Bad capacitors: where from?

[mockingbird]

Re: Bad capacitors: where from?

I thought the point of a standby chip was to provide only as much current as the device attached to the circuit requires... Only thing connected to the USB port that was active was a wireless NIC... How much amperage would that draw with the computer turned off?

[tom66]

Re: Bad capacitors: where from?

My computer pulls 8W in standby with no USB devices attached. Even at low load, due to the flyback configuration of most standby supplies, ripple current can be significantly higher than the load current (3~4x).

[mariushm]

Re: Bad capacitors: where from?

That's a very inefficient stand by, tom. Maybe disable wake on lan, wake on keypress, stuff like that.

I have an Athlon something on the workbench that I have just to connect scope to it and other things like that, and with a crappy no-name power supply, it still uses only 3.7w when turned off.

All this talk almost makes me plug my main pc in the power meter again but I usually never restart this computer so unless there's a power failure, it's not gonna happen.

[tom66]

Re: Bad capacitors: where from?

Tell me about it, with it pulling 180W idle it's a ridiculous energy sink. I've got to build a HTPC which will be always on... and I want to aim for 10W idle... got a long way to go!!

[Behemot]

Re: Bad capacitors: where from?

You want 10 W in idle? Yeah, maybe with some tablet…

[jasee]

Re: Bad capacitors: where from?

Depends on what you mean by essential if doing this for a living then yes if just hobbying/occasional fix then perhaps not. Firstly you have to understand the results and be able to find a data sheet. The cost has to be offset against number of caps you (save) re-use. I am lucky in that I live near a Farnell outlet so no postage so I would have to save a lot of caps to get a £70 meter. They can save time but if you have to take the caps off board to measure, then how much time? Again there are loads of posts discussing the pros and cons of this and fairly recent one regarding ebay meter you query. I thought of getting one just for interest sake I thought they were a bit cheaper but as the £££ has just gone tits up perhaps that is reflected.

The meter I've mentioned is just about £25.
I've just taken all the capacitors of a board, replaced a couple with low capacitance but still the monitor displays the same fault (switching on the backlight then switching it off after a second or ). Is it possible that the capacitors have high esr but good capacitance?