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Old 08-20-2018, 05:10 PM   #1
stevekasian
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Default Unknown Motherboard Recapping

Hi,

I have a friend who gave me his old motherboard to recap.

I am only replacing the visibly bad caps around the CPU, as he allowed the heat sink to become clogged with dust and it overheated the CPU. This went on for some time, damaging the caps nearest the CPU due to the heat. You can see they are clearly leaking and bulging. All other caps look fine (althought I realize they might not necessarily be), and are located much farther away from the CPU than the "gang of 8" I am replacing;-).

My main concern, at this point, is finding suitable replacement parts. The only series I've found on Digy-Key, from any mfgr., which are small enough in diameter are Panasonic FS series caps.

Can anyone tell me if these series are appropriate for a low esr replacement?

Also, if there are any other pitfalls or warnings anyone has for me re. this project, your input would be appreciated.

Thanks!
Steve
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Old 08-21-2018, 12:04 AM   #2
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Default Re: Unknown Motherboard Recapping

Quote:
Originally Posted by stevekasian View Post
You can see they are clearly leaking and bulging.
i dont see any pictures in your post. please post pics of the board so we can identify what board it is. without knowing and being able to see what the cpu vrm design looks like, we cannot tell u what caps to use. sometimes if its a high frequency switching design, u can poly mod the board. if its a low frequency switching design, u can get away with higher esr caps as capacitance matters more for lower switching frequency.

if u dont have a camera, just type on here whatever is written on the stickers and labels on the board so we can roughly guess what kind of a board it is.
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Old 08-21-2018, 01:14 AM   #3
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Default Re: Unknown Motherboard Recapping

Can you tell us what is written on the old (bulged) caps - i.e. name/brand, series (typically a 2-3 letters), Voltage (V), capacitance (uF), and physical size (diameter x height in mm). Most of the time that is enough to determine what capacitors you need.

Also, what CPU socket does the board use? Typically anything with socket 775 or newer (Intel) and AM2 or newer (AMD) will use ultra-low ESR caps. In those cases, now that ultra-low ESR electrolytic caps are out of production, polymer capacitors may be your best option.

Nonetheless, if you can provide some pictures of your board, that would be very helpful too, as we may see other potential issues that you might not be aware of.
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Old 08-21-2018, 03:18 AM   #4
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Default Re: Unknown Motherboard Recapping

Thanks. It says: M/B MBGAY0900103300072EK01, but I don't find anything for that part #.

Please find picts attached. (Please disregard the first one - it's blurry.)

No information on the board is available, and I haven't removed the CPU to find out what kind it is.


Other than the 6.3v 1800uf rating, the caps just have an "FL" after the 105C, and also an "M" inside of a box, which I've recreated in photoshop in a rough manner and attached below with the picts. There is nothing else printed on teh caps.

They are 8mm in diameter and 22mm in height. I found the following on Digi-Key, when filtering only for 6.3v 1800uf radials with 8mm diameters:

https://www.digikey.com/products/en/...=1&pageSize=25
Attached Images
File Type: jpg IMG_20180814_185521.jpg (3.21 MB, 41 views)
File Type: jpg IMG_20180814_185533.jpg (2.89 MB, 35 views)
File Type: jpg Original Capacitor Brand Symbol.jpg (37.8 KB, 13 views)
File Type: jpg IMG_20180814_185508.jpg (3.34 MB, 46 views)

Last edited by stevekasian; 08-21-2018 at 03:31 AM..
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Old 08-21-2018, 03:34 AM   #5
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Default Re: Unknown Motherboard Recapping

Quote:
Originally Posted by stevekasian View Post
Other than the 6.3v 1800uf rating, the caps just have an "FL" after the 105C, and also an "M" inside of a box, which I've recreated in photoshop in a rough manner and attached below with the picts. There is nothing else printed on teh caps.
The "M" inside a box is Matsushita's logo - i.e. Panasonic. FL indicates the series. So you have Panasonic FL caps. These caps are of really high quality - one of the best you can find. So indeed they probably failed due to exposed to high heat for a very long time.

Bad news is you're unlikely to find ultra-low ESR electrolytic caps as good as Panasonic FL.

Good news is, your board certainly looks new enough to use polymer caps. Something like United Chemicon PSC 2.5/4V @ 820-1200 uF should work fine as replacements (at least for the caps around the CPU). There are many other options, of course. Just look up the specs on the Chemicon PSC caps I mentioned above in their datasheet (do a search online for Chemicon PSC and look for PDF files). From memory, I think Nichicon LF and Panasonic OS-CON SEPC (or Sanyo SEPC, if you find New-Old-Stock... ie. NOS parts) are all more or less equivalent to Chemicon PSC and readily available on Digikey and Mouser.

