Cool and Fan mode based on ambient room temperature. This function will also select your fan speed and keeps your room comfortable without wasting energy. Sleep Function: Using a low fan speed, the AC gradually reduces operation so your room remains comfortable but the AC runs more quietly and efficiently while you sleep. Boost Function: This function is ideal for the summer months and uses the maximum fan speed to rapidly reduce your room temperature. Useful Features Using DeLonghi's patented no-drip technology, this unit is "dripless" under normal conditions, meaning the AC will discharge all of the moisture collected from the air-so you typically won't have to worry about draining the water. When dehumidifying a lot of moisture in Dry mode, excess water may collect in the internal collection tank. Once the tank is full, the air conditioner will automatically turn off to avoid overflow damage. You can also use the included continuous drain hose as a no-fuss way to eliminate excess water as needed. An adjustable thermostat provides additional convenience by allowing you to set your room temperature. The DeLonghi portable AC will cycle on and off to eliminate over-cooling and maintain the set temperature. Additional Features Washable Air Filter: A washable air filter helps remove allergens and other particles from incoming air and saves you money on replacement filters. Quiet Operation: High efficiency compressor and components result in quiet performance. Electronic Controls: The LCD screen displays the timer and temperature settings, while intuitive indicator lights accompany each operating mode. 24-Hour Timer: This feature lets you program your AC to turn on or off up to 24 hours in advance, so it only runs when needed. Window Bracket: Double window bracket is included with purchase for flexible installation. Self-Diagnosis System: The unit includes a self-diagnostic maintenance system that identifies malfunctions should they occur. Remote Control: Use the full-featured remote control to change modes, set the timer, and select a fan speed up to 23 feet away from the receiver (on the front of the unit). Portability: Easy-roll casters and dual carrying handles make it simple to move this model from space to space.

Here is the operating manual
www.fujitsugeneral.com/.../OwnersManuals/OPManCeilingSuspended.pdf
On Page EN 7 it has the operating instructions for the hand held remote unit. When the word "cool" appears in the display, depending on the temperature that the room is and what the remote is set for, the unit will function in the air conditioning mode.

Signal transmitting/receiving
error
(Indoor controller does not
respond to remote controller
signal.)
During individual unit control
1) Bad contact of transmission
wire
2) Signal transmitting/receiving circuit
is abnormal.
1) Check the transmission wire.
2) Check with another remote controller. If "EO" is
still indicated, replace the indoor controller
board.
If other check code appears. replace the original
remote controller.
P3 Signal transmission error
(Remote controller does not
respond to indoor controller
signal.)
1) Bad contact of transmission
wire
2) Signal transmitting/receiving circuit
is abnormal.
3) Wrong operation due to noise
wave emitted

When you press a button on the RC, does a arrow appear in the top right corner of the RC?

yes we lost our remote but found that our tv remote will control the ac we can adjust settings and temp we just had to push buttons on the tv remote until we figured out which ones did what

If you can't change the settings manually, then the control pad is bad. If you can and the remote won't change the temp or mode then the remote is bad and will need to be replaced.

Check your remote control by using a camera or cellphone camera as your eyes to confirm if the remote control is ok. Point the remote control transmitter to your camera and check if a light emits in your remote control transmitter. If no light then the remote control is defective, but if the light is present then the remote is ok and the unit receiver board itself is defective.

Check also if there is a reset or rst button on the remote control, press the button and test the remote.