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Magic Chef Electric oven Model #59FN-5TVW No Bake or Broil or Self Clean


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8 replies to this topic

#1 tumblin'man

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Posted 10 January 2012 - 08:56 PM

Do I need a new ERC board for this electric oven? Here is the situation.

This is an electric oven that will not bake or broil. But the display works and so does the light and fan.

This is what I did to diagnose the problem:

First, I measured the sensor which is good since it measures 1075 ohms at room temperature.

Next, with my meter at the control board terminals, I read 240V across the control board's L1 and Bake relay terminals with the oven plugged in and in standby. This means to me that there is continuity through the bake element and the limit switch.

Next, keeping the volt meter leads on the L1 and Bake relay terminals, I turn the oven controls on to the Bake setting. The voltmeter continues to read 240V. So the relays are not closing (if they closed, I would get a 0 volt reading across the relay terminals). Then after about 30 seconds the bake display shuts off, and the meter still reads 240V.

Then I did the same thing with the L1 and Broil terminals on the control board and got the same results.

So, it seems like the Bake and Broil elements are good (at least there is continuity through them), the limit switch is closed (there is continuity through this), and the sensor is good.

Does it need a new circuit board?

Thanks to anyone who helps. It will be much appreciated.

Edited by tumblin'man, 11 January 2012 - 05:58 AM.


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#2 Samurai Appliance Repair Man

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Posted 12 January 2012 - 05:37 PM

Howdy, tumblin, sorry this one slipped by! Let's see what we got here...

Next, with my meter at the control board terminals, I read 240V across the control board's L1 and Bake relay terminals with the oven plugged in and in standby. This means to me that there is continuity through the bake element and the limit switch.


Your conclusion that you have continuity through the bake element and limit switch are true if and only if one side of the element is hard wired to L2 so that one of the spades on the element always has 120vac when the oven is in standby. Do you know that this is the case?

Also, in looking into this one, I noticed one of the parts that get called up with this model number is the infamous relay board in addition to the ERC. Does this model have the relay board?

Reasons I'm asking is that it does indeed appear that neither the bake nor broil relay are closing but the question is what role, if any, does the relay board play in that circuit. Would need to look at the wiring diagram to know that.

Could you post or send me the schematic to the range so we can both look at together? You can post a photo here or fax it to me at 866-315-4504.

#3 RegUS_PatOff

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Posted 12 January 2012 - 07:48 PM

me too ...
Which Relay Board do you have...
(2) Relays and a bunch of Diodes ?
(3) Relays and no Diodes
Is there 120v Ac at the input of the Transformer
and 24v AC at the output of the Transformer ?
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#4 tumblin'man

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Posted 13 January 2012 - 12:55 PM

Wow, just when I was thinking I was way too long winded with my question and was making everyone’s eyes glaze over, I get not one but two replies, and both from supreme masters with 20,000 plus posts. That's great.



Thank you both for your careful reading of my question and your answers. I do want to get this right.

1. I don’t know for sure that one side of the element is hard wired to L2. I assumed it was.

2. I don’t have a wiring diagram for this oven.

But I have a wiring diagram from a similar electric oven from a similar era which uses a similar ERC. I figured that schematic would be better than nothing to use as a guide. That schematic is attached below and is from a Maytag electric oven. The clock/control boards are so similar I figured I was on safe ground using the Maytag schematic.

Here are pictures of the two ERCs. The first is from the Magic Chef : http://www.repaircli...01P17760/709224


This one is from the Maytag where I used the schematic as a guide: http://www.repaircli...lNumber=ECWE900


You can see the two ovens use very similar boards, so maybe It's okay to use the substitute schematic??



3. I assumed the ERC had the relay board attached to it. The ERC seemed 2-layered (I think). Could the relay board be elsewhere in the oven, that is, not in the control panel? The components were on a board behind the black display, which is where L1 and Bake, L1 and Broil terminals were located and where I attached the meter leads.

