Kenmore Elite microwave diode rectifier

[cyclopes]

Hi, 

My microwave issue is that it is not heating up the food. i removed the diode and it seems to be shorted. I did the test with a 9V battery and both ways the meter shows 6ish Vots.

I am trying to find a replacement diode with the same markings as the one I removed but with no success. 

Can someone help me identify a suitable replacement diode?

I attached the diode pic and the oven specs.

thank you and best regards.

[daveca]

Odd that it cant be found, Whirlpool is a huge name. Must get the Whirlpool number, it probably wont work to use the markings n the diode.

If for some reason OEM is not available, the term is "Fits-all". Universal replacement.

Get one that is for an oven of the same power rating. Solder on the jumper wire if needed.

The bands- end should be negative.

Always use a dropping resistor when using a voltage source to check a diode forward/ reverse. Diodes can be instantly damaged by over- current or excess reverse voltage.

Silicon diode forward voltages are usually 0.4 - 1.8 V each; these HV diodes are often several in series in the same package.

And be careful, that power supply is around 2-3 Kv! The capacitor charge voltage or transformer secondary voltagd are deadly.

[Vance R]

Seem like sears parts direct has it:

[Budget Appliance Repair]

11 hours ago, Vance R said:

Seem like sears parts direct has it:

MAN!!!  That is absolute robbery there:  $110.00 for a $2.00 diode and a dollar or two in wires and terminals.

[daveca]

That ad " looks" IMO like someone fishing to sell to someone with a built- in unit they have to keep. Sears is gone, so thats not a Sears ad, someones playing games ( I was a Sears Hi Tech tech in the late 80's, as they were screwing it into the ground full stick ahead...)

 

Those diodes were $10 or so in the early 1980s. About $2 to make it 

Critical Question:

Did the AC line fuse blow ?

If the diode shorts, that dumps raw AC on the capacitor and thats a short on the trsnsformer secondary. That ** should*" blow the fuse, unless the diode is open, in which case, "no cook"

Diodes  can be misleading to check out of circuit. Generally, " shorted" means a few ohms resistance both ways.

Any diode rated for 60 cycle at 3Kv or more and maybe 2 amp peak current will work. Four 1N 4007 in series will be 4500 PRV at an amp.

 

[daveca]

PS High voltage there, ~ 2 Kv. Dangerous.

If you dont have a high voltage probe or DMM adapter, get three of the cheap DMMs from Harbor Freight and put them in DC volts 1Kv range in SERIES (Red Black, Red Black.)

 

Be VERY careful to only touch the plastic probe bodies, not metal parts, and that with only ONE hand. Use a clip lead for at least one connection when testing HV. Gloves are a good idea, also make the connections with the oven disconnected and capacitor discharged, then power it up. I saw a Tech knocked across our shop because he used a pair of pliers that had cracked insulation to remove capacitor terminals. That could have killed him!

 

Add the three meter readings to get the total power supply voltage, it should be around 2Kv DC, max of whatever is stamped on the capacitor body.

 

[cyclopes]

Thanks Daveca, 

The fuse is not blown, I am knew to this so I am not sure if the diode condition is short or not. When testing the diode as instructed in a video using a 9v battery, I get the same voltages both ways.

When you say to get a Universal Diode with the same power rating, what am I looking for? Is the power rating specs in the image I have posted?

You also mentioned "Four 1N 4007 in series". Is there a single diode (Besides the Universal) that would do the job. 

Best regards,

[cyclopes]

On 6/4/2023 at 12:19 PM, daveca said:

PS High voltage there, ~ 2 Kv. Dangerous.

If you dont have a high voltage probe or DMM adapter, get three of the cheap DMMs from Harbor Freight and put them in DC volts 1Kv range in SERIES (Red Black, Red Black.)

 

Be VERY careful to only touch the plastic probe bodies, not metal parts, and that with only ONE hand. Use a clip lead for at least one connection when testing HV. Gloves are a good idea, also make the connections with the oven disconnected and capacitor discharged, then power it up. I saw a Tech knocked across our shop because he used a pair of pliers that had cracked insulation to remove capacitor terminals. That could have killed him!

 

Add the three meter readings to get the total power supply voltage, it should be around 2Kv DC, max of whatever is stamped on the capacitor body.

 

Thanks Daveca, 

The fuse is not blown, I am knew to this so I am not sure if the diode condition is short or not. When testing the diode as instructed in a video using a 9v battery, I get the same voltages both ways.

When you say to get a Universal Diode with the same power rating, what am I looking for? Is the power rating specs in the image I have posted?

You also mentioned "Four 1N 4007 in series". Is there a single diode (Besides the Universal) that would do the job. 

Best regards,

[Vance R]

One source can be ebay, there are one like this one. 

[cyclopes]

On 6/5/2023 at 7:24 PM, Vance R said:

One source can be ebay, there are one like this one. 

Thanks Vance but I believe the one I need is Frigidaire Part# 5304474696 Rectifier. But I don't know how different or similar it would be from the one you mentioned.

[Budget Appliance Repair]

The one @Vance R referred you to would work fine but it is still way over priced - if you look up just about any Whirlpool model microwave you would find a diode with a Whirlpool part# and it would be more reasonable priced, probably under $20.

None of them will have the red wire attached - the capacitor where the diode end with the red wire attaches should have two or three male spade terminals so you could snip the diode off the red wire leaving the connector to go to one spade terminal on the capacitor where it originally attached and then use one of the spare spades on that same capacitor terminal to attach the new diode that doesn't have the red wire attached to it.

You can find microwave diodes on Ebay and Amazon under standard diode part#'s not for any specific brand of microwave for under $10.00, (Just did a quick search for "Microwave diode" on Ebay and came up with 9+ pages of them - a pack of 5 for $8.54 or another only $6.32 or make offer for 5 with free shipping - 2 paks for $6.11 or best offer)

 

Edited June 7, 2023 by Budget Appliance Repair

[cyclopes]

On 6/7/2023 at 9:59 AM, Budget Appliance Repair said:

The one @Vance R referred you to would work fine but it is still way over priced - if you look up just about any Whirlpool model microwave you would find a diode with a Whirlpool part# and it would be more reasonable priced, probably under $20.

None of them will have the red wire attached - the capacitor where the diode end with the red wire attaches should have two or three male spade terminals so you could snip the diode off the red wire leaving the connector to go to one spade terminal on the capacitor where it originally attached and then use one of the spare spades on that same capacitor terminal to attach the new diode that doesn't have the red wire attached to it.

You can find microwave diodes on Ebay and Amazon under standard diode part#'s not for any specific brand of microwave for under $10.00, (Just did a quick search for "Microwave diode" on Ebay and came up with 9+ pages of them - a pack of 5 for $8.54 or another only $6.32 or make offer for 5 with free shipping - 2 paks for $6.11 or best offer)

 

Thank you, I got the $8 diode but that did not solve the problem. I got a new Magnetron for about $40 and that solved the problem. No issues so far.

Cheers