not lost, save the old ones.
cap noob duh
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Last Activity: 03-26-2010, 06:01 PM
Joined: 01-29-2010
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Re: Need help whith choosing right caps
not lost, save the old ones.
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Re: K3405 mosfet pdf
also, is there a key, for a desktop computer, to hold before power on, to start/force anything?
- just cause some older laptops had that, ibm thinkpad i think.Leave a comment:
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Re: K3405 mosfet pdf
really hoping for some feedbackLeave a comment:
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Re: K3405 mosfet pdf
Oh,
I've checked with and without the following hooked up:
floppy
HDD
CD
video card
memory
cpu(fan plugged in, ofcourse)Leave a comment:
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Re: Suitable replacement for Nichicon HM series?
I'd add that my Vantec van-420a psu was also a mobo killer, full of fuhjiyoohoo's.
- I recapped it, and even this dell is being run by it.Leave a comment:
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Re: K3405 mosfet pdf
removed all caps, checked capacitance with mmeter, replaced all with a nice 55w iron I found(Imperial pencil), still a no go.
- no video & HDD light always on, no floppy activity to do the auto-bios-flash at boot time.(new floppy, tested in this computer.)
- checked for voltage on all caps, seems ok.(just some odd voltages i wasn't ready to see, like: 3.7v, when others do have the 3.33v)
- 2 of the vrm chips have 0v on one leg, 7v on another, but a normal 4.85 on the tab/middle leg.
Looks like I missed the boat on saving...Leave a comment:
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Re: K3405 mosfet pdf
Well, got my caps.
redid psu and mobo.(used gun on mobo, not fun, but no damage.)
fans spin now but no pic and HDD light always on.(had light problem once before on a system.)
- all hardware is good, system ran fine till it just wouldn't turn on anymore.
- voltages look fine.
will take out mobo and triple check for shorts, oh and must do wiggle test first, incase a cap leg didn't get solder right.
(on psu which used normal solder, using the sucker before taking cap out made a nice clean hole.)
added: did...Last edited by cap noob duh; 02-12-2010, 11:06 PM.Leave a comment:
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Re: K3405 mosfet pdf
double good news today, this is nice.
so I should be getting new caps soon for psu and mobo(original computer) and
with lower required specs for a psu, i can hold off on stocking for the dell psu and get them local.
it has been a pleasure, and thank you so much 370forlife !!
(i'm gonna keep reading and learning, it's the only thing i've been missing in my computer-help skills. After that it'll be on to mosfet checking, cause who knows, i may find a blown one in the original computer. hehe)Leave a comment:
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Re: K3405 mosfet pdf
cool !
I'm much less concerned now, plus
did more reading at:
[url]http://techtrain.microchip.com/webseminars/Archived.aspx[/url]
- so far i've read, get low ESR and High ripple.(and thats' in the 'effects of components in smps' seminar.
(may not be referencing setup and test parameters yet.)
and found a list of supposed true manufacturers:
[url]http://whirlpool.net.au/wiki/?tag=PSU_Manufacturers[/url]
the dell has Ltec caps and one green one i can't see the name of, but not sanyo...Leave a comment:
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Re: K3405 mosfet pdf
psu is: [url]http://www.vantecusa.com/front/product/pro_list/42[/url]
I'll do some for googling on it, and if it turns up as 'critical' on enough sites,(design spec links would be great) i'll be relying on local caps.(I live in a big city though)
I already have an account going with badcaps.net and shipping does not make a couple of caps worth it, from any supplier.
- also the local stuff is good enough at 0.045 ESR ratings.
I may also wait for the dell supply to show signs of strain before redoing it, if the ESR is...Leave a comment:
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Re: K3405 mosfet pdf
I've read that leaving long leads on capacitors can increase ESR, some say it isn't enough to worry about, when trying to keep ESR low.
I have the space, would long leads help? insulating them is easy with bits of insulation from skinned 16 gauge wire.Leave a comment:
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Re: K3405 mosfet pdf
nah, the Fuhjyyu caps I can only find ESR for the TMR type, and most are TNR
[url]http://www.fuhjyyu.com.tw/pro.htm[/url]
as for Rubycon, they have sent that section to Sun Elec. and they don't have any info.
Cross fingers and pray? lol yeeesh.
when you say ripple will increase, how bad are we talking?
the TMR 2200 uf @ 10v is listed at 0.039 ESR,
and the Samxon GC are listed @ 0.009 ESR,
and I bought Rubycon MCZ, oh man.
(ding, light came on,,, now I know what the poster meant when...Leave a comment:
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Re: K3405 mosfet pdf
oops and oh and thank you.
I just ordered MCZ and GC for the power supply...
I'll have to check specs now on the old ones.
- 5 of 11 were bust, so I had to remove them anyways.
i'm guessing the cable length from mobo to psu is enough to negate the effects of the better quality caps, as seen by the psu; re: the tuning.
so much to learn, so little beer...
I may be stuck with the caps i've ordered though, hope it don't go boom!Leave a comment:
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Re: K3405 mosfet pdf
the terminology i was missing was Linear vs. SMPS(switched).
my power supply:
it is SMPS with active PF. cool.
it kinda failed on the 140,000 hrs. life though. hehe
so, due to its being a switched psu, I could experiment with polymers in it, one day; if all is well understood by me.Leave a comment:
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Re: K3405 mosfet pdf
cool, ty.Leave a comment:
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Re: K3405 mosfet pdf
added:
Thanks for the reply, and I assume you mean the mod is for after cpu vrm only.
I think my confusion was with the electrolyte and polymer choices.
Is it possible that electrolyte replacements were offered at the start of this huge cap problem because polymers just weren't available? or, because no-one had yet done any polymer-replacement testing?
as for the frequency, i've poked around these pdf's:
[url]http://www.irf.com/technical-info/papers.html[/url]
- in the DC-DC section
and found that...Last edited by cap noob duh; 02-03-2010, 01:55 PM.Leave a comment:
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Re: or is it: precapping your psu?
the 85c cap is on the top right corner of cpu, and
is beside the cpu_fan plug.
220 uf @ 16v 6mm 85c (12v fan)
- same as the 5 identical ones around the usb's.
(but they are closer to the pci-e than the cpu, and lower down.)Leave a comment:
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Re: K3405 mosfet pdf
although, my last post does not explain all the 'big' caps on the dell.
- why so many?
- why not ANY on some of the new boards?Leave a comment:
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Re: K3405 mosfet pdf
Think I got it.
K3405 switching times mentioned in nano seconds, so it can 'move'.
and the Bulk capacitors are just to balance,
and there must be a bunch of surface mount polymer / high-frequency caps.Leave a comment:
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Re: K3405 mosfet pdf
found a nice writeup on VRD / VRM
[url]https://cdn.badcaps-static.com/pdfs/ce4338a8cdc323a72a40a7ea4b1f54da.pdf[/url]Re: K3405 mosfet pdf<br /> <br /> ...54da.pdf[/url]Leave a comment:
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