Mitsubishi Mr. Slim MXZ-3B30NA PLEASE

[woody3882]

Mitsubishi Mr. Slim MXZ-3B30NA I really need someone to teach this old dog a new trick, Please…
First I checked the outdoor units power supply L-1 has 123 VAC, L-2 has 123 VAC, together they do have 246 VAC. No problem there. Next step I checked CN-601 input, it has 221 VAC. Again no problem. Next CN-611 and CN-621 are supposed to have 12-24 VDC each, they are only showing less than one volt on each (.14 and .28) Then I opened up the inside coil control panel on both inside units to double check, The terminals 1 & 2 are showing 230 VAC but terminals 2 & 3 are only showing less than one volt DC (.24) Both inside fan coil units shut down after approximately six minutes, comp and cond fan never come on. I am really at a loss troubleshooting this unit. All I need is a guiding hand to which I would be very grateful. I have the manuals, schematics, and tools. I just need someone with experience to tell me where to check next or what could possibly be wrong. Test points from the schematic are fine.
Thanks for any input or help.
Woody Ellenton Fl.

[joe-ice]

hi woody not familar with this particular unit but most of them are self diagnostic when it shuts down it should give you an error code through the operation lamp blinking x amount of times then stopping then blinking the same amount of times again .this is also true of the outdoor unit .You need to count the blinks to get a pointer in the right direction

[install monkey]

http://www.mediafire.com/download/kai6a0aegt99uex/MXZ-3C54-6C120VA_Service_Manual_(OBH584).pdf
uk version of multi split- for guidance on fault led's

[woody3882]

Both lamps are indicating (steady on red and yellow) that "all is OK" I wis it were another flashing code then I would have somewhere to go with it. Anyone with experience in theses units PLEASE help...

[joe-ice]

Are the lights on the indoor units flashing a code problem might not be with outdoor unit

[woody3882]

I am getting there slow but surely… Service manual troubleshooting flow chart stats,
1) Check power Supply. Yes 223 volts…
2) is the output from the noise filter P.C. board 208/230. YES 243
3) Is the input voltage to the power board 208/230. ? I can’t locate the correct terminals to check it.
4) Is the input voltage to the outdoor electronic P.C. board 294/325 V.D.C. YES 323 V.D.C.
5) If there is input voltage to the Electronic control P.C. Board. Replace it..

I have to assume (yes I know about assume) that the Electronic Control P.C. Board is bad. Even though I could not validate input voltage to the Power Board, I believe that if it was bad then then I would have no power to the Electronic ontrol P.C. Board..
So All that being said What are the terminal numbers for the Power Board Input. And How can I check the 24 volts power source, what component (terminal numbers and board name) If you are familiar with the Mits. Split systems, please review my findings before I go and spend a lot of cash on a new P.C. board .
Thanks I appreciate your time
Woody