8RDA Needs Surgery

[uthungover]

{BC}Helix, Low ESR = Low Equivalent Series Resistance. They are designed for high frequency switching applications which is the case in the mainboard power regulator circuit. The higher the ESR the higher the ripple voltage so you might have stability problems with standard capacitors. I realy don't know if there is the potential for damage or not. You might try to find the data sheet for the new capacitors and compare them to the ones you replaced.

 

[{BC}Helix]

If I were to in the future have stabilty problems, if there any way i could get my hands on some of the originals, or would I have to take them off of some other Epox board?

 

[uthungover]

I think these should be direct replacements for the originals. To be sure let me see if I can find the specs of the originals on my board tommorow and I'll get back with you.

 

[uthungover]

Ok, here is what I found:
GSC RE series Low ESR are the ones on my board that are failling.
Comparing them to the NICHICON UPM Series

.................Ripple Current (mA)........Impedance (Ω max)..........Load Life
GSC.................1580...........................0.030......................1500 hours
NICHICON..........1655...........................0.038......................5000 hours

These specs are for the 10v 2200 μf capacitor. Notice the difference in the rated lifetimes. These look like an ideal replacement, the only thing is the NICHICON caps are 2mm bigger.

 

[{BC}Helix]

Thanks alot for that info. I might look in to purchasing same of these just in case. Do you know of any resellers that would carry them online, or can I get them right from mouser? Are they 2mm bigger hight or thinkness wise, the ones I have installed now are about that same size, as you can see from the picture I posted. I seem to have plenty of room.

 

[uthungover]

Yes, you can order them online from mouser (www.mouser.com), they are on page 449 of their online catalog. Just pick the value and voltage you need. The 2mm difference is the diameter, 10mm for the originals vs 12mm for these.

 

[g0dM@n]

Hi... I just wanted to say... nice thread, good read.

 

[McTimson]

I too have had problems with the same 4 capacitors, all of them were bulging, and 2 were leaking. I've been having odd problems like CD drives not working for a while, and never even looked at them, I only noticed it when I took the motherboard out to replace it with an NF7-S. It was also randomly restarting a few times in the few weeks before I replaced it, and I think that's what caused it. I took out the 4 caps today, and plan on getting some new ones soon....as well as putting at least some heatsinks on the mosfets, because look what happened to the back of the board....

Anyone else's back look like this? Originally, I thought it was from the caps, but after I took them off, I realized that it was the mosfets...

 

[xAlucarDx]

Great thread, I have an 8rda+ as well so it cought my eye. I looked at mine and there don't appear to be any problems but I have a fairly light overclock so I'm not that worried. How long have you guys (the ones with problems) had your motherboards?

To replace them is it just a matter of unsoldering the old ones and soldering in the new ones? or is there anything special you have to do?

Kind of off topic> where did you all learn about this kind of stuff... are you self taught or did you go to school? have any good electronics links?

 

[g0dM@n]

Not that I was really a part of this thread, but I graduated with a B.S. in Physics. Basically, I took a few classes that dealt with electronics, and on top of that I took two electronics courses (one as an elective).

That picture two posts up of the melted solder at the bottom of your board... I must say that, in my opinion, the more your MOSFETs melt the bottom the closer they will get to the board. The closer they get to the board, the more they will get hot. I would put heatsinks on that very soon.

Same goes for capacitors, if they are getting too hot (even if they're not leaking yet)... you're already deteriorating its purpose. You're weakening them as they keep running hot, and if they melt the bottom solder they will only get closer to your board; thus, making it hotter and hotter. When I used to build electronic kits we were taught to leave a space of about (not sure EXACTLY how much) 1/8" from the board... better for heat dissipation. Basically, if you're going to resolder new caps make sure you leave a space between the board and the cap.

 

[uthungover]

MOSFETs or Capacitors will never get hot enough to melt solder. I don't see any melted solder in his picture. The power regulators on newer boards use the board as a heat sink so they must be mounted flush to the board. The heat is probably what is causing the discoloration on McTimsons board. I don't think I'd worry to much about that. As for capacitors, I would mount them flush to the board also. There is realy no reason to hold them off the board, they're more stable (mechanicaly) if they are mounted flush.

