Tech Tips: How to Diagnose a Shorted Power Board (L)

[updated 1/24/2018: Legal disclaimer added]
What does the Noise Filter Board have to do with a shorted Power Board? Watch this Tech Tips video to find out.

[otto]

After paying top dollar for your equipment there should be no shorted boards, this makes me rethink what system to buy.

[jmc]

I have a handheld oscope. A video on wave forms would be great

[MrBig]

Why do you make it near impossible to access the power board on these things???

[PBS-nmuu]

this is a great presentation please keep them coming

[ZEEE]

where do you check your resistance on the power board? is it at the terminals where you removed the incoming power wires?

[diyfirearmsking]

I have a Mitsubishi MrSlim R410A model MUY-D30NA. It’ll start working but then it kicks off and the light starts blinking three times. I’ll go up to the unit on the roof and there’s no lights showing but there is power going into it. Would that be a bad board? I’ve had the mini split for over 8 years and this is the first time I ever had any problems with it. Any help would be appreciated.

[stephenking]

Does the noise filter board keep the unit running quieter?

[wd]

Is this the same for the MITSUBISHI CITY MULTI?

[Robbiebraich]

Hi Nice channel

I have Mitsubishi heatpump which heats up tp 30 minutes & upper green led blinks 5 times repeatedly plz help

[jimsam]

I have a MUZ-D36NA-1, I REPACSED THR POWER BOARD AND THE UNIT BURNED OUT THE NEW BOARD. CAN YOU HELP?

[davidjohnston]

If the power board shorting is a common problem, why is the board designed that way? You didn't explain the underlying cause of the short. What is shorting? A transformer? A capacitor? A power transistor? The bridge? Which is it? If the power board is shorting, there is a reason. We need to know the reason if the underlying cause is to be fixed.

[TheSqhunters]

I have a MXY-3A28V condensing unit .The indoor unit displayed 5 blinks and outdoor 2 Red flashes.i checked the compressor and it was fine.i changed the power board any yet the system does not work.The compressor comes on for 06 seconds and shuts off.Could you help me with this.

[lychinouchongfoung]

Do you thing normal peoples and technicians knows how to troubleshoot an electronic board? Resistance can be check only with one leg out of the board with knowing value of the resistor in ohm. So please just say the board is bad, change it !!!