Hi All,

We had a power flash at out house (lights flickered).
And our Sharp R21LCF microwave went out at the same time.

Looking at the service manual for my Sharp R21LCF,

https://www.dsvendinginc.com/images/...als/R21LCF.pdf

I see that cause of a completely dead machine is the Monitor
Fuse (figure O-1 at the bottom of page 9).

Why they call it a "Monitor Fuse" is beyond me.

The manual says (page 12):

If monitor fuse is replaced, the monitor switch must
also be replaced. Use part FFS-BA033WRKZ as an assembly.

Here it is on Amazon:


https://www.amazon.com/Sharp-FFS-BA0.../dp/B001RCHEWC

It shows both the switch and the fuse separately.

Why can't I just replace the fuse (1-1 on page 34)?

Many thanks,
-T

On Monday, May 20, 2019 at 12:40:13 AM UTC-4, T wrote:
Hi All,

We had a power flash at out house (lights flickered).
And our Sharp R21LCF microwave went out at the same time.

Looking at the service manual for my Sharp R21LCF,

https://www.dsvendinginc.com/images/...als/R21LCF.pdf

I see that cause of a completely dead machine is the Monitor
Fuse (figure O-1 at the bottom of page 9).

Why they call it a "Monitor Fuse" is beyond me.

The manual says (page 12):

If monitor fuse is replaced, the monitor switch must
also be replaced. Use part FFS-BA033WRKZ as an assembly.

Here it is on Amazon:


https://www.amazon.com/Sharp-FFS-BA0.../dp/B001RCHEWC

It shows both the switch and the fuse separately.

Why can't I just replace the fuse (1-1 on page 34)?

Many thanks,
-T

maybe because they know that if there is a short that blows out the fuse, often the switch is also damaged.


are you sure that the fuse is the only thing damaged? or is it just the _first_ thing that you found?


I would jumper the fuse with another fuse temporarily and see if everything else works, or if the new fuse immediately fails

It seems to me those switches are UNDERATED for the amount of power involved.

I think they are saving pennies counting on the fact that the door switch usually does not make or break while power is flowing. In other words avoid opening the door while the oven is running.

m




m

On Monday, May 20, 2019 at 10:01:28 AM UTC-4, wrote:
On Monday, May 20, 2019 at 12:40:13 AM UTC-4, T wrote:
Hi All,

We had a power flash at out house (lights flickered).
And our Sharp R21LCF microwave went out at the same time.

Looking at the service manual for my Sharp R21LCF,

https://www.dsvendinginc.com/images/...als/R21LCF.pdf

I see that cause of a completely dead machine is the Monitor
Fuse (figure O-1 at the bottom of page 9).

Why they call it a "Monitor Fuse" is beyond me.

The manual says (page 12):

If monitor fuse is replaced, the monitor switch must
also be replaced. Use part FFS-BA033WRKZ as an assembly.

Here it is on Amazon:


https://www.amazon.com/Sharp-FFS-BA0.../dp/B001RCHEWC

It shows both the switch and the fuse separately.

Why can't I just replace the fuse (1-1 on page 34)?

Many thanks,
-T

maybe because they know that if there is a short that blows out the fuse, often the switch is also damaged.


are you sure that the fuse is the only thing damaged? or is it just the _first_ thing that you found?


I would jumper the fuse with another fuse temporarily and see if everything else works, or if the new fuse immediately fails

It seems to me those switches are UNDERATED for the amount of power involved.

I think they are saving pennies counting on the fact that the door switch usually does not make or break while power is flowing. In other words avoid opening the door while the oven is running.

m




m

Where did you see the rating for the switch? Your idea that it's because
they think the switch could also have been damaged sounds right. Or it
could be that they make more money on parts by making you but the two,
I guess.

On 5/19/19 9:40 PM, T wrote:
Hi All,

We had a power flash at out house (lights flickered).
And our Sharp R21LCF microwave went out at the same time.

Looking at the service manual for my Sharp R21LCF,

Â*Â*Â* https://www.dsvendinginc.com/images/...als/R21LCF.pdf

I see that cause of a completely dead machine is the Monitor
Fuse (figure O-1 at the bottom of page 9).

Why they call it a "Monitor Fuse" is beyond me.

The manual says (page 12):

Â*Â*Â*Â*Â* If monitor fuse is replaced, the monitor switch must
Â*Â*Â*Â*Â* also be replaced. Use part FFS-BA033WRKZ as an assembly.

Here it is on Amazon:


https://www.amazon.com/Sharp-FFS-BA0.../dp/B001RCHEWC


It shows both the switch and the fuse separately.

Why can't I just replace the fuse (1-1 on page 34)?

Many thanks,
-T




Follow up:

Well now, four screws on the back and one screw on the side of
the cover and the cover pulls back and up and off. From the
back, the fuse is staring at you in the upper left corner.

Ace Hardware
Eaton Bussmann Microwave Fuse 1/4" x 1-1/4" 20A
upc 5172-24950
$4.49 for two BP/ABC-20

And now I have a spare fuse. And I know how to change
the lamp too, if that ever burns out.

And to answer my question, there is no reason why
I have to replace the entire assembly. Hmmmmmmm

Thank you all for the tips. This was an extremely easy
fix!

-T