How can I test them on pcb?
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Re: SMD capacitors?
You test them the same as other caps.
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Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
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Re: SMD capacitors?
capacitance meters are designed to test on board...they use low AC frequency
if I remember correctly
of course to be absolutely sure it best to remove, but SMD is a bit of a pain
so best is "If in doubt replace"
(if you dont have proper removal tool 2 irons can do the job)
larger electrolytic type tantalum ones are prone to failure (+ on them in uf range)
smaller ceramic types will mostly probably be ok
but all caps can fail
(and there has be cases of them cracking there ends off due to stress)
welcome & cheers
You step into the Road, and if you don't keep your feet, there is no knowing where you may be swept off to." Bilbo Baggins ...Comment
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Re: SMD capacitors?
Can I get some recommedations for a good Capacitance meter?
I have a Extech RC100 SMD capacitance meter which is totally unreliable
for in circuit measuring (works fine outside circuit with smd capacitors)
Thanks
Last edited by dds; 02-22-2008, 10:28 AM.Comment
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Re: SMD capacitors?
SMD are measured the same as other caps.
If it's in the circuit and there are other caps in parallel either directly or indirectly then in-circuit testing won't work.
- There are usually other capacitances in parallel in-circuit.
That's probably what your problem has been.
Not the meter.
.Mann-Made Global Warming.
- We should be more concerned about the Intellectual Climate.
-
Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
- Dr Seuss
-
You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
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Comment
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Re: SMD capacitors?
Thanks for your reply. But I'm more confused, how can I reliable measure capacitance in circuit?Originally posted by PCBONEZComment
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Re: SMD capacitors?
I don't know what you don't understand.
If there is nothing in parallel then you put a lead on each end and measure it.
If there is something in parallel you remove at least one end from the circuit and do the same thing.
.Mann-Made Global Warming.
- We should be more concerned about the Intellectual Climate.
-
Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
- Dr Seuss
-
You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
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Hello
I have a big problem and that is that in some cases when repairing active pfc power supplies I cannot work with a test lamp. I can only get help with 5 volts standby and for starting and starting I have to work without a lamp and this way there is a possibility of parts exploding and other parts being added.
Sometimes with a multimeter test the problems can be reduced to some extent, but I had several cases that had to be tested on and online and recently two varistors exploded. They had terrible resistance because the power supplies were over 800 watts.
Is there a way... -
Hello.
GPU came in, green lines. Spent lots of time using to get the Mats / mods drive working (found on youtube).
Found issue with a RAM block
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Trying to test again, assuming getting the false positive. Originally had over 1K on a single bank. Now getting tosses low between banks.
Used a good card to test and same results low errors 32+.
I am just search for some form of command to do a full test on the GPU.
I just ran the mats command with my good GPU and passed after roughly 40 min.
The repaired one, ran... -
hey all, iv got my favourite battery charger here which iv had for many years probably 15 years now or maybe even more. it still works good but thought id open it up to clean the dust out of it, lots of dust inside but now its clean and noticed 4 capacitors inside it and wondered if i should replace them.
it has inside:
2 x 47uf 16v caps 105c branded as Su'scon (lol sounds sus to me)
2 x 470uf 16v LZ105c branded as G.Luxon
not heard of these brands are they any good?
iv attached photos of the charger and the board inside for an idea on the type of... -
Hi, I have some 32 bits computer motherboards that need repair, as they fail to
power on.
Here are some examples :
(N.B. "capacitors" indicated here are electrolytic capacitors located in the onboard
switching supply area).
(N.B. #2 : I could not find a 3300 microF aluminum-polymer with a higher voltage
than 6.3 V.)
1 - Motherboard #1 : this is an Asrock K7VT2 (socket A) that still works well. To put it on test
I replaced capacitors with aluminum-polymer.
3300 microF/6.3 V. x 4 replaced by 3300 microF/6.3 V. (KYOCERA... -
I did not have any 27uf @ 50 volt capacitors but one nice thing is that it has enough room for two capacitors in parallel a 22uf and a 4.7uf @ 50 volts 22 plus 4.7 equals 26.7uf which so very close to 27uf I will show some pictures of it sometime tomorrow
This is one of the shit est boards I seen in a very long time and it was the daughter board the traces just lifting off the board I had to use the capacitor leads to repair the the traces and the main board is not any better because I had to repair several traces for the daughter board to the main board
After all of...
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