I have a DVD player which also plays DivX, has a USB input etc. (hence I'd rather not replace it if this is an easy fix)...

The DVD player no longer powers up. I can hear a really high pitched whistle, very feint, coming from the area of the power supply. The logo on the DVD player very slowly starts to glow (as if it's fading in) whereas normally it would light up instantly, but that's as far as it gets.

A visual inspection revealed two 10V 680uF caps that look somewhat overweight, on a seperate circuit board dedicated to providing power (the main board with all the logic chips etc. is separate). Either I've been watching too many high-calorie DVDs, or they've suffered some breakdown and had to vent. Their bulging tops do not look very happy. I can't see any other issues upon a purely visual inspection.

Does it seem logical that those unhealthy looking caps are the cause of the failure?

Can I just replace these with standard 10V 680uF electrolytics from eBay?

Am I right in thinking there's no point in trying to diagnose any further until I've at least replaced those caps?

 

Most likely yes. Especially when the thing seems to barely work, replacing the caps is usually the cheap and easy cure. You would want to replace all large electrolytics while you are doing it, just to be sure it doesnt happen soon again.

 

What would you define as "large"?
The only physically large is a 400V 68uF. The rest are all around 16V 220uF or less, and seem to look ok.

Is there an easy way to test a cap without removing it from the circuit?

 

Anything bigger than the last segment of the smallest finger on your left hand is considered a "big" cap.

Just start with the to 680uF caps. I would not bother with eBay. Get some good, low ESR caps from digikey. If you are bothering to do it, do it right. Shipping will be $8 and the parts will be under $1 each.

Not possible to test without removal of caps and don't worry about the small caps.