• ** REMEMBER! **The microwave can still shock you even unplugged!!

    ALWAYS discharge the high-voltage capacitor first if you even think your hands will come close to any HIGH VOLTAGE components.

    Jeff mentions this: Anything in the high voltage ( magnetron, capacitor, diode, wires to and from ):
    ...Use a metal ( not the shiny chrome type ) screw driver with a insulated handle to short across ( touch both at the same time ) the terminals of the high voltage capacitor to discharge it.

    From Jeff's site: http://www.applianceaid.com/component-testing.php

    Jake

LMV2053ST LG microwave... no power at all, chances fused, still no power

LMG

Premium Member
Joined
Feb 12, 2019
Messages
3
Location
Ocala FL
Model Number
LMV2053ST
Brand
LG
Age
1-5 years
LG over the range microwave LMV2053ST.
The bottom light bulb was burnt so I proceeded to remove it however I broke it in the process. Since the points of the bulb were still in I had my daughter shut off the breaker on the wall, and I used a needle nose pliers to remove them. BOOM! It sparked and popped loudly, my daughter had turned the wrong breaker off. After that there was no power at all to the microwave. I changed the ceramic 20A fuse but still no power. What else should have check or replace?
 

Dan O.

Appliance Tech
Staff member
Joined
Oct 9, 2004
Messages
1,996
Location
Canada
Check for power

Has anyone confirmed power is getting to the microwave now?
 

LMG

Premium Member
Joined
Feb 12, 2019
Messages
3
Location
Ocala FL
Has anyone confirmed power is getting to the microwave now?
I put the new ceramic fuse in then plugged the microwave in, no lights no power. Is there a different way to check if there is power getting to it?
 

Dan O.

Appliance Tech
Staff member
Joined
Oct 9, 2004
Messages
1,996
Location
Canada
LMG; said:
I put the new ceramic fuse in then plugged the microwave in, no lights no power. Is there a different way to check if there is power getting to it?
Measuring with a volt meter or using an outlet tester or test light where the microwave plugs into the wall outlet would be testing. Plugging a lamp or other electrical device into the microwave's wall outlet to see if it worked would be a way to test if there was power there.
 

LMG

Premium Member
Joined
Feb 12, 2019
Messages
3
Location
Ocala FL
Measuring with a volt meter or using an outlet tester or test light where the microwave plugs into the wall outlet would be testing. Plugging a lamp or other electrical device into the microwave's wall outlet to see if it worked would be a way to test if there was power there.
Thank for the replies.
The outlet has power, I took down the microwave and put it on the counter using another outlet which also has power.
 

Dan O.

Appliance Tech
Staff member
Joined
Oct 9, 2004
Messages
1,996
Location
Canada
If the unit is not working at all and power is definitely at its outlet and the internal fuse is good, a failure of the electronic control may be responsible. I can't say whether there could be any other possibilities without seeing the unit's wiring diagram which I don't have access to. On most models there aren't any other components that can stop all functioning.

JMO
 

Dan O.

Appliance Tech
Staff member
Joined
Oct 9, 2004
Messages
1,996
Location
Canada
Check cavity thermostat

.
Ok, I located a service manual for your model and the wiring diagram looks to show 2 thermostats, one of which might stop all power to the unit if it failed. Although not designed for that specific purpose, it might have been damaged because of the short. (It normally fails by getting too hot but it could be a weak point in the electrical circuit and have failed due to the short.)

The one referred to as "Oven cavity thermostat" is the main one needing resistance checking (with an ohm meter). I am not positive exactly where it is located but likely attached onto the oven cavity wall or ceiling. The other similar looking thermostat is mounted on the magnetron tube but if it failed should only stop heating.

LINK > Oven Cavity Thermostat 6930W1A003D

LINK > How do I test for continuity?


If it tested Ok than I can only think the electronic control itself might have been damaged by the short. Unfortunately the control PCB looks to be discontinued. I did find one new one still available for sale if needed:

LINK > LG LMV2053ST Control PCB 6871W1A419K

Dan O.
 
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