2016-07-06

A jimby oven repair.

Our Fisher & Paykel oven failed a month ago and I made the mistake of jumping to conclusions and ordered a pair of new triacs because the elements were fine but not operating, then later I suspected the opto chip was crook as I wasn't getting voltages that made sense from the output despite the input working as it should. This piccie shows the replacement opto that I fitted which I even made the effort to put a socket in for.
Of course fitting the new opto chip and the new triacs which finally arrived today made no difference as during my testing I'd used this diagram as a reference. Today I did some real checking and noticed the orange and red wires should be fitted in reverse, little wonder I was surprised the oven wouldn't turn off during my testing.
 So I decided to get serious about looking at the board and the darkened area at the oven drive end of the board was very suspicious, I had put it down to 19 years of service but one leg of the capacitor was loose and these bad eyes of mine finally saw it. I think because of that it caused that transistor to fail, which then led to Jimby donning a loupe and checking his box of semiconductors, deciding on a lesser replacement that hopefully will be OK as its max voltage is 30V Vs 50V of the original but the capacitor being rated 16V should mean it's OK, its current rating is slightly higher. I replaced that capacitor too with a 25V rated part.
Anyway testing after finally getting the triac wiring right has things working fine and we have a very happy Olivia.
Almost back together.
I had a month of cold sweat nightmares thinking about putting the fan cover back in place, then it dawned on me that Olivia might manage it far easier than me, a few seconds later she'd done it, I can stop feeling pain thinking about it now.

No comments:

Post a Comment