Samsung microwave oven is dead, power to the plug, removed the cover and found two fuses, removed each and tested with a VOM. reading of 0.03 ohms each?? I believe the fuses are good. What else could be bad? The unit is a SMH7174

make this test and fix it. God bless you

1. Inspect the power cordUnplug the power cord and check for voltage at the outlet. Also inspect for damage, shorts, or burn marks that can be a possible safety hazard.
   
2. Bad door switchIf your microwave does not work at all and you know everything is plugged in properly and the outlet is functioning, then also check the door hooks and the door release button. Using a volt-ohm meter on RX1, check your terminals. When your microwave door is closed you should have a reading of zero. Once the door is open the reading should change to infinity. If these readings do not match up, replacement of the door switch is necessary.
   
3. Blown fusesTo determine if your fuse has blown out, which may attribute to your microwave not running, you need to pull the fuse out using a pair of fuse pullers. Lay it down and using a volt-ohm meter on RX1, check both ends of the fuse in question. If you do not get a reading of zero, then you will need to replace the fuse.
   
4. Bad fan motorLocate the fan and remove the leads. Again using the volt-ohm meter on RX1, check the terminals. If an infinity reading is displayed, it means that the fan has gone bad and requires replacement.
   

First check is the main fuse of the unit. On countertop units, you will need to take the shell off. The fuse will be close to where the cord comes through into the unit. OTR units, this main fuse is usually behind the control panel or possibly behind the vent. Usually the fuse is obvious if blown, otherwise test with an OHM meter, if open, replace fuse.
Some brands will also have a thermal cut-off fuse in the incoming voltage line to the control board. Older Maytags and Samsungs have this fuse in it. This thermostat looking fuse is usually above the oven cavity somewhere under the outside shell. Sometimes you can get to it through the vent of OTR models. Test with an OHM meter, replace if open.
remember use VOM. God bless you

Try using the VOM
First check is the main fuse of the unit. On countertop units, you will need to take the shell off. The fuse will be close to where the cord comes through into the unit. OTR units, this main fuse is usually behind the control panel or possibly behind the vent. Usually the fuse is obvious if blown, otherwise test with an OHM meter, if open, replace fuse.
Some brands will also have a thermal cut-off fuse in the incoming voltage line to the control board. Older Maytags and Samsungs have this fuse in it. This thermostat looking fuse is usually above the oven cavity somewhere under the outside shell. Sometimes you can get to it through the vent of OTR models. Test with an OHM meter, replace if open.

First check is the main fuse of the unit. On countertop units, you will need to take the shell off. The fuse will be close to where the cord comes through into the unit. OTR units, this main fuse is usually behind the control panel or possibly behind the vent. Usually the fuse is obvious if blown, otherwise test with an OHM meter, if open, replace fuse.
Some brands will also have a thermal cut-off fuse in the incoming voltage line to the control board. Older Maytags and Samsungs have this fuse in it. This thermostat looking fuse is usually above the oven cavity somewhere under the outside shell. Sometimes you can get to it through the vent of OTR models. Test with an OHM meter, replace if open.Remember use the VOM.
God bless you

First check is the main fuse of the unit. On countertop units, you will need to take the shell off. The fuse will be close to where the cord comes through into the unit. OTR units, this main fuse is usually behind the control panel or possibly behind the vent. Usually the fuse is obvious if blown, otherwise test with an OHM meter, if open, replace fuse.
Some brands will also have a thermal cut-off fuse in the incoming voltage line to the control board. Older Maytags and Samsungs have this fuse in it. This thermostat looking fuse is usually above the oven cavity somewhere under the outside shell. Sometimes you can get to it through the vent of OTR models. Test with an OHM meter, replace if open. Use the VOM
God bless you

First check is the main fuse of the unit. On countertop units, you will need to take the shell off. The fuse will be close to where the cord comes through into the unit. OTR units, this main fuse is usually behind the control panel or possibly behind the vent. Usually the fuse is obvious if blown, otherwise test with an OHM meter, if open, replace fuse.
Some brands will also have a thermal cut-off fuse in the incoming voltage line to the control board. Older Maytags and Samsungs have this fuse in it. This thermostat looking fuse is usually above the oven cavity somewhere under the outside shell. Sometimes you can get to it through the vent of OTR models. Test with an OHM meter, replace if open.
use the VOM, God bless you

Hi,
As in your case the fuse keeps on blowing, thereare couple fo things that you will have to do fix it:
The problem your describing is most likely a cap problem. The transformers operate in saturation and therefore it's not likely to blow out the diode. The transformer is essentially energy limiting.
The capacitor or diode may be bad. Discharge the capacitor as described earlier in the article. Test the capacitor by removing the leads and setting the VOM to RX100. Probe the terminals. The reading should start in the low ohms and increase toward infinity. Reverse the probes and re-test. The reading should do the same thing. If not, it's bad. To test the diode, disconnect the diode from both the appliance and the capacitor. With the VOM set to RX100, probe the wires. Then reverse the probes and read again. You should get infinity for one reading and low ohms for the other reading. If not, replace. Another cause could be a faulty magnetron, but due to the sensitivity of that piece, it's best left to a professional.
http://www.doityourself.com/stry/repairmicrowave
You can see the diagram of you model in order to do further repairs by going to the below mentioned link:
http://www.appliancepartspros.com/partsearch/modelsearch.aspx?model=JVM1651
Choose you model no. and on the next page on the extreme left you will see the diagram of you model, click on the diagram to see a enlarged image.

Whirlpool is conducting a safety recall on the Kitchenaid KHMS155L series (and similar models under other brand names) that display the F2 code or have been observed self-starting. Other symptoms may be additional codes or unintelligible info being displayed, and failure to execute the command entered into the control pad. To obtain free replacement of the control panel, call Ava at Whirlpool: 1-866-640-7146, extension 6337. She will want your complete model and serial numbers and a phone number and address where you can be reached. She will arrange for A & E Factory Service to contact you to set up an appointment to come out and replace the control panel at no cost to you.

Had the same problem. Removed the unit (snapping off the upper and lower trim rings was a chore but they do snap off) and tested the power. Plug behind the unit was good. Pulled the cover and checked the thermal fuse with ohm meter. No good. Replaced fuse, microwave would run for a second, then light goes dim and it buzzes, then it blew the fuse. Per above suspected Capacitor. Changed that, and we are back up and running. Thanks!!

Make sure unit is not plugged in. Use a Volt-Ohm Meter, on Ohms setting, and see if you have connection to the fuse holder. Put one meter lead on the BLACK ac wire, test the ac plug with the other lead (both sides) One should read. Do the same with the WHITE ac wire. One should read.If you get readings on both sides then AC Cord is good. Next check the fuse holder for signs of heat or dis-coloration. If found replace fuse holder. Always remember just because a fuse looks good does not mean it is good, and also I have replaced a fuse with a NEW bad fuse. It happens. To be sure test with meter.