Polymer Capacitors for Asrock Motherboard - URGENT advice!

AnonzaRVZ

New Member
Joined
Nov 21, 2019
Messages
6
Hi Internet Peeps.

I am in desperate need for guidance on what capacitor I should buy to fix my Asrock Z68 Fatality motherboard.

So I accidentally nudged a Gold cap on my Motherboard, it burst and now having major issues.

In essence, I need to find a replacement Capacitor for a cap that is labeled as: LF 820 e 17A

Does anyone know what cap I can use to replace this? For the life of me, the original Caps are impossible to source.
I have looked everywhere but can not get it!

They appear to be Japanese made caps, So I doubt I will be able to get the same ones.

However, I need to revive my Motherboard.

Any Advice?

P.S - See the image attached, as this shows the Cap in question (PCE16)

Thanks in advance!!

Regards,
Richard
 

Attachments

  • PCE16.png
    PCE16.png
    366.3 KB · Views: 52
Last edited:

Arcsine

Active Member
Joined
Oct 25, 2009
Messages
35
Judging by the datasheet for that cap (https://www.nichicon.co.jp/english/..._Aluminum_Solid_Electrolytic_Capacitors_E.pdf) it is a Low ESR 820uF 2.5V cap. There are 3 important bits there. The first is the 'Low ESR' this is important since the cap is being used for a high frequency switching supply. The cap needs to have a low ESR to prevent it from heating up too much during operation. This cap has an ESR of 0.007 ohm, so you need one that has the same value or lower. The second part is the 820uf. This is the value for the cap. generally you want the same size or the next largest size you can find, which will most likely be 1000uF. There is on caveat though in that larger value caps are physically bigger. The third part is the voltage rating. This is the maximum DC voltage the cap can handle, again you can use the same value or the next largest. The solid polymer is not that important and will only affect the lifespan of the cap. Judging by the picture it is a through hole part.

You can look at any of the following sites:

PS:
Don't use your motherboard in the mean time since you risk damaging some components. That cap is used to smooth the voltage output of a small power circuit. Without it the voltage may spike to dangerous levels.

Edit:
Fixed info above, thanks @ponder and @Jake45
 
Last edited:

Jake45

Expert Member
Joined
Dec 21, 2014
Messages
2,491
Is that a Nichicon capacitor? It could be from the PLF series of conductive polymer aluminium solid electrolytic capacitors. I think it is an 820uF 2.5V. The 17A is probably a lot number.

Take a look at page 62 ...

One of these might be a suitable replacement from RS Components in Midrand. You need to check the diameter. Is it 6.3mm, 8mm, 10mm or something different?

You could ask Mantech to order one for you. They do sell some Nichicon types. You need to know the diameter and length.

Otherwise you will need to try Mouser, Digikey or Aliexpress etc. Check the diameter and length.
 

Arcsine

Active Member
Joined
Oct 25, 2009
Messages
35
Lol, snap. Just a note though, on the data sheet 820 is 82uF (calculated as 82 x 10 ^ 0). The above is correct.
 
Last edited:

Jake45

Expert Member
Joined
Dec 21, 2014
Messages
2,491
e is 2.5V E is 25V AND it should be 82uF and not 820uF which means that all of the parts that I posted above are incorrect!
 
Last edited:

upup

Executive Member
Joined
Jun 1, 2009
Messages
8,430
You can also try an computer shop, looking for similar component on a old motherboard.
 

Jake45

Expert Member
Joined
Dec 21, 2014
Messages
2,491
Maybe the best option would be to try to ask Nichicon for a sample as it seems that it is much more difficult to find a suitable 82uF rather than an 820uF replacement. In most cases the exact size and type of capacitance might not matter too much but there might be a few cases where it could. Try the sample request or contact us buttons to see if you have any luck.

Those type of low voltage capacitors are usually used in the regulator circuits and might be required to handle high currents. Each phase of the regulator circuit is supposed to be identical so I would personally prefer to replace it with the same part if possible if it's being used for this purpose.

