Checking Kenmore Microwave Oven Model 721.63259301. Components test okay but no heating. Possible problem with Relay No. 2 in HV circuit. Component test guide says "1. Measure continuity." It does not indicate + or - for continuity checked with power off and lead wires disconnected. If this part is bad, do you still stock them? Since it is soldered to the board, should I replace the entire board? What are prices involved? And, of course, is this relay normally closed or normally open with power off/l20 v. line plug pulled? This determines whether continuity check I made should be + or -, of course:confused:. Thanks much. zuni88

Gene, many thanks for your response/guidance. On this machine there are three "wires" involved with the two connectors you reference. A white wire connects with a yellow at Relay 2; a red and a brown are joined at the high voltage primary (the brown leads to the monitor switch). In any event, with door closed and using "Cook Time" varying from 4 to 8 seconds, my nearly-new auto-ranging Craftsman meter shows from 12.5 to 12.7 volts between those two connectors. Note: The turntable turns and the fan runs normally when I activate the "cook time" cycle, and the oven light comes on at the same time. The oven light also comes on when I open the door. No question about it -- 120 vac is not getting to the primary winding of the high voltage transformer. Any further suggestions or diagnostic tests I can make?
Thanks very much, Ken.

Gene,
Thanks for your response. I checked further with Sears Parts and determined the following:
1. Parts man No. 1 said that relay is Part No. 2183454 and can be purchased at a cost of $30.59 plus shipping/handling charge of $10.99.
He confirmed it is designed for solder attachment.
2. Parts woman No. 2 said that particular relay is only available by purchasing the complete control board at a cost of $83.42 plus a shipping and handling charge of somewhere between $6.99 and 8.99 (she was not sure of the exact amount).
3. Tiebreaker parts man No. 3 kept me on hold for quite some time but finally returned and voted with Parts woman No. 2. As you indicated, it is necessary to replace the whole control board. One cannot buy the relay by itself.
Purchasing the control board, including shipping/handling, would exceed $90. The cost of a new counter-top microwave oven of this type is not much more than $100 in the store. Hence it would not be cost effective to undertake repair either on my own or by having the local Sears store send this one off to Phoenix for them to repair. The local landfill is the best alternative.
Thank you very much, Gene, for your help on this.
Ken

Need failure symtoms, no heat, electronic timer counting down, slight or loud hum??

Gene, the fuse is okay as are all the switches I checked, and this is a simple counter-top microwave unit.
In the high voltage circuit, the rectifier diode reads infinity in both directions suggesting it is not shorted and likely okay.
Using a new 9 volt battery to test the H.V. capacitor as recommended, the guidance says I should normally get a reading of "approximately 9V." I considered 9.49 volts as good enough.
Resistances measured for the H.V. transformer primary and secondary windings are within specification. Neither the primary winding nor the filament winding are grounded. The filament winding resistance is supposed to be "Less than 1 ohm" -- it reads 0.2 ohm, which is less than 1 ohm and I suppose is acceptable. Filament to chassis resistance is infinite as required.
The only other magnetron check says:"Remove wire leads. Install the magnetron seal in the correct position. Check that the seal is in good condition." This calls for a level of practical experience beyond checking circuits. Also, I have no instrument to check leakage, etc. The only tests I can make with the HV circuit energized would be with the unit assembled with cover on, etc., and measure how hot a beaker of water gets. Since it wouldn't even warm my cold cup of coffee, that was a sufficient test!
Unless something in the foregoing suggests the possibility of a loose connection to check, or some minor fix to add to your short list of fuse or switches, I will accept defeat and thank you once again for your assistance.
Ken