Samsung Microwave model# SMH7174WC. Both over-the-counter lights will not turn on. Bulbs have both been replaced but no change in status. Also, the fan has three settings (low, high, turbo) but only works on the turbo setting. We think both problems started at the same time.

It is hard task.

• You will need special tools, e.g. Torx screwdriver (star) and other
• Be careful. Oven must be disconnected from mains.
• The disassembling is complicated and procedure consist of more steps.
• Microwave oven lamps bulbs are very special. They often do not have usual lamp cap. See Microwave Oven Lamp Bulb with Base

• Watch this video as example what will your task:

Microwave Oven Lamp Replacement Samsung T170 Light Bulb UK

Some oven lamp types:
Home Office Light Bulbs Microwave Bulbs

What kind of microwave oven is this? A counter-top model or an over-the-range microwave? Do you have a brand and model number? And which light bulb do you want to replace - the cavity light bulb, or the bottom light(s) of an OTR microwave?

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

Good Morning Evelyn, thank you for allowing me to assist you!

Here are some simple troubleshooting tips to help replace the light bulb on your Frigidaire microwave, FMV156DCA.

·First, disconnect power to your microwave. This can be done by either unplugging it or at the circuit breaker panel.
·To release cover, remove the screw on the light cover (light cover may become very hot, do not touch glass when light is on).
·Remove old light bulb and replace only with equivalent watt bulb available from parts distributor or the manufacturer directly. Bulbs are also available at most hardware stores or lighting centers. Bulbs larger than 30 watts are NOT recommended.
·Close light cover and secure with screw removed in step 2.

I hope this information proves to be helpful. If you have further questions, please do not hesitate to reconnect.

This service manual should help you.

If you need to order any parts, the best bet is to get the full model number from the tag in or on the unit and call Encompass toll-free at 866-779-5835.

Remove the screw from the lens cover and open lens. Turn light bulb counter clockwise and remove. Repeat this on other side. The bulbs or 40W appliance bulbs. Take the old one with you to hardware store to match it up. Reverse your steps to put new ones in.

If there's no obvious removable cover over the bulb (most often on the rear or side) and the owner's manual doesn't address it, then disassembly will be required.

You'll need to remove the outer cover (wrapper) to get to the bulb.

Always unplug a microwave before removing or installing any bulbs.

If it's an over the range type, remove the vent grille across the top and see if bulbs can be accessed there. There may be a panel on the bottom covering the light(s), instead.

If not, chances are you'll have to remove it from the wall, then remove the outer cover. If so, the original installation instructions are very handy, and it's best to have two people since the microwave can be heavy and awkward.

Once it's out of the wall, the outer cover (wrapper) will need to be removed, just as you'll need to do on a counter top model.

On a counter top model, be sure it's unplugged, but otherwise ignore the instructions above this paragraph.

You'll need to remove the outer cover (wrapper) to get to the bulb.

See these links before proceeding:
http://www.microwavedisplay.com/safety.txt
http://www.microwavedisplay.com/disassembly.txt

The screws you need to remove should be pretty obvious, but a special driver (such as a T20H type or GTXH20-100) may be needed.

Be sure to put all the screws back in the right holes, since some may be special grounding screws.

Bulbs can be had locally in most grocery stores, hardware stores, home improvement centers, and big box or department stores.

Many models use halogen lamps. You must not touch halogen types with your bare skin, as the oils will shorten the bulb life.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

i know this is going to make no sense . but in my samsung service cd it is in BOLD PRINT YOU MUST DISCONECT POWER BEFORE REPLACEING BULBS , OR DAMAGE TO TIMER WILL RESULT ! the first time you changed them did you disconect power ? if not , your board might be toast , $$$$$$$$$

It is probably more than a fuse which has gone on the microwave and because of the lethal voltages involved with this appliance plus the real risk of a damaging leak unless you have a microwave leak detector and a technical background i would advise finding a qualified technician. Good luck.

If there's no obvious removable cover over the bulb (and the owner's manual doesn't address it) some disassembly may be required.

Always unplug a microwave before removing or installing any bulbs.

If it's an over the range type, remove the vent grille across the top and see if bulbs can be accessed there. There may be a panel on the bottom covering the light(s), instead.

If not, chances are you'll have to remove it from the wall, then remove the outer cover. If so, the installation instructions are very handy, and it's best to have two people since the microwave can be heavy and awkward.

If you don't have your instructions, please reply back with your brand and model number.

Once it's out of the wall, the outer cover (wrapper) will need to be removed, just as you'll need to do on a counter top model.

On a counter top model, be sure it's unplugged, but otherwise ignore the instructions above this paragraph.

The screws you need to remove should be pretty obvious, but a special driver (such as a T20H type or GTXH20-100) may be needed.

Be sure to put all the screws back in the right holes, since some may be special grounding screws.

Bulbs can be had in most grocery stores, hardware stores, home improvement centers, and big box or department stores.

You can order specific Samsung parts here.

Many models use halogen lamps. You must not touch the new one with your bare skin, as the oils will shorten the bulb life.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

We see this a lot. The problem is on the control panel, which we regularly repair nationwide for $39.95 postpaid.

This light failure often occurs when a bulb goes out and the filament shorts, or when the bulbs are removed or installed without first unplugging the oven from the power line. Either can cause such a failure on the controller.

This can often also affect the exhaust fan operation, too. The lights and fan can be inoperable or stuck on too.

Details of our service and critical safety information and disassembly information is at our site, and our link is at our listing here on FixYa: http://tinyurl.com/yzjozk

We're happy to help and we appreciate your thoughtful rating of our answer.