Hey this is all super useful info, thanks! Any idea how to visually identify a tantalum cap? I suppose I could Google it but maybe standards have changed between 1984 and 2020?
On Thu, Apr 23, 2020, 8:06 PM Jon Elson via cctalk <[email protected]> wrote: > On 04/23/2020 12:53 PM, Robert via cctalk wrote: > > I'm under caffeinated and not really with it yet, having recently gone > semi > > nocturnal, so you'll want to double check this with someone who's > actually > > awake. > > > > That said, variacs aren't a universal panacea and can sometimes be > harmful > > rather than helpful. My disorganized memory is offering TVs as an > example, > > but take that with a pinch of salt. I've only ever used them with tube > > radios and amps, so have nothing further to offer, save this caution. > > > Well, if the power supply is all linear, a Variac is > probably fine to slowly ramp up the capacitors and > let the dielectric reform. > > If it has switching power supplies, this can cause the > supply to try to operate at severe undervoltage, and cause > damage. On the other hand, powering it up to 10 V or so on > the AC input for a few minutes > is unlikely to allow the switching stage to start up, but > will reform the main input storage caps. > It won't reform the low voltage caps in the rest of the > unit, though. You could apply low voltage > (1-2 V for a minute or two) to each low voltage rail before > fully powering on. Especially if it > has bunches of tantalum caps in the logic, that could > prevent disaster. > > Jon >
