Pioneer DVR-225 DVD Recorder Power Supply Issue

[vinljnkie]

This unit I have had since it was new in 2004 and it's recently been acting up. What it was doing was when you would turn it on the display would come on bright for a second or two then revert back to just a dim clock which is how it normally is while in stand by/off mode. I'd sometimes have to press the on button and have it go through this cycle 10-20 times before it would come on and stay on. I suspected bad caps as soon as it started giving me problems but didn't have time to look into it before leaving for the holidays to visit my parents for 3 weeks. When I got back the display was off and it didn't respond to attempting to power up. It is now completely dead. I pulled it out of the entertainment center and opened it up and sure enough one of the caps on the power supply board is bulging (see pic, just right of center). The bulging culprit is a 3300uf @ 10V ELNA RJF series cap. Almost every cap on the board is of this same brand and series except the 2 large caps just left of center which are Rubycon 100uf @ 250v caps. My question is would you just replace the one obviously bad cap or are there others that you would consider replacing while you are at it? I was considering replacing the one right next to the bad one which is a 1800uf @ 25V. Other than this power supply board, the main circuit board is filled with Nichicon caps so I'm thinking it has many years left in it once the power supply is fixed. What do you guys recommend?

[lnx64]

I'm seeing so many blown ELNA caps from around that time period. They must have seriously failed in copying some design from someone else.

[crtfool]

I would replace all the caps on the power supply board with Panasonic FM and FC series caps - this would be your best solution to prevent you from having to make further repairs in the near future. You probably will be OK if you do not want to replace the 2 large filter caps on the AC side of the circuit. If you do not want to replace all the caps, then you should at least replace all the dark brown caps because they are all most likely the same series caps - the blue caps are probably from a different series.

You should test all the caps with an ESR meter if you do not want to change all of them.

[N2IXK]

Generally, the large caps on the line side of a switchmode supply don't fail except from a lightning event or similar. They only handle 120 Hz ripple, as part of a voltage doubler. If they hold a charge, and aren't obviously leaking or bulged, they are doing their job.

The ones that get stressed and fail regularly are the filter caps on the secondary side. They have to deal with high frequency ripple, and heavy ripple currents. Their ESR is much more critical, as well.