Badcaps.net Forum
Go Back   Badcaps Forums > Battling the Bad Capacitors > General Capacitor Questions & Issues
Register FAQ Members List Social Groups Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 07-26-2012, 12:58 PM   #1
Cornboats
Dave
 
Join Date: Oct 2010
City & State: Worcestershire
My Country: United Kingdom
Line Voltage: 240v 50HZ
I'm a: Knowledge Seeker
Posts: 61
Thumbs up Smd electrolytic capacitor identification

I'm working on a LG Ysus board at the moment. Can anyone help me interpret the markings so I can buy replacements.

The first capacitor is written;
45
33
25F

Capacitor meter reading gives this at 31 MF so I'm guessing thats the middle number but whats the operating voltage?


The second is written
72205
220
25F

Capacitor meter gives this at 209 MF so I'm guessing thats the middle number but again whats the operating voltage?

Does anybody have a smd electrolytic capacitor supplier?
Cornboats is offline   Reply With Quote
Old 07-26-2012, 01:07 PM   #2
selldoor
Slow Learner
 
Join Date: Dec 2010
City & State: Lancashire UK
Posts: 6,953
Default Re: Smd electrolytic capacitor identification

Might be useful if you posted pictures as all manufacturers use a different coding.

"Does anybody have a smd electrolytic capacitor supplier?"

Might be useful if you updated your profile with the country and mains voltage.

Readers could be in Australia or Croatia but it might be of little help to you where they get there caps?
selldoor is offline   Reply With Quote
Old 07-27-2012, 11:19 AM   #3
Cornboats
Dave
 
Join Date: Oct 2010
City & State: Worcestershire
My Country: United Kingdom
Line Voltage: 240v 50HZ
I'm a: Knowledge Seeker
Posts: 61
Default Re: Smd electrolytic capacitor identification

OK. I have updated as you suggested. Attached are 2 photos.

The middle figure is definately the capacitance value in Mf.

If the last figure is the voltage why put F not V?


Any ideas?
Attached Images
File Type: jpg smd1.jpg (484.7 KB, 48 views)
File Type: jpg smd2.jpg (482.4 KB, 38 views)

Last edited by Cornboats; 07-27-2012 at 11:22 AM..
Cornboats is offline   Reply With Quote
Old 07-27-2012, 12:08 PM   #4
mariushm
Badcaps Veteran
 
Join Date: May 2011
City & State: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 3,072
Default Re: Smd electrolytic capacitor identification

That 25f and 16f are not necessarily the voltage rating, but in this case they probably are.

That chip near the capacitors is a 5v linear regulator - it takes in any voltage and outputs 5v.

See http://www.fairchildsemi.com/ds/MC/MC78M05.pdf

So at its input you have 220uF and probably anything higher or equal with 16v, probably 25v. On the output, there's 100uF and since the IC outputs 5v, any capacitor with rating higher than 5v would work there - they probably used 16v rated cap simply because they used the same capacity/voltage rating cap somewhere else and bought the capacitor in volume..

You can grab a multimeter, put it on DC and put the black probe on that tab and the red probe on the two pins and you'll see the voltages while the board runs. First pin is input, last pin is output.

My guess is that they used capacitors rated for 16v or 25v simply to save money by buying in large volume capacitors of the same kind - it would not save much space on the board to go with capacitors rated for less voltage, those would be just a couple of mm smaller in diameter. These surface mounted capacitors generally use the same standard square pad size under certain diameters.

Replace with low esr capacitors rated for at least 16v (25v if you can't measure the voltages now or don't know what voltages the psu delivers) and you should be fine.

Last edited by mariushm; 07-27-2012 at 12:12 PM..
mariushm is offline   Reply With Quote
Old 07-27-2012, 01:39 PM   #5
selldoor
Slow Learner
 
Join Date: Dec 2010
City & State: Lancashire UK
Posts: 6,953
Default Re: Smd electrolytic capacitor identification

If the last figure is the voltage why put F not V?
There is no common configuration for the information on these caps.
Whilst the numeric part of the last figure is probably the voltage ( because it is in the "normal" voltage range for caps) the F probably has nothing to do with voltage as some manufacturers tag on the Series after the voltage.

I suppose we should be grateful for anything its well up on blank ceramic caps.
selldoor is offline   Reply With Quote
Old 07-28-2012, 02:13 AM   #6
Cornboats
Dave
 
Join Date: Oct 2010
City & State: Worcestershire
My Country: United Kingdom
Line Voltage: 240v 50HZ
I'm a: Knowledge Seeker
Posts: 61
Default Re: Smd electrolytic capacitor identification

Many thanks for both of your replies. Its what I suspected but its comforting to know you are both of the same opinion.

Mariushm: Would you know where the 15v supply is derived from on the board? I have a problem with an erratic 15v output on the y-sus which is causing the Zsus ipm to overheat.
Cornboats is offline   Reply With Quote
Old 07-31-2012, 07:10 PM   #7
Duncanbest
Member
 
Join Date: Jul 2012
City & State: Shin-chu
My Country: Taiwan
I'm a: Knowledge Seeker
Posts: 73
Default Re: Smd electrolytic capacitor identification

Maybe these V-cap made by Suncap

http://www.sunelec.co.jp/eng/product/product_02.html

http://www.sunelec.co.jp/eng/catalog/catalog01.html

check marking style
verify CE-FS series

for large capacity
CE-BS series
Duncanbest is offline   Reply With Quote
Old 08-01-2012, 02:01 AM   #8
Cornboats
Dave
 
Join Date: Oct 2010
City & State: Worcestershire
My Country: United Kingdom
Line Voltage: 240v 50HZ
I'm a: Knowledge Seeker
Posts: 61
Default Re: Smd electrolytic capacitor identification

Many thanks for the information. I think your right - There can't be many manufacturers that refer to the Voltage with an "F".

I've printed off technical details and will keep for reference.
Cornboats is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 05:28 PM.


Badcaps.net Technical Forums 2003 - 2014
Powered by vBulletin ®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.

Did you find this forum helpful?