Regarding the motherboard... given the yellow CPU HS retention plastic, I can only think of this board being a Jetway OEM... though they usually use Phoenix bios, so maybe not. Other two candidates are Intel (which is unlikely, as this is an AMD board) and ECS. Probably an ECS.

In any case, the darkening near the CPU area doesn't look very good. What CPU is installed in this motherboard? I'm thinking it may be just right at the TDP limit of what this motherboard can handle, hence the darkening.

Also, this appears to be an AM2/AM2+ board. Many of these boards came either with AMD North/Southbridge shipsets or nVidia GeForce 6150/6200 chipsets. If it's the latter (i.e. a GeForce chipset), put a small 40 mm fan on both the Northbridge and Southbridge heatsinks. If it's an AMD chipset, putting a small fan on the Northbridge is advisable too (but not always required, if case cooling is very good).

And lastly, with this board appearing to come from an Acer PC, it's worth having a look inside the PSU for bad caps as well.

Last edited by momaka; 08-21-2018 at 03:45 AM..
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Old 08-21-2018, 07:02 AM   #6
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Default Re: Unknown Motherboard Recapping

before you buy new caps, check the spacing between the pins on the old ones.
polymers often come with 2 spacing options.
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Old 08-21-2018, 08:05 AM   #7
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Default Re: Unknown Motherboard Recapping

Foxconn board maybe?
Also this has DDR3 RAM so it is an AM3. NVidia MCP for AM3 are fully integrated, there's no external southbridge, so this is an ATi chipset. 780 or 880 northbridge probably.
But yeah those are not really reliable so they would benefit from additional cooling.
I confirm the discoloration around the CPU VRM MOSFET, this doesn't look good. Make sure you don't use a CPU that eats up to much power, and enable Cool'n'Quiet.
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Old 08-21-2018, 05:03 PM   #8
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Default Re: Unknown Motherboard Recapping

Thanks, everyone. Much appreciated help and info.!

Now that I think about it, it does have an 8 core AMD CPU, but not sure which one. I also know that the computer it was in was built as a custom box, so the motherboard and other parts were purchased individually.

Of course, my best option is to replace the mobo, and would be made even more awesome if I could find an exact replacement, as the setup is rather complex and will take forever to get the OS back into proper working shape with a different mobo model.

If anyone has any suggestions as to what this mobo might be, that would really be helpful as well, and would be much appreciated. I didn't notice any discoloration around the CPU; that is a disconcerting detail, and steers me away from repairing rather than replacing.
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Old 08-22-2018, 02:51 AM   #9
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Default Re: Unknown Motherboard Recapping

since this is an acer oem board, finding a replacement board would be very hard, like looking for a needle in a haystack. even if u do find one, sellers typically charge more than an arm and a leg for it. a liver and a kidney is more like it. the board doesnt have any identifying specific model numbers; except for the acer pc model number the board came from, e.g. acer aspire xx-123 or acer veriton xx-123.

your friend shouldnt have let the pc overheat in the first place... i would imagine oem pcs would complain or shutdown if they overheat or get too hot. that would be a "kind" reminder telling u its time to take care of and maintain your pc!

anyway, u need to remove all of the components if u want to recap. this includes removing the ram, cpu *and* including the cmos battery! so try to see what cpu it is. if its too old, probably its time for a new system rather than repairing.
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Old 08-22-2018, 05:38 AM   #10
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Default Re: Unknown Motherboard Recapping

Quote:
Originally Posted by stevekasian View Post
Of course, my best option is to replace the mobo, and would be made even more awesome if I could find an exact replacement, as the setup is rather complex and will take forever to get the OS back into proper working shape with a different mobo model.
If keeping the OS is important to you, then just recap this motherboard rather than buying an exact replacement.

The problem with exact replacement is that it will likely have the same problems in the future (especially if the CPU is right at the top of the TDP that the board can handle).

Meanwhile, a poly-mod recap will guarantee that you're not going to have any cap issue in the near future, especially since polymer capacitors can handle heat a lot better than ultra-low ESR electrolytics (most of which usually have only a 2000-hour endurance rating at max temperature).

