FIXED JJW9530CCS Jenn-Air range not maintaining temperature

[brenthompson]

Model Number

JJW9530CCS

Brand

Jenn-Air

Age

More than 10 years

Set the oven to 350. Once it gets there (this takes the normal amount of time), turn it off. Wait 5 minutes. Turn it back on (i.e. set it back to 350). Display indicates it's say 320 and preheating. Relays click (sounds like the K1/K2 relays with their 51 second/8 second cycle at the link below), but oven doesn't heat up. Leave it like this 5 minutes, turn it off, turn it on again, display now indicates say 280 and preheating, but again it's lying, it's not heating. If I wait long enough and the temp gets down to ~150 (not sure of the exact temp where it decides to work, seems to vary), it'll start heating again and get back up to 350. Then the cycle repeats itself.

I found this diagram on your site and it appears to match up to my circuit board - WP74006614. I'd replace it if I could but I can't find one anywhere.



When I first started looking at the problem, I noticed burnt solder on the DBL pin on K8. I re-soldered it and things improved (it didn't work at all before - what I'm describing now is current behaviour). I then replaced K8 (original was Omron G8P-UA-006204, replaced with T9AS5D12-12). No improvement.
I then replaced the temp sensor (WP 12001656) and lower element (WPW10310258) since they seem to be the common culprits in cases like this, no improvement.

About the only things I have left to change are
1- the upper element, but it doesn't seem likely to be the culprit
2- the high-limit thermostat (WP7403P899-60). On this model is this thing a thermostat or a thermal fuse? It would make sense if a bad thermostat was telling the oven not to heat due to over-temp. But if it's a single-shot fuse, it's not the culprit. I've tested it at room temp and resistance is 0 ohms.
3- the circuit board WP74006614, but again I can't find a replacement.

I do have a circuit diagram for the main board:


If you don't think it's the upper element or high-limit thermostat, can you suggest what component on the board might be at fault? This post which I re-read often talks about a sail switch but the sequence of events doesn't seem to match up, since my fan doesn't turn on until the oven has heated up.

 

[Dan O.]

the circuit board WP74006614, but again I can't find a replacement.

This supplier shows a rebuilt one in stock however you might want to contact them to confirm availability.

LINK > Wall Oven Relay Control Board WP74006612R

high-limit thermostat (WP7403P899-60). On this model is this thing a thermostat or a thermal fuse?

It appears to be a thermostat.

Dan O.

 

[brenthompson]

They seem to have WP74006612R and WP74006613R but not a 14. And both of those seem to be missing K8, some resistors, the DBL / L1 pins, etc so they don't look like a good match? Any guess as to what functions I'd lose by using one of these boards?

I'll try replacing the thermostat.

Thanks for the quick reply

 

[Dan O.]

They seem to have WP74006612R and WP74006613R but not a 14.

I'm sorry. That's the second time that site did that to me. I'll have to stop using it as a reference.

There are a couple of repair services for that board listed here:

LINK > WP74006614 Repair Services


Dan O.

 

[brenthompson]

Replacing the thermostat didn't fix it. After more debugging I'm back to the original problem. When it's working, there's 120V from L2 on the BAKE pin by K1 and alternately on the BROIL pin by K2 and another 120V from L1 on the DLB pin by K8, so there's 240V when measured between BAKE and DLB. When it's not working, there's no L1 appearing on the DLB pin, only L2 coming back through the element from BAKE/BROIL, so 0 V between BAKE and DLB.

Referring again to this post comment, does my circuit board WP74006614 have a sail switch? If so, what does it look like, and any idea where it is on the circuit diagram I posted originally?

Any idea what else would prevent 120V from showing up on the DLB pin, other than a bad "sail switch" or a bad board.

 

[Dan O.]

Referring again to this post comment, does my circuit board WP74006614 have a sail switch?

1. You do realize that message is about a different make and different model of appliance? Not all appliances are made the same.

2. Look to see if one is shown in your model's wiring diagram. If not, there likely isn't.


Dan O.

 

[brenthompson]

To close this off for any future searchers, I did end up fixing this.

Re: Dan O's questions / comments,

1. Yes, I am perfectly aware that the post I referred to was for a different make and model of oven, but it was extremely similar. There's no good big database of circuit diagrams out there and this was the closest reference I could find.
2. The text on the circuit diagram I found is in a foreign language. The term "sail switch" sounds like industry slang, not an actual component name, which is why I was asking what it was / looked like. I assume based on its name that it's a switch that's closes based on air flow? In any case, I recognized all of the symbols on the circuit diagram and board so concluded there wasn't one present.

I'd like to be able to say "replacing X fixed it", but I can't cause I'm not sure which of the changes I made actually fixed the problem. I did lots of testing after each change but still can't say for sure. Maybe it was a combination.

I ended up replacing the temp sensor (WP 12001656), lower element (WPW10310258) and high-limit thermostat (WP7403P899-60). I noticed that the plastic frame that holds the circuit board was actually bending it backwards a bit, and caused some components to separate from the board slightly. I de- and re-soldered the loose components and when reassembling the oven I didn't fully secure the board back in the frame - I clipped one end in and left the other end sitting loose on top of the frame. I then laid the frame down in the path of the cooling fan.

All the components I replaced tested ok at room temp, but maybe one of them was failing at high temp? Don't know. But it's been a year now and no failures. If something similar were to happen again I'd start by replacing the usual suspects, cause they probably cause the majority of problems, even if the symptoms aren't the "classic" ones you find online.

 

[Dan O.]

There's no good big database of circuit diagrams out there and this was the closest reference I could find.

There's one in every appliance (plus usually a 'tech sheet') when it leaves the factory. It's best to locate and use it. Even if you find a copy online it could be outdated.

the circuit board was actually bending it backwards a bit, and caused some components to separate from the board slightly. I de- and re-soldered the loose components

That sounds like the most likely cause. Elements are not usually intermittent (I've never heard of a single case) so it could have been ruled out immediately.


Glad to hear you got it working. Thanks for the followup.

Dan O.