 

[g0dM@n]

Okay, fine. Everything I said is 100% incorrect. You'd be better off saying it like that.

If you're not using high-quality caps you would keep some distance from the board.

 

[uthungover]

Okay, fine. Everything I said is 100% incorrect. You'd be better off saying it like that.

If you're not using high-quality caps you would keep some distance from the board.

I would'nt say it like that. On older boards the FETs were mounted vertically with heatsinks attached. In this case space under them might be beneficial. It's just not the case anymore, at least on the newer boards I've seen. Capacitors realy don't produce that much heat. In a mainboard they are usually heated by the inductors, regulators and the cpu which they are in close proximity to. Good radial lead capacitors are designed to be mounted flush to the board (the have a plastic spacer under the leads). Axial lead caps may be a different story, i.e., they may need space under them. The only thing I would say your mistaken on is the components melting the solder. You would have a fire before the solder would melt.

xAlucarDx, In my experience the amount of overclock has little to do with it. My 8kta3+, which was heavily overclocked, lasted alot longer than my 8kmm+ at stock speeds. It's just a case of faulty capacitors. If you have to replace them remove the old ones using solder wick then resolder the new ones with good rosin core solder. The capacitors are polarized so don't put them in the wrong way. The capacitors will be marked + or - and the board should be marked also. You can get everything you need at Radio Shack except the capacitors themselves.

 

[Oni]

Great thread, I have an 8rda+ as well so it cought my eye. I looked at mine and there don't appear to be any problems but I have a fairly light overclock so I'm not that worried. How long have you guys (the ones with problems) had your motherboards?

To replace them is it just a matter of unsoldering the old ones and soldering in the new ones? or is there anything special you have to do?

Kind of off topic> where did you all learn about this kind of stuff... are you self taught or did you go to school? have any good electronics links?

I've had my motherboard for just over a year. I think it was about 6 months old when I bought it. It's going to a good home soon, however. To somebody who's better at soldering than I am

 

[McTimson]

The melted solder in my pic is because I had just taken the bursting capacitors out...that stuff was from a soldering iron.

 

[g0dM@n]

Sorry, I don't quite know the exact thermodynamics behind solder as a material.

Anyways, are things better than before, or just the same?

 

[{BC}Helix]

Great thread, I have an 8rda+ as well so it cought my eye. I looked at mine and there don't appear to be any problems but I have a fairly light overclock so I'm not that worried. How long have you guys (the ones with problems) had your motherboards?

To replace them is it just a matter of unsoldering the old ones and soldering in the new ones? or is there anything special you have to do?

Kind of off topic> where did you all learn about this kind of stuff... are you self taught or did you go to school? have any good electronics links?

After I replaced mine I did seem to be getting better stabilty. Right before I took the old ones out I was getting quite frequent restarts, so I think thoes caps were the problem and not my power supply like I had suspected earlier. I'm keeping a close eye on these new ones though, I hope there a good enough quality to stay in the board. Soldering thoes things out is a huge pain, you have to pull on the leg and heat up the solder at the same time. It's a little easier if you have two people like I did, but it still takes forever to wiggle thoes things out.

 

[imaboutaquit]

I am in the process of sending out my rev 1.1 8rda+ for the same condition, just on different caps-the ones located to the right and under the vid card. I happened to be sitting in front of the pc when it died. Screensaver just stopped, never to reboot again. Stops at the c1 POST error. Should be in the mail for rma tommorrow. I dont believe this to be an epox only problem. I read an article a while ago-it may have even been a post here-about a stolen formula for the electrolyte solution for caps in general. Somehow the formula got messed up and MANY caps for MANY different applications will be effected by this in the future. I recently replaced a shuttle board for the same problem.

 

[imaboutaquit]

found the article-interesting. http://www.spectrum.ieee.org/WEBONLY/resource/feb03/ncap.html#f1

 

[G-PHoRCe]

i saw once an article about some dude who changed all the capacitor on his mobo with some better quality capacitor (i think sanyo or something) well the dud e was off with better oc and voltage stability...i'll try to find the article again...