Re: Xbox 360 blown caps
No, 820uF is too low. 1800uF 4v would be acceptable. May be pushing it but 1500uF 4v may also work (I wouldn't do it)
mariushm
Badcaps Legend
Last Activity: 07-27-2019, 06:21 PM
Joined: 05-17-2011
Location: Romania
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Re: Xbox 360 blown caps
Replace with electrolytic capacitors that are very low ESR (Panasonic FM/FR , UCC KZE series) or polymer capacitors.
In the case of the capacitors closest to chips (output of VRM) it's safe to use polymer capacitors rated for lower voltage... for example you know the output of a VRM (dc-dc converter) is less than 2v but they've used 6.3v rated electrolytic capacitors for several reasons... you can safely use cheaper 4v rated polymer capacitors with same capacitance or 10-20% less capacitance (ex you could use a 1200uF 4v instead of 1500uF 6.3v if 1500uF...Last edited by mariushm; 07-24-2019, 05:14 AM.Leave a comment:
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Re: Question about SMD Crystal and proper capacitor placement / pin connections
He uploaded this:
I can't figure out the traces... there's 3 traces popping out of that 10uF ceramic capacitor footprint. Like I said... best to have one single trace come out and then branch out traces from that trace.
...and makes no sense to have notation there 0.33uF ... also if you have one regulator powered from another, then the decoupling capacitor (0.1uF ) for that second regulator can be omitted, because you already have an output capacitor on the output of...Last edited by mariushm; 07-18-2019, 01:23 PM.Leave a comment:
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Re: Question about SMD Crystal and proper capacitor placement / pin connections
What the hell are you doing with that 7812 linear regulator?
How are you connecting those middle pins and the tab, those are typically Vout ... you can't just wire them like that.
Why don't you try recreating your circuit in DipTrace, it's free for up to 300 pins so your project should be doable in it? Here's link : [url]https://diptrace.com/download/download-diptrace/[/url]Re: Question about SMD Crystal and p...r /> What theLeave a comment:
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Re: Question about SMD Crystal and proper capacitor placement / pin connections
You can use ceramic capacitors on the output but add a tiny resistor in series with the capacitor to increase the ESR. For example, add a 0.47.. 0.68 ohm resistor (anything above 0.1 ohm, but below 1 ohm).
Alternatively use an electrolytic capacitor, as those by default will have at least 0.5 ohm ESR in such low capacitance values.
Tantalum capacitors are suggested in datasheets because by default 10-22uF tantalums typically have around 0.15..0.4 ohm esr but they're expensive...Last edited by mariushm; 07-16-2019, 04:18 AM.Leave a comment:
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Re: Question about SMD Crystal and proper capacitor placement / pin connections
According to this page : [url]https://bbs.espressif.com/viewtopic.php?t=133[/url]
.. and ESP8266 consumes up to 170mA of current when transmitting. Also, another page says the start up current can be up to 320mA ... so I guess you need at least around 400mA.
Yeah, i guess you need at least something like 500mA for the 5v regulator.
Anyway... looking at your circuit boards... what else I can suggest is
* move the 3.3v ldo on the top side of the pcb... plenty...Leave a comment:
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Re: Motherboard schematics archive?
See previous page, or [url]https://www.badcaps.net/forum/showpost.php?p=897834&postcount=214[/url]
tldr : had to cancel dedicated server that hosted the files, will be unavailable for some time. I'll try to get the contents back soon.Re: Motherboard schematics archive?<... contents backLeave a comment:
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Re: Motherboard schematics archive?
See previous page, or [url]https://www.badcaps.net/forum/showpost.php?p=897834&postcount=214[/url]
tldr : had to cancel dedicated server that hosted the files, will be unavailable for some time. I'll try to get the contents back soon.Re: Motherboard schematics archive?<... contents backLeave a comment:
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Re: Step-Down Buck Charging Board XL4015 ADJ Lithium Battery Charger Converter Module
Those don't really have anything to do with lithium battery charging, it's just a regular buck converter, a dc-dc converter.
No, as it is, it can't do 5A. Heatsinks would have to be applied. But it will also depend on your input and output ... the smaller the differential, the more efficient this will be... if you do 5v -> 4.2v then it will do... if you do 24v->4.2v ... tough.
It may do 3A continuously in any condition.
It's like cars have up to 100...Last edited by mariushm; 07-14-2019, 08:24 PM.Leave a comment:
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Re: Help with capacitor substitution for a DVR
I sincerely doubt you need so high end capacitors.
Most likely it was some overstock capacitors they had, or someone used them instead of other capacitors.
I mean, you typically need these ultra low ESR capacitors to be soldered as close as possible to the circuit board, as close as possible to the switching regulator IC or transformers to keep the current loop as small as possible.