Otherwise you could try the 100uF or the 82uF parts from RS Components mentioned by arcsine if you think they will fit!
 

ponder

Honorary Master
Joined
Jan 22, 2005
Messages
91,062
Lol, snap. Just a note though, on the data sheet 820 is 82uF (calculated as 82 x 10 ^ 0).

e is 2.5V E is 25V AND it should be 82uF and not 820uF which means that all of the parts that I posted above are incorrect!

What's printed on the can is the capacitance.

LF 820 e 17A

Thus part number= PLF0E821----

10^1=10
82*10=820uF

Nichicon doesn't make a 2.5V 82uF cap in this series, if they did the can would have 'LF 82 e' printed on it and the part number would be PLF0E820---- (10^0=1 and 82*1=82)

745391

745393

@AnonzaRVZ You'll have to measure the diameter & length of the case to determine the exact part number as there are three different sizes, 6.3x9, 8x9, 8x12mm with different electrical characteristics.
You should be able to order from mouser/digikey etc or find an alternative.
 
Last edited:

Arcsine

Active Member
Joined
Oct 25, 2009
Messages
35
What's printed on the can is the capacitance.
Ah I see, you are indeed correct, thanks. What a confusing datasheet though using different numbering schemes for part number and physical value.

e is 2.5V E is 25V AND it should be 82uF and not 820uF which means that all of the parts that I posted above are incorrect!
I'm sorry, you were correct with 820uF in your first post.

Looking further I guess this makes sense. Judging by the picture this is somewhere around the CPU and most of the voltages required around there are < 2.5V. At such a low voltage it will have to be quite high value to be so big.
 

Jake45

Expert Member
Joined
Dec 21, 2014
Messages
2,491

AnonzaRVZ

New Member
Joined
Nov 21, 2019
Messages
6
@Jake45 @Arcsine @MightyQuin @ponder @Steamy Tom

Thank you for such great help!

It is such a shame that I can not find the original Cap anywhere.. I have literally Googled for a few days with no luck.
I guess my best option is to take the advice from you all and measure the diameter of the cap currently on the Mobo and then try get the closest I can to that cap. One last question though. With regards to the ESR, having a lower ESR is better is it not? The lower the ESR the less heat the cap generates, correct?

I have therefore this list: https://www.mouser.co.za/Passive-Co...s/_/N-bjufe?P=1z0wrjoZ1ypvpvnZ1yj7skrZ1yzxn8l

I can choose either 7mOhm or 5mOhm.

What would be best?

Thanks again, legends!
 

ponder

Honorary Master
Joined
Jan 22, 2005
Messages
91,062
I guess my best option is to take the advice from you all and measure the diameter of the cap currently on the Mobo and then try get the closest I can to that cap.

Post the diameter & length here so we can determine the correct part# and take it from there.

The originals are definitely available from mouser & digikey.

Where you located?
 

AnonzaRVZ

New Member
Joined
Nov 21, 2019
Messages
6
@ponder

I shall do so when I get home to see the board.

When you say the length, do you mean from the top of the cap to the bottom of the cap or from the top of the cap to the bottom of the pins?

Just want to be accurate.
 

AnonzaRVZ

New Member
Joined
Nov 21, 2019
Messages
6
Hi @ponder

I have measured the cap.

Its 6mm width and 8mm heighdth.

What cap do you suggest for my needs?

Keep in mind that the operating temps will be no more than 80c at the worst case scenario.

Thanks a mill for the guidance and assistance thus far!

Kind regards,
Richard
 

ponder

Honorary Master
Joined
Jan 22, 2005
Messages
91,062
Hi @ponder

I have measured the cap.

Its 6mm width and 8mm heighdth.

Sounds like the 6.3x9mm PLF0E821MCO8

Will get back to you.

EDIT: Gonna paste some stuff below for now which I will compare with the nichicon datasheet later to be sure,
2SEPC820MW
The panasonic 2SEPC820MW seems to be a near exact match except for the tangent of loss angle (tan δ)
 
Last edited:

AnonzaRVZ

New Member
Joined
Nov 21, 2019
Messages
6
@ponder

Thanks so much.

I really do appreciate the time and effort put into this!

You are a legend!

I will reach out to Mantech o RS-Online to get the cap.

Cant wait to solder this and test.

I will keep you updated!

Regards,
Richard
 
Top