Channel Well CWT-450BDP

[JEWilson]

Hi

This PSU had the ATX 2x10 pin replaced
Have tested it with two types of PSU tester (for what that's worth) and
everything appears to be ok.

I did open it up to see if ok. Seems no problems apparent.
What are the views of forum members - are these any good?

Thanks

[linuxguru]

Re: Channel Well CWT-450BDP

Channel-Well usually has Fuhjyyu caps, and they're among the bad brands. If it hasn't already failed, it will fail, usually sooner than later. However, they should be OK if you replace the caps with the recommended Japanese replacements.

[Spacedye69]

Re: Channel Well CWT-450BDP

Why was the ATX connector replaced? If it was burned or melted, I would check/replace the caps before plugging it in to anything too important.

[Oklahoma Wolf]

Re: Channel Well CWT-450BDP

This unit is pretty much the same as the Antec SL450, though if memory serves the P indicates it has active PFC. Eventually, it will have problems with those Fuhjyyu caps - CWT builds of this era rarely escape the issue.

[JEWilson]

Re: Channel Well CWT-450BDP

Y - twas burnt on two pins on the ATX 2x10 plug

I will be replacing the output filter caps as a matter of course
Thanks for the input.

My enquries were simply to establish whether (not) it would be useful
to keep or put in a box for my bothers kids

Err.... will be opting for the latter option

Thanks

[JEWilson]

Re: Channel Well CWT-450BDP

Ok, after a further inspection, I have found;

Electrolytics Only

In the primary;

2 of Black 470 uF 200 V CapXon 85 deg C - H 25.4 mm x Dia 25.4 mm
1 of Black 10 uF 50 V Unknown KM 85 deg C - H 10 mm x Dia 8 mm

In the switcher;

1 of Black 22 uF 50 V Fuhjyyu TNR 105 deg C - H 10 mm x Dia 5 mm
1 of Black 17 uF 25 V Fuhjyyu TNR 105 deg C - H 10 mm x Dia 5 mm

In the output filter;

2 of Black 1 uF 50 V Fuhjyyu TNR 105 deg C - H 8 mm x Dia 3 mm
2 of Black 10 uF 50 V Fuhjyyu TNR 105 deg C - H 10 mm x Dia 5 mm
1 of Black 820 uF 16 V Fuhjyyu TNR 105 deg C - H 20 mm x Dia 8 mm
1 of Black 3300 uF 6.3 V Fuhjyyu TNR 105 deg C - H 33 mm x Dia 8 mm
1 of Black 3300 uF 10 V Fuhjyyu TNR 105 deg C - H 25.4 mm x Dia 8 mm
1 of Black 3300 uF 16 V Fuhjyyu TNR 105 deg C - H 30 mm x Dia 8 mm
2 of Blue/Purple 1000 uF 10 V Fuhjyyu TMR 105 deg C - H 20 mm x Dia 8 mm
1 of Blue/Purple 2200 uF 16 V Fuhjyyu TMR 105 deg C - H 30 mm x Dia 8 mm
1 of Blue/Purple 4700 uF 10 V Fuhjyyu TMR 105 deg C - H 38 mm x Dia 10 mm

1 of Black 330 uF 16 V CapXon deg C - H 20 mm x Dia 5 mm
1 of Green 1 uF 50 V CapXon deg C - H 8 mm x Dia 3 mm

The rest as far as can I determine, are bead type caps

What are the recommendations for replacements excepting
obviously they require to be 105 deg C and the same can sizes (where or if possible)?

Thanks for your consideration

[Super Nade]

Re: Channel Well CWT-450BDP

Holy hell man, replace everything! That is a time bomb waiting to explode.

My choices would be:

Nippon Chemicon KMQ on the Primary.
United Chemicon KY, LXY and KMG everywhere else.

I'm recapping a similar unit. A small, quick and dirty blurb I wrote for overclockers.com should be up by the end of the week.

[linuxguru]

Re: Channel Well CWT-450BDP

It's sufficient to replace everything over 470uF - the smaller caps usually don't fail or aren't critical. The one exception to this rule could be the 47uF/25v or the 22uF/50v on the primary side, depending on the topology/location. If it's right next to the auxiliary transformer and is being directly charged by a fat (1A to 3A) fast-recovery rectifier from the auxiliary flyback transformer, that cap needs to be replaced too - it can't handle high flyback ripple currents for too long. Something like a 100uF,35v NCC LXA/LXF/LXJ/LXV/LXY/LXZ should be OK there.

[JEWilson]

Re: Channel Well CWT-450BDP

Got round to replacing the caps in the O/P filter of this PSU.

I have been able to squeeze in the new Panasonic FCs with the
exception of the 4700uF 10V which I seem able to get only in 12.5mm dia.

I have had a look around for a cap of this value with a 10mm dia., can't
seem to source any.

What do members recommend?

There is no way the 12.5mm dia. FC will squeeze in there... argh!

[gonzo0815]

Re: Channel Well CWT-450BDP

Replace with a 4700uf 6.3v or 3300uF 6.3v. May be Big Pope can supply you that a large cap in 10mm.

4700uf 10mm is simply not a standard value and you probably won`t get it from any other source in small quantity.

[Big Pope]

Re: Channel Well CWT-450BDP

Replace with a 4700uf 6.3v or 3300uF 6.3v. May be Big Pope can supply you that a large cap in 10mm.