4. I don’t know which relay board I have. I will find out.

Attached File  Maytag Electric oven schematic.pdf   148.42KB   4 downloads

5. I don’t know the input and output voltage of the transformer. I will find this out too.

The ERC for this oven is 7601p177-60. That is the part number that I saw with my own eyeballs on the ERC itself. The ERC fior the Maytag is 7601P156-60. Very similar.

Does this help you help me? I apologize for making this post so long, but I didn't know how else to say it.

Thank you Honorable Samurai for your generous offer to look at the schematic with me. May good fortune smile upon you always.

thanks again for your help.

Edited by tumblin'man, 13 January 2012 - 01:00 PM.


#5 Samurai Appliance Repair Man

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Posted 13 January 2012 - 01:03 PM

But I have a wiring diagram from a similar electric oven from a similar era which uses a similar ERC. I figured that schematic would be better than nothing to use as a guide.


Well, you know what they say: Close only counts in horseshoes and hand grenades. The circuits can vary significantly from model to model so having a schematic for a "close" model does no good.

You could use eyeballs & ohm meter to trace out the L2 side of the element circuit and determine whether or not it's hardwired.

Is the tech sheet missing from this range? Have you looked behind the range, taped to the back panel? Pulled the pots drawer all the way out, looked in back of compartment and underside of drawer? Gotta have the schematic for that exact model or, if using a substitute, you need to nutz-on know that it's also valid for the model you're working on.

#6 tumblin'man

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Posted 13 January 2012 - 01:39 PM

Okay, Message received and understood. I'm going to look all over the oven for that tech sheet. It was a wall oven and I didn't pull it out. Not because I'm lazy, just because I didn't want to do any damage to any cabinetry so I hesitated, assuming electric oven circuits are all about the same and pulling the unit out wasn't absolutely required.

I have to go back there to get the control board anyway, so I have another chance to find the tech sheet and do more tests.

Where would L2 go if it doesn't go directly to the element?

If L2 does go direct to the element, is it the board that is at fault (assuming the relays are on the board)?

I was thinking that I could jumper between the L1 and Bake leads and see if the bake element turned on. I assumed it would, but now I gather that I shouldn't try this without a schematic.

Thanks again Samurai.

#7 Samurai Appliance Repair Man

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Posted 13 January 2012 - 01:46 PM

Where would L2 go if it doesn't go directly to the element?


It may go to that relay board. No telling what the engineers were smoking when they threw this thing up on the drawing board!

If L2 does go direct to the element, is it the board that is at fault (assuming the relays are on the board)?


From your measurements, it does indeed appear that the ERC is not completing the circuit. What makes me suspicious is that BOTH bake and broil relays are apparently bad-- this is very unusual and suspicious in itself. That's why I want to nail down the status of the relay board.

You could check to see if you're getting coil voltage to the relays. It'll be something in the low volts, 12 to 24 AC or DC, not sure on this one. Can also check the continuity of the relay coils.

#8 tumblin'man

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Posted 13 January 2012 - 01:56 PM

I didn't think both the bake and broil relays were bad. I assume they just are not being commanded to be turned on, by an integrated circuit perhaps. Is it unusual for both not be be commanded to be turned on?

In the bake mode both bake and broil relays should turn on. If one did not turn on, I would assume the relay was the problem. If both don't turn on, I would assume it was an integrated circuit.

If the broil element doesn't turn on in the broil mode, it seems that could also be the integrated circuit.

Does this seem unlikely to you?

I would like to see if voltage is going to the relays, if I can get my leads in the right spot.

thanks again

Edited by tumblin'man, 13 January 2012 - 02:13 PM.


#9 Samurai Appliance Repair Man

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Posted 13 January 2012 - 04:20 PM

You're right on both elements getting power during pre-bake, I overlooked that. But definitely repeat the test while activating the Broil circuit and post your findings.




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