Have a Mitsubishi Heavy Industries Split system AC Model SRK80ZEA where the indoor unit operates as normal but outdoor unit does not start, so no cooling. Power ok to both units, no error indications.

Get the model number of your mini split unit (on tag on indoor unit and outdoor unit) Google hitachi error codes. You should be able to pull up a code list for that unit. I believe it may be a communication problem between the indoor and outdoor unit. Possible bad connection of wire going from outdoor to indoor unit

Sounds like the filter or coil is dirty, therefore fan amount up and hindering drainage. Vacuum drain, clean coil, change filter.

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Most likely, there has been an operational fault that has triggered a "lock out". This happens when either a mechanical or electrical component has failed, misreading, or if the system has lost refrigerant. You can try to reset the system (both indoor and outdoor units). That might restart it, but a repairman should be called to pinpoint the issue that caused the fault. There is a diagnostic procedure that can help with the diagnosis, but it involves opening the outdoor unit to read the LED's on the control board.

R22= 70-80psig
R410a=120-130psig
Depending on many variables such as blower speed, coils clean, indoor/outdoor temps.

Why does my heat pump ice up in Winter?
Heat pumps naturally ice-up in the winter. It is normal for the entire coil to be covered in a white frost and even light ice, during cold weather conditions. However, it is bad for the entire unit to be encased in ice. This indicates ductless heat pump problems which should be addressed quickly to save energy and avoid serious damage to your ductless unit. These systems should periodically go into a defrost cycle. This keeps the unit running efficiently. If the coils are blocked by ice, proper heat transfer between the coil and the outside air will not occur.
How does the defrost mode work?
When the mini split heat pump goes into defrost, the reversing valve inside of the outdoor unit is energized, switching the system from heat to the air conditioning mode. The outdoor coil becomes the hot, the indoor coil becomes cold, and both - the outdoor and indoor fans shut off. This allows the outdoor coil to melt accumulated ice. When the built-in micro-computer analyzes that all ice have been melted, the heat pump heating system goes back to heating mode.
A cloud of water vapor may be seen rising over the outdoor unit and a "whoosh" sound can be heard as the refrigerant reverses direction. The entire process usually takes up to 10 minutes (depending on conditions).
How often does the system goes into defrost mode?
Ductless mini-split heat pumps have different ways of determining when to go into defrost. The built-in microcomputer determines outdoor temperature, refrigerant pressures, and several other factors. In colder temperatures the system will go into defrost more often than in warmer.
If a ductless mini split heat pump is severely iced-up in the winter it is possible that it isn't defrosting (though there could be many other causes). Let the manufacturer certified technician check your system

To reset it, remove the power plug and then restart.

Please write how many times blinking and with an interval. Depends upon it, we can give solution.

Normally, blinking 5 times means for drain motor malfunctioning. Check drainline, oif blocked clean it. If drain motor not working, replace it.
If blinking 2 times, Indoor room air thermistor defective replace.

Thanks.

There is no CS code. Please read as C5.
Fault Code 05 and 53 (CH05 is displayed at indoor unit, 53 is displayed at outdoor unit)
This fault code indicates a communication error between the indoor and outdoor units; this is usually caused
by wiring errors or condensate pumps connected to the inter-connecting cable.
The communication between the units is a fluctuating DC voltage commonly called a serial signal, it can be
easily lost if the wiring is not done correctly. If there is a communication error fault CH05 will appear within 5
mins of powering up the system.
Testing
• Check Outdoor and Indoor Power Supply Voltages ( 230V ±10% ) and correct as necessary.
• Check for any mis-wiring or loose connections and correct as required.
• Check the resistance between communication line and GND. (Normal: Over 2M).
• If one Indoor unit operates normally Outdoor PCB is generally normal.
Turn on the power and start the indoor unit in cooling, set the temperature to 18ºC; the serial communication
signal will only be present for the first 3 mins of operation.
Set your meter to DC Volts, Test between terminals 5 (Red probe) and 2 or Earth (Black probe) of the outdoor
unit, you should see a fluctuating 0-72 Vdc.
If the Voltage is not present disconnect the terminal 5 cable, test the Voltage between this wire (Red probe)
and 2 or Earth (Black probe), you should see a steady voltage in the range of -0.1 to -10.0 Vdc. If No Voltage
is present either the cable or Indoor PCB must be faulty. This can be determined by checking the voltage
output on the Comms terminal of the Indoor unit, with the Comms wire disconnected. If No Voltage is present
the Indoor PCB must be faulty, if present, cable must be at fault.

sounds like you have a bad coppressor

THE OUTDOOR UNIT HAS A CONTACTOR WITH THE CONTACTS WELDED TOGETHER THE CONTACTOR CONNECTS TO THE COMPRESSOR AS IT TYPICALLY PULLS A SURGE OF 20 -30 AMPS OR MORE..WITH THE INDOOR UNIT IN FAN ONLY THE COMPRESSOR SHOULD NOT BE RUNNING. THE CONTROL WIRES GOING TO THE UNIT HAVE 24 VOLTS TO THE CONTACTOR TO PULL IN THE CONTACTS TO SUPPLY 220 TO COMPRESSOR.