Asus Cuv4x-d

[hackerbob]

I have this mother board and it always appeared to be sluggish from day one. I bought it new and it has worked very well with dual p3's until I started to receive XP BSOD's and linux kernel failures. These started off being random then it would not load the OS.

I have since replaced it with a newer MB but I have some older ISA cards for serial ports that I would like to continue to use since they still work. I used this box as a internet gateway and general pupose Linux server( DB, FAX, File Server, Router etc. ) .

Long story short the Sanyo 1500uf 6.3v WX series Caps( 16 total ) are bulging and some have dielectric on the top of the can. I pulled one and the capacitance on my meter measured 2.83mF. I expected it to be lower! Maybe I damaged it removing it.

ALso, Is there an easy way to remove these caps it took a lot of heat to get it out. I usally melt the solder and rock it out without much problem but these were different. It almost seemed that the solder would not flow.

What is a good replacement CAP? I lhave used rubys before and they seem to hold up well. I imagine the dielectric is the important component depending on usage. Since these are all the same type WX I think I could use the same type of a newer cap.

Rob

[PCBONEZ]

Re: Asus Cuv4x-d

Sanyo rarely fail.
Perhaps the power supply did them in.
Don't put this board (or any other) back on that PSU without checking it too.

Motherboards are thicker than most PCBs and you have to get the heat all the way through the hole. Too small (watts) of an iron means long time to heat all that up.
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You should use a 60 to 80 watt (or even 100 watt) iron for removal.
You want max heat and smallest TIME on the board to minimize possibility of damage.
If you only do this sort of thing occasionally then a $10-$15 cheapie iron is fine.
If you are near a Fry's Electronics they have a 60 watt cheapie for $9.
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Use fluxed solder braid. It helps.

Sanyo WX series is directly comparable in specs to:
Rubycon ZL
Nichicon HD
Chemicon KZE

That grade (or better) should be easy enough to source.
.

[PCBONEZ]

Re: Asus Cuv4x-d

Sanyo 1500uf 6.3v WX - Ripple=1820 - ESR=0.023

[hackerbob]

Re: Asus Cuv4x-d

I was amazed to find a sanyo but given its location and usage it is not a complete suprise. Most of the 16 are right next to the heat sinks of the cpu I imagine that A LOT of heat energy moves throught that area. Also they are tall, more surface area to absorb heat and located close together. All the sanyos were bad even those located away from the cpu's and other non-sanyo caps were fine( no bulging ).

Maybe the power supply could have been the problem I do not use it anymore because it is lower power and does not fit the newer MB's.

I have a weller EC2002M soldering station I think that is only 60w I turned it all the way up around 860 and it still took a while. It usally takes more heat to de-solder anyway but I seldom go over 700. I do not have flux braid but I have flux in a paste that works when added to the braid I do have. There is such a samll amount of solder that I thought the braid would be useless. I will try it when my replacements arrive.

Thanks
Rob