Originally Posted by TheDarkPhoenix
I am so glad I found this thread. Thanks for the information. One last question though, what capacitors are the right ones to get? I only know how to solder but know nothing about capacitors
... please advise...
Which model TiVo do you have?
On the sticker on the back where the power cord plugs in there is a model number that starts with TCD (unless you have a Series 1, a Direct TV TiVo, or one of the Series 2 models made by Sony, Humax, Pioneer, or Toshiba).
What is that number?
It wouldn't hurt for you to read Wikipedia's page on "capacitor plague".
The power supply will have one capacitor that's physically larger than the rest by a good margin and is rated for 200 Volts or more.
I've never heard of one of those going bad, and unless the top is bulged you should be able to ignore it.
It only deals with the 120 V AC from the wall socket after it's turned into DC, at which point it has some 60 cycle per second, or 120 cycle per second, "ripple" which the big cap filters. This is not especially taxing on that big cap.
It's when that filtered DC is turned on and off (chopped) thousands of times per second to turn it back into lower voltage AC which is turned into lower voltage DC that the capacitors doing the filtering have to deal with that much higher frequency "ripple", which works them a lot harder.
Because of that they have to be "premium grade", so to speak, and because capacitor plague (in the type of capacitor known as an electrolytic capacitor) is caused by a bad electrolytic formula that resulted in caps that weren't up to snuff to begin with, the harder work revealed the flaws much, much sooner than "good" caps would have slowly gone bad from old age.
Those will be the caps that are smaller than the big one and bigger than the few really little ones on the power supply board.
They'll tend to be near the heat sink(s).
The really little ones shouldn't need to be worried about, either.
What you will need are capacitors that are specifically stated to be Low ESR.
(stands for Equivalent Series Resisitance, and basically the lower it is, the better it works in high frequency switching circuits where there's a lot of current moving in and out of them all the time, because the lower resistance means less heat)
But there's still potential for heat, so you also need capacitors rated for 105 degrees Centigrade/Celsius (which is hotter than the boiling point of water).
The kind of general purpose electrolytic caps you find at Radio Shack tend to only be rated for 85 degrees C.
They will need to be the same rating in microFarads (the Farad is the unit in which capacitance is measured) as the ones they are replacing, so if the old one says 2200uF, so should the new one.
The other thing is the voltage rating. It needs to be at least as high as the voltage rating on the one you're replacing, but you can get away with going to the next step up if necessary.
For example, if the original is rated at 10 Volts, but there aren't any 10V units at the same uF in stock, you could go with 16 V units, 25V if you absolutely have to. But you can't drop below 10V if that's what the original one is.
There's another thread around here with some cap lists for different Series 3 models, and I'm going to be adding some info to it soon.
But lets start with which model number your Tivo is, what its symptoms are, and whether you've had the lid off and eyeballed things yet.