Hardware Insights Forum

I bought a bunch of these very cheaply (unused surplus stock) after seeing this particular review, which was for the actual SeaSonic branded unit. As far as I know, the Ipex unit seems identical. It doesn't claim 80+ certification but from measurement, it certainly seems to deliver it. I bought 60 of these in around late 2009 and have been using them 24/7 at high load (BOINC crunching) ever since.

For at least 3 years of use, there were no issues. Most are still working and when running don't appear to have issues. The problem is that most of them now have issues starting from cold, power-off state. If left on standby for 10-20 mins, some will start and others can usually be started by grounding pin 16 (green wire, PS_ON pin) in the 24pin connector momentarily. Once started, they continue running without issue. All machines run Linux and often have uptimes in the 6-12 month range, depending on the frequency of power outages at the location. Even if a machine crashes, it could always be restarted immediately, as long as the power hadn't been completely turned off.

I'm not an electronics tech but I did an Engineering degree many years ago so I have a basic understanding and certainly can read and learn. I've done a lot of that lately so I now understand the need to keep the PSU in spec so as not to overload caps in the VRM circuitry of motherboards. This reading also alerted me to the fact that the PSU starting problem would most likely be related to failing caps in the PSU. I decided to bite the bullet and investigate the condition of my ~6 year old PSUs. In the last week or so, I've replaced bulging caps in 7 PSUs, all of which are now back in service and starting immediately from cold without issue. A couple of these were so bad that they couldn't be started even by grounding pin 16. So, it would seem that I need to re-cap the whole 60, plus some others (different brands and formats) that stopped working at some point for no apparent reason as well.

The 60 are SFX format and I would very much like to continue using this format rather than going to standard ATX. I'm retired, so have time to plod along and am happy to do that. The first one I repaired had 3 obvious failures and replacing just those 3 brought the unit back to life. As an experiment, I replaced the same 3 caps on the other 6 units, even though there were other caps obviously bad as well. This has worked in all cases so far. These 3 happened to be the easiest 3 to get at but there are 8 all told with values >100uf that I want to replace as soon as possible. There are other, smaller values that look OK, 10uf, 47uf at 25 and 50V, a couple of which are near the large primary (Hitachi 180uf 400V) which also seems OK. I'm going to buy an ESR meter and test them in circuit to be sure.

These initial repairs were done to gain experience and see if the much bigger job is feasible for me to attempt. For a quick assessment, I just bought some "Low ESR" caps at a local parts store. I fully understand the need to buy good stuff (preferably Japanese) but these were what I could find quickly and I just bought enough for testing purposes. On one side they just have "LOW ESR" repeated several times. On the opposite side they have the brand "S. I." and the various specs underneath, eg. 2200uf 16V 105C. I asked the store for a spec sheet and they actually gave me a sheet for SamXon but apart from saying 0.05 ohms and 1900 ripple, there is no identification of the actual series they are supposed to be. The S. I. brand I got don't seem to have a series and were coded with the same store code as the SamXon brand, which is what is pictured on the website, but even the pictures don't reveal the actual series. I presume the S. I. are supposed to be direct replacements for the pictured SamXon. All this doesn't really matter since I'll replace them eventually with whatever I decide to use for the longer term.

The 8 capacitors I've decided to remove on every unit are listed below. The majority are Ost brand in two series, RLX and RLS. I found a website that had specs for these. For example RLX D10 16V 2200uf were listed as 0.021/3000 and RLS D10 16V 2200uf were listed as 0.018/2770. There is a single cap whose brand is JP CE-TUR, D10x25, 10V 2200uf (with the word "Vent" on it as well) that I haven't yet found data for.

1. D10x25 16V 2200uf - Ost RLX.
2. D10x15 16V 1000uf - Ost RLS.
3. D10x20 10V 2200uf - Ost RLX.
4. D8x15 6.3V 2200uf - Ost RLX.
5. D8x20 16V 1000uf - Ost RLS.
6. D10x25 16V 2200uf - Ost RLX.
7. D8x15 10V 2200uf - Ost RLS.
8. D10x25 10V 2200uf - JP CE-TUR.

My thinking is to support this site and try to purchase what I need from Behemot. The problem is I'm not really sure of what I need. From what I've read, I need to roughly match the ESR and get at least the same, preferably better (higher) ripple. I've seen that people don't have a high opinion of Ost. I've also seen that can size has a big effect on both ESR and ripple and that bigger cans have higher ripple and lower ESR in a given series. The RLX and RLS series don't seem to be much different from each other so I'm wondering if I can find a single replacement. I'm also wondering if I could use 3300uf to replace 2200uf since there seems to be a complete absence of 2200uf in Behemot's lists. I don't have a height problem up to 30 for any cap - the worst would be No. 8 in the list as it's right underneath the overhang of an "L" shaped heatsink. The problem would be getting the new one in. It'll have to go in at quite an angle and then go back to vertical after it clears the underside of the heatsink. The available space is 32mm at best so maybe not possible to use a D10x30. It was hard enough getting the old one out.