4700uf 10mm is simply not a standard value and you probably won`t get it from any other source in small quantity.

Agree, i haven't seen any 4700uF 6.3V/10V in diameter 10mm for reputation brands. There is also very rare for 3300uF 10V/16V in diamter 10mm, we can't source it from the market, except custom made.

Recently, i have ordered some custom made 3300uF 10V/16V in D10 x 30mm (Samxon RS Series) for power supplys. Please contact me if anyone want to try outside US/Canada. If you are in US/Canada, please contact Top Cat (owner of this forum) directly.

[JEWilson]

Re: Channel Well CWT-450BDP

Ok

I do have a Panasonic FC 3300uF 10V in 10mm

I will try that first

[JEWilson]

Re: Channel Well CWT-450BDP

OK

Recap done and tests with the go/no-go tester appear ok
Next thing to do is to repair the 20-pin ATX connector

What tools do I need?

Simple thing to do would be get a new ATX connector and
crimp tool.

Where could I get these?
Would anything else be required?

Please advise

Thanks

[PCBONEZ]

Re: Channel Well CWT-450BDP

I'm working on a different PSU but it also has the 4700uF 10v TMR Fuhjyyu craps.
They are rated (supposedly) for 1580 ripple and .038 ESR.
-
I'm replacing with 3300uF 6.3v MBZ at 10mm
The MBZ's ripple is 2800 and ESR is .012
They should more than handle it even with the reduced uF.
[And they fit.]

.

[starfury1]

Re: Channel Well CWT-450BDP

Just stating the obvious here really I suppose

Humm well from posts I read PCBONEZ I suppose its possible the FU's are @ those values used, to compensate for being crap.

As you well know the cap uf is nominal anyway by 10's of %
So yeah using somewhat near the same but better quality caps should equate to around the same (if not in some respects better) operation.
(although that little extra capacitance doesn't go astray)
sure there might be slight degradation but doubt it would be much to worry about unless you are possibly driving it really hard

Are you intending to do some load testing measurements on it?

keep us posted on how it goes anyway PCBONEZ

Cheers

[PCBONEZ]

Re: Channel Well CWT-450BDP

Oh come on.
The 4700uF is a bogus value.
Even 3300uF is over-kill.
Someone in here recently pulled some 4700uF Fuhjyyu and measured them at something like 1300uF.

In most PSUs you see 1000uF to 2200uF caps in those positions on those rails and a lot of the time they are single caps not two in parallel.

If you borrow the formula from the AMD and Intel design guides for bulk capacitance and ESR, use the typical 2 usec, the full amps on the rail, and .050v for the transient, and the supposed ESR for the Fuhjyyus then it comes out to anything more than 1625uF on the 5v and more than 1296uF on the 3.3v is adequate. With the lower ESR of the Rubycons it needs even less capacitance. - I know that's not what that formula is in the guide for but in this situation it's calculating the same thing so it works.

.

[PCBONEZ]

Re: Channel Well CWT-450BDP

That's for the PSU I am working on which is 40 amps on the 5v and 32 amps on the 3.3v.
-
It will be a while to get results. Still have to order some of the caps for it (them) and they aren't not on the hot projects list just yet.

[JEWilson]

Re: Channel Well CWT-450BDP

Whereas PCBonez has made a vaild point, the matter of cap replacement
(for me) is simply attemting to accomodate the requirements of end users.

So far as a user may opt for a recap;

As rule of thumb, try to replace badcaps with better at an equivalent
value. There are, of course, problems here so far as acommodating
the can size of better caps at the same value is not problem free.

Yes, I have been advised given such circumstances as above, to
use a preferred brand at a smaller rating. Even so, end users
tend to figure for the money they are paying - it's like for
like in the capacitor stakes and do not immediately grasp (even
when shown) the difference between a Panasonic FC 4700uF 10V
and a 4700 uF 10 V Fuhjyyu TMR.

But fora such as these do definetly help in that regard

[PCBONEZ]

Re: Channel Well CWT-450BDP

JEWilson

Exactly.
When ever possible use the same specs or better as the original:
Same uF or a bit higher if you must.
Same volts or a bit higher if you must.
At least as much ripple capacity.
Same ESR or lower.


I stick to that when ever possible but there are times that won't work.
- No data for the old caps.
- No replacement caps exist from a reliable manufacturer.
- The existing caps are not original and are wrong.

In these cases you have to look at what is typically found in that application in other similar equipment and maybe do a little math.

The PCB I'm working on has 2 x 10mm in parallel on each the 5v and 3.3v outputs with zero room for larger diameter caps. [I could probably FORCE 12.5mm in there but there would be zero airflow around the caps, crimped wires, and a good possibility of creating a ground.]
Unfortunately good brands in 10mm over 3300uF do not exist.

The options are:
- Mount larger caps remotely and run wires to the PCB. (Not likely.)
- Use the best 3300uF 10mm caps I can find. <- chosen path.
- Use a single cap in place of the pair (they are in parallel) that matches the combined ratings of the pair. (I looked.) To get there at 2x4700uF(min) and the combined Ripple capacity and ESR I'd have to go to a 16mm 10,000uF cap in HE or better. One 16mm -might- fit but I can't be sure.
- Use a 12.5mm and an 8mm in parallel. Might work but I'm concerned the mismatch will cause the bulk of the load to shift to one cap an overheat it.

.