[Premium-Rx] HF1000 power supply repair

[Geoff Fors]

This is over-generalizing things but the most common failure mode in switching power supplies, especially those in higher temperature environments, is high ESR of the electrolytic capacitors.  ESR meters are relatively inexpensive and pay for themselves with the first repair.

They are particularly helpful in equipment where no service documentation is available.

I use the Dick Smith Electronics ESR meter (kit) although the new EVB Co. version (assembled, ex-Portugal) at $ 75 is a good buy.  

That might help you avoid dependence on foreign repair facilities, which are shrinking in number, if you decide not to replace the switcher with an analog version.

By the way, many modern analog supplies are noisier than a well made switching supply, due to the rectifier diodes' radiation of hash from shock excitation (easily bypassed), or from the popular design of primary-side regulation using SCR's instead of regular diodes, feeding them with a variable waveform to achieve regulation (not easily bypassed.)  I am still working on quieting down a few Gould modern analog type supplies that are worse than most switchers with RFI!

Geoff Fors
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