Of the D8s. No. 4 could be a D10 as there is enough space around it but the others would need to be D8s. I'm wondering if I could use SamXon RS 3300uf for all the 2200uf ones (except for No. 7) and something like KZH (16V) for the 1000uf D8s. What to use for No. 7 is then the problem.

If anyone has some advice or suggestions, I'd certainly appreciate receiving them. Hopefully Behemot will tell me what I should use.

Thanks for any response.

These seem to be based on the old S12 platform (with the input capacitor being close to its center), just smaller. OST caps are indeed low on quality. May be better than other chinese c(r)aps, I dismiss all of them as they will fail in end too. And indeed they do, I have already seen bloated OSTs in those newer OEM versions of S12II (Bronze).

So I think stand-by rail caps are getting bad in there. Do you have ESR meter? If you wish to wait, I have Chemi-Cons KYB 2200/16 being manufactured, I expect them in september or so. Both RLS and RLX are more of a motherboard-grade capacitors,that is why the low ESR. But I have no problems at all with Samxons RS 3300/16 and Chemi-Cons KYA 3300/6.3 in Seasonic PSUs so far so I think you can use it without problems. Those D8x15 6.3V 2200uf are heavy-custom variants, I can only offer 1500/6.3. You won't get quality caps higher than 1800 uF in D8 (and those are MB grade with much shorter lifespan).

Otherwise there is a friend of my GF visiting home at Slovakia in a few weeks or so, he may be willing to take those caps to Sydney on the way back, than you can use AU local post…

So I think stand-by rail caps are getting bad in there.

Yes, I had read recently somewhere that if those caps fail, 5VSB can go high. I think the implication was that the PSU would refuse to start. I have seen a couple of posts like this and this pushed me to start investigating and hopefully solving the issue, despite my inexperience.

Do you have ESR meter?

Not yet. I have read lots about them and seen many DIY designs. I would quite enjoy building my own but if I find a reliable chinese ebay dealer I may just get one of the cheap digital ones around the $15 mark. Of course it would be really nice to get one of the Bob Parker 'blue' meters that can be had through Anatek Corp in the USA. A bit expensive now that the $AU is much lower.

If you wish to wait, I have Chemi-Cons KYB 2200/16 being manufactured, I expect them in september or so.

Would they be better to use than RS 3300/16? What price do you plan to sell them for? I was planning to use RS 3300/16 for all 2200 caps irrespective of voltage. I've been playing around with the heatsink on a unit and I can easily bend fins to allow a 30mm length cap to be inserted and then restore the fins.

Those D8x15 6.3V 2200uf are heavy-custom variants ....

Sorry, that was a typo on my part - I had written it on paper correctly but typed it in wrongly. No. 4 should read 1000uf rather than 2200. The 3 D8s are all 1000uf and I was hoping to use KZH (but you only have 42) from your list for the 16V and KZN 1500uf for both 6.3V and 10V since the 6.3V is on the 3.3V rail and the 10V is on the 5V rail. I know it's not ideal but I assume you can get away with a 6.3V cap on the 5V rail?

I will need more than 42 of the KZH 16V D8s but when I look at the PSU, this cap is up against the 12V wires and there is probably enough 'give' in the wires to allow a D10 to be squeezed in there. You have both 16V and 25V KYA D10s in your list so I assume I could use a few of those when I run out of D8s?

Otherwise there is a friend of my GF visiting home at Slovakia in a few weeks or so, he may be willing to take those caps to Sydney on the way back, than you can use AU local post…

Thanks very much for the offer, it is appreciated. Doing things like this for others is always a burden so I'm reluctant to accept. I anticipate ordering around 500+ caps in total so perhaps you could give me an estimate of what the postage from CZ for such a package might be. I would probably rather do that than bother someone else if it's not sky high.

Thanks for your assistance.

It depends on design, old two-transistor designs were dangerous as the voltage could have gone rocket high - but often it still worked - just burned the motherboard. These days the problem is usually that there is very high ripple and often (on the contrary) voltage reads low. Too low for the curcitry to operate (as the stand-by supply usually powers all the operating circuits of the main supply).

I am actually just jumping in the international business with ESR Micro v4.0si (previously I only sold them in CZ/SK). Those are based on the Blue design but lately with more changes, including relay protection so you can hook them into live circuit or to charged capacitors and they will survive without any incident. Can send you some with discount as you already take caps

The KYB have lower ESR than RS and KYA, closer to original Ostor caps in there. Both will work, I have been using RS for years. Worst case scenario is they they may make some noises (buzzing or whistling) under some load values as the cicrcuit is build with some parameters and we will change one…but I have the feeling that with so many machines you won't notice that, it must be pretty loud anyway You can use only RS, or combine with KYA 3300/6.3 as they are slightly cheaper

I use only 6.3V caps without problems. Chinese makers usually opt for 10 V because of bad manufacturing tollerances and 10V ones survive longer. With japanese caps Ifew times went almost to rated value and they work fine up to this day.

The shipping will be aprox.between 500 and 1000 CZK depending on the shipping type (speed, insurance etc.) for such number of caps. So some 30-60 AUD according to actual exchange rate.

BTW what's your username on BOINC?

I got the KYB 2200/16, are you still interested?