Need some help please

[bobolinko]

Working on a nephew's old unit, but it was never ever installed. It's a 12,000 btu mitsubishi mister slim. (The box has never ever been opened till today) I think it was manufactured about 6 or 7 years ago. We wired it up and piped the unit today, and it does not cool. The compressor never kickcs on. The evap fan speeds oscillation, etc all work as they should. I measure 220 on the main voltage input on the compressor power block (110 on either side of the neutral), and also 110 v on the block,on both the evap and comp sides, but there is no 12v DC on the two leftmost pins. I know there is a charge of *****, but I do not know how much. The liquid line got pretty cold when I opened the line after the piping was secured. I don't have any schematics for the system, and have no idea where the 12vdc is supplied from. Is the 12v generated in the compressor side or is it a result of the evap side creating the 12vdc

I'm quite puzzled as to which end I should be diggin into!
Suggestions and any light on the aforementioned would be much appreciated!

Thank you all ahead of time!
-bob

[frank]

Did you follow the Installation Instructions that came with the unit?

What are the model numbers?

[bobolinko]

Did you follow the Installation Instructions that came with the unit?

What are the model numbers?

Yes, I have installed many, and the installation steps were followed.

The Mod# is Ms12tn mitsubishi
Thanks!

[install monkey]

old mitsi used to be power to indoor,power to outdoor and a 2 core 0,75mm for cooling only or a 3 core for heatpump- interconnecting between the 2 units
12vdc accross 1,2 compressor on signal, and 12vdc accross 1,3 compressor and 4 way valve signa

[bobolinko]

old mitsi used to be power to indoor,power to outdoor and a 2 core 0,75mm for cooling only or a 3 core for heatpump- interconnecting between the 2 units
12vdc accross 1,2 compressor on signal, and 12vdc accross 1,3 compressor and 4 way valve signa

Howdy,
Thank you for the response. I don't have the schematic for the wiring, etc. and I do not know where the SOURCE of the 12vdc is.

Maybe some knowledgable fellow will be able to tell me how the 12vdc is supplied, since it is not available on either the Evap nor the Comp terminal connector posts. The 12vdc should be the 2 on the leftmost position on the comp terminal spots but no voltage there!

[passandscore]

This should answer all your questions

http://usa.mylinkdrive.com/uploads/documents/2388/document/MS-09~17TW,TN__MU-09~17TW,TN_Service_Manual.pdf

[bobolinko]

This should answer all your questions

http://usa.mylinkdrive.com/uploads/documents/2388/document/MS-09~17TW,TN__MU-09~17TW,TN_Service_Manual.pdf

Thank you!
You are absolutely correct. Solved the absence of the 12vdc on the mobo due to a sticking relay. Replaced it and all is good! Everything is working as it should now. Thanks again for all your responses. Appreciate it very much. As we say in Hawaii. "Mahalo Nui Loa!" (Thank you very much!)
Aloha!