Samlex 1223 (& 21/25) Power Supplies

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Yaesu FP-1023
Kenwood KPS-15

The most common failure you will come across is these three capacitors. They will bulge from the top when they have (or will) fail. When you buy a used Samlex, open it up and check for these three capacitors. If any are bulged, replace all of them to be safe. Be sure to use a quality part, preferably Japanese or something other than Chinese.

What tends to cause these failures is two fold - They were probably pushed to their limit quite a bit, and also, the part is apparently “just enough”. Repair notes I've seen state to take the 2200uF/25V capacitor, and replace it with anything higher than 2000uF and use one rated for 50v to avoid this issue.

Q1, Q2

The other common failure that tends to be seen is the main pair of Mosfets. Once again, probably being pushed too much. Easy way to tell if they are bad is to test each leg with an ohmmeter. They will all short to each other if they are bad. The ones I had replaced had a little burn discolouration at the top heatsink portion.