It is possible and even likely especially if they have been stored in place that has high temperatures. There is gradual evaporation of the electrolytic that depends highly on environmental variables.

Somewhere in the Vogons, there is a thread with a picture of NOS motherboard with bulging caps, mobo is from capacitor plague era. Never thought that caps could be of that bad quality, before seeing such thing myself.

Yes, it is possible. I open 20+ year old "brand new" stock from our warehouse at work, and sometimes I see bulging/leaking capacitors. Sometimes they look fine, then they'll blow up/fail when you plug it in. For critical equipment, they all get recapped before even powering them up or installing them. For non-critical equipment, it gets a 48hr burn in test before installation. Our rule of thumb (actually EPRI standards) is to recap everything after 10 years.

I bought a "new" Abit VH6-T board (that's about 17 years old?), most of its caps were bulging. It was boxed up like it was new but I have pretty much the same concern you do - surely they'd only bulge if they'd had current run through them? Maybe the caps from the cap plague era just leak regardless of use?

Like Baoran says though, storage probably has an effect too, maybe hot temperatures through all the summers its been around for, contributed to the leaking.

This happened to me twice, with a DFI Socket 370 motherboard (which like yours didn't work even after recapping) and an Antec power supply. Both items from the capacitor plague era (early 2000s). I have my doubts if the motherboard was really new, but the power supply definitely was, shrink wrap, smelled like new, everything packed perfectly. And the PSU works perfectly now after a recap.

So yes, I'd say it can happen.

Bottom tier caps like Fuhjyyu or Chhsi don't require much stress to fail. They should be replaced regardless of age, operational history, or storage environment.

I bought a NOS Abit KT7A a few years ago. It was definitely never used when I got it.

The first time I turned the power on multiple caps exploded. It gave me quite a scare.

It was kinda funny in the end as there was pieces of paper from the capacitors plastered on what it was near when I turned it on.

Ended up replacing all the caps of that type that were on the board and it worked just fine.

Caps from the plague era definitely can fail in storage.

Non-plague ridden caps I wouldn't worry too much about unless you're either obsessive or are having problems with the part.

The only other caps I'd worry about are tantalum caps that are 25+ years old and haven't been powered on before. New old stock cards from the 80s and early 90s with tantalum caps should definitely be tested carefully. If they work the first time though, they're probably fine for 25 more years.

I think if anything electronics that have been stored without use are more dangerous. The eletrolytic fluid in capacitors will evaporate overtime when powered on, but it is dissolves much less slowly when not in use. Meanwhile, literal battery acid is eating through the cap as soon as the fluid is placed within it, and overtime it can convert to a hydrogen gas and pressurize. With 90's boards I would bet that it is more likely you have a few bad capacitors than you don't. I recently recapped my SS7 board. The caps around the VRM were completely dry. Taiwan logo printed on every one of them.

I have bought NOS motherboards from Soltek and QDI last year, because they were new, complete, cheap and have a rich feature set. They are all from the early 00’s. The Solteks already had visible capacitor leakage. The QDI board had one capacitor that blew up after 5 minutes of use. All bad capacitors were from questionable Chinese and Taiwanese brands. I have replaced all large elcos with either polymer capacitors or Japanese elcos, which was not cheap.

In contrary, I also have some old motherboards with Japanese elcos (Nichicon, Rubycon, Sanyo, Panasonic, Chemicon) and they all still work with the original ones. Usually the better capacitors can be found on motherboards from Intel, Tyan, Supermicro, some OEM (mainly 90’s IBM, COMPAQ, Dell, AST, Siemens) and on the high end Asus and AOpen motherboards. Other manufacturers like MSI, Gigabyte, Soyo, PC Chips, ECS, DFI, Abit, QDI, Soltek, Foxconn etc. mainly have used poor capacitors.

Here’s a lesson that I have learned: if you don’t want to go through the time consuming and expensive hobby of recapping, then pay a little bit more for a good motherboard in the first place 😉

Thanks for the replies. The motherboard was a Soyo 5EMA Socket 7. The caps that were bulging (which were nearly all of them) were some unknown brand with an F, maybe "Fuhjyyu".

The board was meant to be new, but it was clear that at the least, the box had been opened and parts taken out. I really doubt it was new. Either way, I think I've learned that buying used and tested is probably safer than buying new when dealing with old mobos. It's slightly contrary to what I would have originally thought (new is better), but probably not in this case.

I dunno, even the 'best' brands weren't immune from cap failure, from my experience. I've pulled MANY bone-dry Sanyos out of old Asus motherboards. While better than the usual suspects, they haven't proven to hold up that well over time to me.

Synaps3 wrote:

Thanks for the replies. The motherboard was a Soyo 5EMA Socket 7. The caps that were bulging (which were nearly all of them) were some unknown brand with an F, maybe "Fuhjyyu".

Fuh Yin, perhaps?

They can go bad and bulge while in storage for sure.

My experience is that I have not had to recap anything that is more than 20 years old. 1998 and onwards, I find bulging caps, I replace them. I am not as picky about brand and origin as most people on VOGONS, I use virtually no name stuff if that is what I have. It seema even the bottom tier of today is better than what was around 1998-2004.

During the plague era though it very rarely happened they still would go bad while the boards were still on store shelves as they were that bad, I don't stress over caps and just replace as needed or just put it away till later.

I just replaced about 25 Nichicon caps on an Asus TUSL2 due to bulging. Brand on the cap nor the board makes any difference when it's from the cap plague era.

I recap and re-fan every PSU that isn't brand new as a matter of course. Motherboards, I am planning to start at the PII era and work my way out - up to P4 and back to my oldest 386 era stuff. It's worth the time and effort to keep things running safely. When I get done with that, I'll move on to re-lubricating floppy and optical head rails.

Comes with the territory.

SirNickity wrote:

I just replaced about 25 Nichicon caps on an Asus TUSL2 due to bulging. Brand on the cap nor the board makes any difference when it's from the cap plague era.

I recap and re-fan every PSU that isn't brand new as a matter of course. Motherboards, I am planning to start at the PII era and work my way out - up to P4 and back to my oldest 386 era stuff. It's worth the time and effort to keep things running safely. When I get done with that, I'll move on to re-lubricating floppy and optical head rails.

Comes with the territory.

What kind of soldering iron/tip do you use for recapping?
This was my first time recapping and I just used two soldering irons at the same time. This wasn't a very good method and I still left a few questionable ones in. Is there a better way? (Maybe it's ubiquitous because I haven't spent much time researching the subject.)

Motherboards are tough as hell to solder, I use a 60W soldering station with a wedge tip. I set the soldering iron to 400C, and mix some 60/40 leaded solder in with the non-leaded solder to lower the melting point and help transfer heat into the joint, especially if the joint likes to absorb heat.

I am considering the following soldering iron upgrade:

https://www.banggood.com/Mini-V3-0-T12-Digita … ur_warehouse=CN

to make it easier to get heat into the joints that I solder.

I use a Weller iron and a small chisel tip. I don't remember exactly what kind/size it is. It can be a real pain to get some of them out, especially the ones attached to a ground plane. I started to figure out that I had better luck holding the iron gently against the exposed leg on the bottom of the PCB. Before that, I was trying to heat the annular ring, and probably transferred the majority of heat into the board rather than melting the solder around the leg. YMMV. Mixing in some new leaded solder probably helps as well.

hakko fr-301 has made desoldering much easier for me. Caps generally just drop off easily on the table when using that.