Leaving such long leads on those capacitors kind of defeats the purpose, the extra wire length adds resistance and a very tiny amount...Leave a comment:
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Re: Adhesive to Hold on LED Strips?
Problem is you don't know how well those tapes transfer heat into the metal back side of the lcd/tv panel ... the led strips probably use the back metal to spread led heat.
You can use thermal pads or sheets, here's a starting point (selected only ones with adhesive on both sides) : [url]https://www.digikey.com/short/p95d7h[/url]
An example:
26$ for 640 mm x 320 mm : [url]https://www.digikey.com/product-detail/en/t-global-technology/LI98-640-320-0.15-0/1168-1359-ND/3042188[/url]
15$ for 320...Last edited by mariushm; 07-13-2019, 12:19 PM.Leave a comment:
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Re: First Timer - Mystery capacitor identification
You can use a 6.3v rated polymer capacitor instead..
Cap filters 5v or 3.3v from psu.. they probably used 10v rated for better specs or because there was room (same diameter for 6.3v or 10v).
took liberty of filtering list: [url]https://www.digikey.com/short/p95twp[/url]
All 820..1200 uF 6.3v or 10v polymer caps in 8mm diameter, in stockRe: First Timer - Mystery capacitor ... they probablyLeave a comment:
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Re: Question about SMD Crystal and proper capacitor placement / pin connections
I intentionally avoided 1117 regulators because majority of them can be unstable with low esr ceramic capacitors.
Original 1117 LDO required esr on output between 0.1 ohm and 1 ohm...
Some datasheets don't say it but example circuits show either tantalum or electrolytic caps (both typically above 0.1 ohm esr in low capacitance)
Some datasheets say stable with ceramic caps but then recommend adding a 0.15..0.47ohm resistor in series with output cap. or something like that.
...Leave a comment:
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Re: Question about SMD Crystal and proper capacitor placement / pin connections
It looks like WAY TOO FAR from the chip when there's lots of room around the chip to place the oscillator closer.
Also, no input and output capacitors on the 7805? Stick a 0.1uF ceramic close to the input of the 7805 and optionally a 1-10uF ceramic on output.
Why the DPAK 7805 ... is your board really using 500mA+ of current? Why not use a SOT223 or something similar
You could use for example
AP7370 : [url]https://www.digikey.com/product-detail/en/diodes-incorporated/AP7370-50W5-7/AP7370-50W5-7DICT-ND/10235831[/url]...Leave a comment:
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Re: Cable Modem Repair - Why Do They Fail?
Why they fail so often...
Companies want cheap stuff to "lease" it to customers (give it for "free" aka paying a few dollars each month for it)
Companies don't need very long life because they know 3-5 years from now there's gonna be a new version of some cable standard (ex from DOCSIS 2 to DOCSIS 3), or something new pops up (like from HD to 4K and HDR, so set top box needs HEVC support or HDCP 2.x support), or they can market a newer version of the set top box for a dollar more
The...Leave a comment:
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Re: Zero to Expert in pcb design
Nobody does that, because nothing's smart enough to automatically figure out the number of layers a PCB has, and x-ray capability to figure out traces within internal layers.
Also, big components like transformers or inductors or even electrolytic capacitors can hide traces under their footprints making traces undetectable.Leave a comment:
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Re: Asus GTX 980ti Matrix capacitor
It's a polymer capacitor, so the ESR will be very small. The video card receives 12v and 3.3v through the pci-e slot and pci-e power connectors.
The capacitance being so low at 150uF, I would suspect that capacitor is on the 12v input voltage, so it's most likely rated for 16v or 25v.
However, that stylized j makes me think it may be a 6.3v polymer, because these are common letters used to mark voltage on surface mount capacitors:
Letter Voltage
e 2.5
G 4
J 6.3
A 10
C 16
D 20
...Leave a comment:
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Re: Capacitor replacement
Have to agree, the small one may not be able to handle the current.
Look into capacitors rated for higher voltage, like for example 35v..63v.. the higher volume will give them the ability to handle higher current bursts.Leave a comment:
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Re: Nippon Chemi-Con 3300uF 10x25mm?
I sincerely doubt it. You should be fine with KZE.
Also keep in mind if they're for 3.3v and 5v output filtering, you'll be fine with 6.3v rated KZE (or FM) which will have slightly higher esr... datasheet says 22mOhm for 2200/6.3vLeave a comment:
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Re: Zero to Expert in pcb design
Depends on your needs. For some niches some tools are better than others.
For simple boards, KiCad, DipTrace, even Eagle could be good enough.
For more complex stuff, there's other players in the market like Zuken (Sony likes them) or PADS from Mentor, or Orcad ...Leave a comment:
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