Not everyone reads every word of a EULA. But there's always somebody who wants to speak for everybody. Even when they don't have two cents.
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a23d56
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Last Activity: 06-29-2014, 05:39 PM
Joined: 04-20-2011
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Re: the gutless, bloated, and fried power supply hall of shame
Not everyone reads every word of a EULA. But there's always somebody who wants to speak for everybody. Even when they don't have two cents.
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Re: the gutless, bloated, and fried power supply hall of shame
No pics, just my 2 cents.
When ordering a few computer items from cwc-group, and I noticed they had a 450w power supply for $15. Yeah I know. But I needed an extra for testing, and I was already paying shipping for the other items, so I thought why not. I hooked it up to a test board, shorted the power pins on the motherboard, and about two seconds later, POP! Ugh. I never tried fixing a power supply before, but with some experience recapping motherboards, I thought why not open it up and look. I know...Last edited by a23d56; 06-12-2014, 10:50 AM.Leave a comment:
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Re: no post Pcchips T18 after recapping
Never had a PCChips T18, but I've worked on several M810.
When I got them, all would POST, but ran unstable (freeze). Replaced all caps, even small ones, on 1st board. It's stable now, tested with WinXP, linux, and NetBSD.
Seemed like a good start, so I replaced all caps on 2nd board too. Now it won't POST. Bah! OK, 3rd board, replaced about half the caps. Now it won't POST either. Double Bah! So of three boards, I fixed one and killed two. Maybe too much flexing and stress on the BGA solder balls? Dunno. Working...Leave a comment:
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Re: Motherboard low ESR vs general purpose
Learning how to fix things requires effort. All that hot new tech you buy this year will be "obsolete" (from your viewpoint) in two or three more years.
Once I figured out that hot new tech is a never ending treadmill, I stopped wasting money on it. Now I get old stuff for little or nothing (cause nobody else wants it now) and fix it up. Saves money, and it's more fun.
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Re: Motherboard low ESR vs general purpose
I never considered working with surface mount components until I watched a Dave Jones youtube tutorial where he does some surface mount soldering and says "even Stevie Wonder could do this!" I really didn't know what I was doing, but that's never stopped me before.
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Re: Motherboard low ESR vs general purpose
I replaced the small caps too, but the problem remained. Then I looked at the circuit, mostly surface mount, tiny components. With no electronics training, it's over my head. But I do know enough to see the battery +ve goes to a 1k resistor. That checked OK. Next stop is a tiny 3 leg thing marked "352." Googling and reading data sheets led me to believe it's a P channel mosfet. If true, my multimeter indicated a short from source to gate.
I found a replacement part at Mouser and ordered a few. It seemed crazy to try...Last edited by a23d56; 05-21-2014, 07:23 PM.Leave a comment:
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Re: Ultrasonic cleaning pcb's with caps still on board
I use MAX contact cleaner (nozzle spray can) on motherboards. Dries fast.Leave a comment:
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Re: Motherboard low ESR vs general purpose
I have two of these boards, identical, from the same source. The second board, I've not done any work to yet. Funny thing about the second board is, it will not retain CMOS settings even with a good battery. And it seems to drain a battery if I leave it in.
There are a couple of small caps near the CMOS battery, so I think I will try replacing them and see if that helps. Looks like Mouser has a good deal on Kemets if I buy quantity 50....Leave a comment:
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Re: Motherboard low ESR vs general purpose
The small ones on this board are Luxons. Are they cheapo?...Leave a comment:
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Re: Motherboard low ESR vs general purpose
I thought of getting an ESR tester to check them, but then I read you can't reliably test them in circuit. If I take them out, I'll replace them while I'm at it.
But you're saying small caps are less likely to fail?
Why?...Leave a comment:
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Motherboard low ESR vs general purpose
I have an old PCChips M810L motherboard.
I bought low ESR caps to replace all the big caps (1000uF and up), did that job, and the board is running OK. I haven't replaced any small caps yet, there are about 30 in all, a mix of 16v 100uF and 25v 22uF.