Quote:
Originally Posted by stevekasian View Post
I didn't notice any discoloration around the CPU; that is a disconcerting detail, and steers me away from repairing rather than replacing.
It's okay. Not a good thing, but not uncommon either. I have an ECS MCP61PM-AM motherboard (AM2 CPU) that has the same "issue". It came with an Athlon X2 6000+, which is a 95W TDP CPU - the max the mobo can handle. So the VRM on mine has also started to discolor. The good thing about AMD CPUs - at least for socket 939 and AM2 (I'm not sure about AM2+ and AM3) is that they undervolt pretty well. I use CrystalCPUID to under-volt my 6000+ by 0.2V (or more), and that really cuts the TDP down and makes both the VRM and the CPU run much cooler (the CPU temperatures alone drop by 10C). But even if you don't do that, the fact that you have the CPU heatsink cleaned should help quite a bit. Just make sure the rest of the cooling in the system is working well too, and that should keep this mobo working for a few more years (probably enough that the PC becomes obsolete for your use).
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Old 08-22-2018, 10:51 AM   #11
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Default Re: Unknown Motherboard Recapping

This is a 3 phases VRM probably with some random not really efficient MOSFETs. This will not be able to handle a 8 cores CPU properly. I would stick with 65W TDP CPUs, or some lower-end and "newer" 95W. Also this would mean it is an AM3+ board if it supports AMD FX- CPUs.

About the undervoltage, those CPU usually have some room for it. Sadly OEM BIOS don't let you tweak the voltages, but yep getting 0.2V lower isn't unusual. Cool'n'Quiet will take you from 1.35V to 1.1V on 1GHz already.
The Cool'n'Quiet SSDT ACPI table can be tweaked to get lower voltages permanently, although I don't know if you can inject an ACPI table with Windows without flashing the BIOS. With Linux, you can.
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Old 08-22-2018, 05:22 PM   #12
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Default Re: Unknown Motherboard Recapping

Quote:
Originally Posted by ChaosLegionnaire View Post
since this is an acer oem board, finding a replacement board would be very hard, like looking for a needle in a haystack. even if u do find one, sellers typically charge more than an arm and a leg for it. a liver and a kidney is more like it. the board doesnt have any identifying specific model numbers; except for the acer pc model number the board came from, e.g. acer aspire xx-123 or acer veriton xx-123.

your friend shouldnt have let the pc overheat in the first place... i would imagine oem pcs would complain or shutdown if they overheat or get too hot. that would be a "kind" reminder telling u its time to take care of and maintain your pc!

anyway, u need to remove all of the components if u want to recap. this includes removing the ram, cpu *and* including the cmos battery! so try to see what cpu it is. if its too old, probably its time for a new system rather than repairing.
Thanks for the input; However, this is likely not an OEM Acer board, as it was purchased retail from Tiger Direct or some such website.

The PC overheated due to dust collection in the CPU heat sink fins. It did, in fact, regularly shut down on him, but he did not understand why. He didn't get a hold of me and tell me about the issue until it had been shutting down for some time, thus the caps were exposed to extensive heating for a while.
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Old 08-22-2018, 05:37 PM   #13
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Default Re: Unknown Motherboard Recapping

Quote:
Originally Posted by momaka View Post
If keeping the OS is important to you, then just recap this motherboard rather than buying an exact replacement.

The problem with exact replacement is that it will likely have the same problems in the future (especially if the CPU is right at the top of the TDP that the board can handle).

Meanwhile, a poly-mod recap will guarantee that you're not going to have any cap issue in the near future, especially since polymer capacitors can handle heat a lot better than ultra-low ESR electrolytics (most of which usually have only a 2000-hour endurance rating at max temperature).


It's okay. Not a good thing, but not uncommon either. I have an ECS MCP61PM-AM motherboard (AM2 CPU) that has the same "issue". It came with an Athlon X2 6000+, which is a 95W TDP CPU - the max the mobo can handle. So the VRM on mine has also started to discolor. The good thing about AMD CPUs - at least for socket 939 and AM2 (I'm not sure about AM2+ and AM3) is that they undervolt pretty well. I use CrystalCPUID to under-volt my 6000+ by 0.2V (or more), and that really cuts the TDP down and makes both the VRM and the CPU run much cooler (the CPU temperatures alone drop by 10C). But even if you don't do that, the fact that you have the CPU heatsink cleaned should help quite a bit. Just make sure the rest of the cooling in the system is working well too, and that should keep this mobo working for a few more years (probably enough that the PC becomes obsolete for your use).
Some additional info: As it turns out, the "darkening" of the board around the CPU was actually due to dust collection there. So there is no visible heat-related discoloration there, which is a good thing.

