Electrolux fault code help please!

[NME308]

Hi Guys,
I have an Electrolux ESD24HRA inverter split system. It is probably around 5 years old and has been going quite well until around 3 months ago.

Three months ago I went to fire it up for the first time since the previous summer and all it had were flashing lights on the indoor unit. Long story short it was gecko (lizard) pee on the outdoor control PWB. The local repair guys reconed all the pwb's needed replacing. I'm an office equipment technician and regularly wash alcohol and roach defication from niteclub cash register pwb's so I did the same to the air con boards and it all worked fine!

Three months on and the unit has suddenly stopped cooling. The indoor fan comes on and displays no error codes. Neither heating or cooling modes change the air temp coming from the indoor unit. The immediate thing noticeable at the outdoor unit is the LED on the main PWB is flashing 3 times in quick succession followed by a second bread and flashing again. The large outdoor unit fan comes on and every few minutes it seems the unit resets and tries to reboot again.

Any clues??

As a technician looking outside my speciality I'm leaning toward the 4-way valve as it makes a whine/hum at times - noticeable soon after startup or what I believe is the unit rebooting. Just yesterday when I was doing further testing it started making a rattling/clunking noise and when I tapped it lightly with screwdriver handle it would chanage between hum and rattle.

Cheers,
Jason

[NME308]

I have done some further measuring and testing.

The compressor is a DA150A1F-20F and it appears to be a 3 phase compressor by the online documentation I can find. Measuring the ohms between the 3 connectors gives 1.1ohms whichever 2 are measured at any time. Also there is no continuity between any of the compressor connectors to ground.

Once the outside unit has powered up the large fan there is around 2 minutes or so until it applies 310V DC to the compressor for around 5 seconds. The compressor vibrates a little then voltage is dropped and compressor does no further action from my observation of around 5 minutes.

There seems to be a constant 10V DC applied to each of the 3 compressor terminals from the main logic board via 3 piggyback connections to the relay(?) board where the large capacitor connects to and the 3 wires down to the compressor originate from. Seems from the main board to be compressor phase check?

I have cleaned the contact points between the temp sensors and their respective pipes etc. with emery paper. The temp sensors all seem to read very similar ohms and the thermal device on the compressor reads almost double the others.

The measurable and observable symptoms seem the same whether starting the unit in heating or cooling mode.

Cheers,
Jason