Just wondering if I can get by with general purpose caps for the small ones, since they are cheaper. I understand you want low ESR near the power supply, but is that necessary for all caps on a motherboard?
It's not like I'm going to sell this thing to a hospital for a life critical application. I'm just... -
Re: Made in USA
True, if you want the ends squared off like they come from the factory. But once the board is in the case, the little pointy ends won't hurt me.
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Made in USA
I have an old pair of small diagonal cutters that I wore out. I started shopping for a new pair and found these for $7:
[url]http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1086973&CatId=1798[/url]
and these for $25
[url]http://www.amazon.com/Klein-D257-4C-Electronics-Standard-Diagonal-Cutting/dp/accessories/B000ARQ5GG[/url]
I would like to have the Klein (made in USA, induction hardened) but it's hard to justify an extra $18 for the light use I will give them.
I also thought of buying a weller... -
Re: My Ultimate(?) "Which Soldering Iron" Thread
If you do big heavy boards you may as well put some money into good tools. But I'm only doing some regular consumer boards. My radio shack 40 watt iron and 45 watt desolder tool have worked so far.
BTW, I wrote in another thread that I used my iron and compressed air to blow out the holes. Worked good, but I got curious about the contents of the can. Seems most canned air is diflourethane, which is flammable.
[url]http://en.wikipedia.org/wiki/Gas_duster[/url]
Probably...Leave a comment:
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Re: kzg / ost
OK. At least I know what my options are now. I may pull out the 5 polymers too, next time I heat up my iron. Thanks for following this to the end.
The end. Again.Leave a comment:
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Re: kzg / ost
Hmm, I see you mentioned 560uf poly caps. So my wild guess would be, the 560 marking on mine means 560uf.
If I understand what you've said: the ripple goes through the 5 low ESR / high ripple polys. The designer uses 5 electrolytics, to keep the cost down. No need to overbuild.
So I should be able to raise ESR somewhat on my 5 electrolytics, as long as I have enough total uF in the circuit. Sounds like the 5 cheap Nichicon HM 1000uF electrolytics I have in mind, will do the trick.
The end (I think).
:beer...Leave a comment:
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Re: kzg / ost
I don't know what they are, but they look exactly like the ones in your picture, with similar blue streaks on the tops. I guess they're polymers. The only markings I can read are on the tops:
NA
560
g
343
I don't see any markings on the sides....Leave a comment:
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Re: kzg / ost
Never considered that till now, but looking at a data sheet on Mouser
[url]https://cdn.badcaps-static.com/pdfs/88769c3fed2ebede166ccb04935704c7.pdf[/url]
ESR is lower and ripple is higher than electrolytics. Is that why they work? Is lower ESR always better? Why would they mix and match polymers and elcectrolytics on the Intel D865perl VRM if they cost about the same?Re: kzg / ost<br /> <br /> <br /> ...04c7.pdf[/url]...Leave a comment:
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Re: kzg / ost
Yes I was looking at that data sheet, but there was no 8x20 can size for the 820uf 6.3v. So I thought that meant my caps were some old version no longer made, and the old data sheet for them was no longer available.
But now I remember pcbonez said, find the same can size somewhere else in the series, because ESR and ripple are the same for any given can size within the series. OK, I got it now. I'm no EE, I just know enough to be dangerous ...
So that means the caps I removed had ESR=.012 ripple=2220.
And...Leave a comment:
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Re: kzg / ost
I don't have a camera, but my board is just like the one in your picture with the yellow circle. I removed the 5 tall ones (they were bulged), and left the 5 short ones intact. The 5 tall ones I removed were Nichicon HN 820uf 6.3v 8x20mm.
I can't find any data sheet for the caps I removed, so I don't know what their ESR was. In the other thread, you said
OK. But I'm looking at that Panasonic .065 ESR and wondering, why can't I use a cheap Nichicon HM that has better specs:
UHM1A102MPD6TD 1000uf...Leave a comment:
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