Additionally, the CPU & board ran cool when it was properly ventilated (I worked on the machine soon after it was built - in early 2011 or so), so cooling is not an issue so long as everything is operating as it should (i.e. no dust bunnies in there, fans working properly, etc).

So I'll need to go with polymer replacement caps then, I take it. Being as I have done searches on Digi-Key for all radial caps at that rating which are 5mm in diameter, and it only returned the results in the link I provided (here it is again for ease of reference: https://www.digikey.com/products/en/...=1&pageSize=25 ), is there any chance you might be able to point me in the right direction to find suitable polymer replacements?

Thanks!
SK

Last edited by stevekasian; 08-22-2018 at 05:39 PM..
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Old 08-22-2018, 09:41 PM   #14
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Default Re: Unknown Motherboard Recapping

what's the outside diameter & pin spacing?
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Old 08-23-2018, 08:33 AM   #15
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Default Re: Unknown Motherboard Recapping

Quote:
Originally Posted by stevekasian View Post
Thanks for the input; However, this is likely not an OEM Acer board, as it was purchased retail from Tiger Direct or some such website.
If the BIOS looks pretty plain / lacks over-clocking/tuning options, it might just still be an Acer board. Maybe TD or whoever got a bunch of these as overstock from Acer and put their own BIOS onto it (or at least a neutral splash logo so you don't get the whole Acer boot screen).

Quote:
Originally Posted by stevekasian
So I'll need to go with polymer replacement caps then, I take it. Being as I have done searches on Digi-Key for all radial caps at that rating which are 5mm in diameter, and it only returned the results in the link I provided (here it is again for ease of reference: https://www.digikey.com/products/en/...=1&pageSize=25 ), is there any chance you might be able to point me in the right direction to find suitable polymer replacements?
Looking at the pictures your provided, the caps on your board around the CPU are definitely NOT 5 mm in diameter, so check your measurements again. I'm pretty sure they are 8 mm diameter with 3.5 mm lead spacing (LS - i.e. spacing between the two cap leads on the bottom).

With that said, here are some polymer cap options for your considerations:

Nichicon RR5, 1000 uF, 2.5V, 5 mOhms ESR
https://www.mouser.com/ProductDetail...8I1Yxes7vRk%3d

Nichicon RL8, 1200 uF, 2.5V, 7 mOhms ESR
https://www.mouser.com/ProductDetail...YCIQgHLNrpY%3d

Nichicon RE5, 820 uF, 2.5V, 5 mOhms ESR
https://www.mouser.com/ProductDetail...Gs3%2fu0OJI%3d

United Chemicon PSC, 1500 uF, 2.5V, 7 mOhms ESR
https://www.mouser.com/ProductDetail...HE0bWfxA82Y%3d

United Chemicon PSC, 1000 uF, 2.5V, 7 mOhms ESR
https://www.mouser.com/ProductDetail...df2UaVtI120%3d

United Chemicon PSC, 820 uF, 2.5V, 5 mOhms ESR
https://www.mouser.com/ProductDetail...xfBDARt8S6A%3d

Panasonic SEPC (formerly Sanyo SEPC), 1000 uF, 2.5V, 7 mOhms ESR
https://www.mouser.com/ProductDetail...wQA%2fSmYsw%3d

Sorry for including Mouser links and not Digikey links, but currently I'm on an old laptop that can only run Opera 12 (thus making Digikey not accessible for me). But you should be able to find the same cap brands and series above on Digikey.

Also note that the capacitance on all of these suggested caps is less than the 1500 uF caps on your board. But when doing a polymer recap, at least on buck-type regulators (such as the one for the CPU), it is pretty standard to use around half of the capacitance (i.e. 820 uF caps for 1500 and 1800 uF electrolytic caps). This has mostly to do with the fact that polymers offer the same ultra-low ESR as the higher capacitance ultra-low electrolytic caps. And in buck circuits, especially newer ones, ESR is often more important that the capacitance alone. So because of that, most mobo's can be poly-modded without issue.

I personally like to stay both close to the original capacitance and close to the original ESR. So the first two links above is what I would choose if I'm not on a tight budget. Otherwise the cheapest 820 uF @ 2.5V polys will likely work just fine too. Actually, you don't need to limit yourself to Nichicon, United Chemicon, and Panasonic polymers only, as polymer caps in general don't have the same reliability issues as off-brand electrolytic caps. Thus, Wurth Electronic, Kemet, Vishay, and probably many other brands are fine to use too. It's just that Japanese polymer caps have been around for a long time and proven themselves as reliable in the field, hence why I usually recommend them.

Last edited by momaka; 08-23-2018 at 08:40 AM..
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Old 08-23-2018, 10:38 AM   #16
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Default Re: Unknown Motherboard Recapping

Indeed, you can use much lower capacitance than what's already on the motherboard, if you go with polymer capacitors.
They had to go with 1800uF 6.3v or whatever is there, because those capacitors had the volume big enough to allow for very low ESR. Polymer capacitors however have much lower ESR from the start

So you'll be fine with 820uF .. 1500uF 2.5v ..4v rated polymer capacitors, whatever you can find with less than 10mOhm esr (you should easily find with less than 6mOhm)

Here's a starting point: https://www.digikey.com/short/jfnn0b


If you want to stick with electrolytic capacitors, I would say use anything with specs similar or better than Panasonic FM series...

Here's a link to start with : https://www.digikey.com/short/jfnd3b

I put there 1500uf to 2200uF, 6.3v to 10v rating , 5mm lead spacing ... you can use higher voltage rating, you can use more capacitance, slightly less (1500uF) should be fine and I've picked only series of capacitors that are very low esr so you should be fine... just be careful about the height of some capacitors, make sure the cooler you're gonna use will clear the capacitors.
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Old 08-23-2018, 12:56 PM   #17
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Default Re: Unknown Motherboard Recapping

go full Polymer, FM is not even close to being good enough.

Last edited by stj; 08-23-2018 at 01:07 PM..
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Old 08-23-2018, 02:36 PM   #18
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Default Re: Unknown Motherboard Recapping

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go full Polymer, FM is not even close to being good enough.
i don't agree with that statement...

While yes, the FL series of capacitors from Panasonic may be better in specifications compared to FM or FR, it's not really that far off.

That OEM motherboard worked for years with those capacitors slowly degrading and going outside specifications until they eventually died by leaking, popping that electrolyte out of the cases.

So let's say the motherboard functioned with those capacitors going from "0% outside spec" to let's say "15% outside spec" when the board finally died... just for example's sake. So, you could simply say that with FM series capacitors, you would start straight from "2-3% out of spec" and in time, these capacitors may also degrade. Nevertheless, you would still have years of lifetime with those FM series capacitors, and their performance is still within some percentage, some tolerance, they're not that far off from FL series capacitors specs.

Also another thing to keep in mind... this is an OEM motherboard, not one that has BIOS settings really tweaked and optimized for cpu overclocking, memory tuning etc, so the output of the VRM (which is 3 phase crappy one also) is not really that critical if it's super stable or not, that you get very accurate voltage settings or not. You don't have to be super exact.

I'm fairly sure the guys that made the design for this OEM motherboard designed the board for some flexibility, to work with various series of capacitors, not strictly with only the super lowest esr capacitor series.

In this particular example, I suspect those FL series capacitors had accelerated degradation due to being so close to the cpu heatsink. Not having a heatsink on the VRM hurt the capacitors also, since the heat from those mosfets radiated through the motherboard into the leads of the capacitors and warmed them up.

Anyway... nowadays polymer capacitors are not that much more expensive compared to electrolytic capacitors, especially if you buy them in packs of 10 or something like that (at most retailers like Digikey or Newark/Farnell you get discounts if you buy packs of 10 or 25 or higher)
So you could buy polymer capacitors for the VRM as recommended above and you'll get good results with them.
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Old 08-23-2018, 03:41 PM   #19
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Default Re: Unknown Motherboard Recapping

higher ESR = higher internal heating at high frequency's
in short, they commit suicide on high frequency supplies.
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Old 08-23-2018, 05:47 PM   #20
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Default Re: Unknown Motherboard Recapping

Quote:
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Looking at the pictures your provided, the caps on your board around the CPU are definitely NOT 5 mm in diameter, so check your measurements again. I'm pretty sure they are 8 mm diameter with 3.5 mm lead spacing (LS - i.e. spacing between the two cap leads on the bottom).
My bad; I glanced at the search results page I linked to (with a bad link, mind you) and misread what I saw.

They are, indeed, 8mm OD with 3.5mm spacing.

(And DOH! The board says "ACER, Inc." right on it.)

Awesome! Thanks so much for your help, folks.

Now I'm wondering if I bit off more than I can chew with this soldering job. The board has no traces on the back of it connecting to the capacitor leads. And it doesn't look like any are visible on the front. So do I just solder the things in and trust that there are somehow traces imbedded between the laminates?

Last edited by stevekasian; 08-23-2018 at 06:02 PM..
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