gigabyte 81945m-g-rh

[String2016]

I have a gigabyte 81945m-g-rh which has blown 3 capacitor around cpu line and turns on but no display. I try to change this caps but i don't have the same exact value available. the capacitor have 1500uf 16v and i have only 2200uf 16v is it possible to replace with this 2200uf?please need help

[Per Hansson]

Re: gigabyte 81945m-g-rh

Yes it is, but the important spec is ESR and Ripple current.
You need to look at the datasheets to verify that.

[String2016]

Re: gigabyte 81945m-g-rh

thanks for the response the orginal caps are nichicon and my replacement is jackon caps

[Stefan Payne]

Re: gigabyte 81945m-g-rh

thanks for the response the orginal caps are nichicon and my replacement is jackon caps

What series??

Manfacturer is irrelevant.
Capacitance is not that relevant

What counts is the rest of the spec:
ESR and Ripple Current.

You can't replace an 820uF Nippon Chemicon KZG with a 820uF KMQ just because they have the same uF!!
In this case you have to either use a Panasonic FM 820uF or you can probably go for a Polymer.


So we need more information.
You have to look up the information.

You can't just replace a cap with the same Votlage and Capacitance!

[momaka]

Re: gigabyte 81945m-g-rh

You can't just replace a cap with the same Votlage and Capacitance!

You can .... but you really shouldn't just do that.

Ideally, you indeed should look up the ESR and ripple current specs. But if you have caps that are completely bad (visibly blown/leaking), then replacing them with GP crap caps may still be a bit better than trying to run the equipment with the bad caps. But using GP caps in place of low ESR and/or ultra-low ESR caps (especially on motherboard) may eventually make your new caps fail quickly again. It all really depends where the caps are used, though. If it's not around the CPU, you may have better luck with the caps lasting a bit longer. But don't count on it. Get proper replacement caps the first time if you can and do the repair once, but correctly.

[Wester547]

Re: gigabyte 81945m-g-rh

Are the original capacitors 1500uF 16V Nichicon HM by any chance? This is a 2006 or 2007 vintage board AFAIK, so I would be surprised to hear that the HM failed unless a very shoddy PSU was powering the board in question or unless the VRM runs very hot.

[Dan81]

Re: gigabyte 81945m-g-rh

You can .... but you really shouldn't just do that.

Ideally, you indeed should look up the ESR and ripple current specs. But if you have caps that are completely bad (visibly blown/leaking), then replacing them with GP crap caps may still be a bit better than trying to run the equipment with the bad caps. But using GP caps in place of low ESR and/or ultra-low ESR caps (especially on motherboard) may eventually make your new caps fail quickly again. It all really depends where the caps are used, though. If it's not around the CPU, you may have better luck with the caps lasting a bit longer. But don't count on it. Get proper replacement caps the first time if you can and do the repair once, but correctly.

You can get away with GP caps on the 1000uF 6.3v spots I think.

[momaka]

Re: gigabyte 81945m-g-rh

You can get away with GP caps on the 1000uF 6.3v spots I think.

It depends.

If it's just a regular filter for the 3.3V, 5V, or 12V rail (but not an input to a buck-type regulator), or a filter for a linear regulator, then probably yes.
But if you have a buck-type regulator (one with inductor), GP caps are *not* a good idea.

Of course, anything is better than failed caps. And personally, I would rather take good quality Japanese GP caps over Chinese/Taiwanese low ESR caps. Actually, you could technically use GP caps in a buck regulator without any adverse affects if you also add a lot of MLCCs (high-capacity ceramic caps with 4.7 uF or more) in parallel to the GP caps. ATI used to do this a lot on their Radeon HD2000, HD3000, and HD4000 series of video cards - at least for the high-side of the VRM. For the low-side, it was always polymers and/or low ESR conventional electrolytics.

Are the original capacitors 1500uF 16V Nichicon HM by any chance? This is a 2006 or 2007 vintage board AFAIK, so I would be surprised to hear that the HM failed unless a very shoddy PSU was powering the board in question or unless the VRM runs very hot.

Maybe those were Chemicon KZG? I know Gigabyte usually sticks with Nichicon, so indeed you're correct to assume the caps were Nichicon HM. However, I think I remember seeing a few boards with Chemicon KZG. If not that, perhaps Sanyo WF? I know Gigabyte occasionally used green Sanyo caps, though I never looked to see if they are the WF series or not. WF are indeed dodgy as you've warned me before - I just opened my Gateway GT5656 PC a few weeks ago, and one of them bas bulging just from sitting in storage. Capacity measured over 3x normal. Need I say more?

[Wester547]

Re: gigabyte 81945m-g-rh

Maybe those were Chemicon KZG? I know Gigabyte usually sticks with Nichicon, so indeed you're correct to assume the caps were Nichicon HM. However, I think I remember seeing a few boards with Chemicon KZG. If not that, perhaps Sanyo WF? I know Gigabyte occasionally used green Sanyo caps, though I never looked to see if they are the WF series or not. WF are indeed dodgy as you've warned me before - I just opened my Gateway GT5656 PC a few weeks ago, and one of them bas bulging just from sitting in storage. Capacity measured over 3x normal. Need I say more?

Is it a 1800uF 6.3V Sanyo/Suncon WF? High capacitance = dramatically thinned or damaged anodic oxide layer. Very likely the result of insufficient inhibitors to avert water-driven corrosion (capacitance increases as the oxide layer thins, also reducing the breakdown voltage), although it may also be that when the cap bulged, it damaged the dielectric, causing the high capacitance reading. Sadly I have seen WX and WG fail like that before too (like the bad HM and HN), although not at the frequency that WF does. I only recall ECS and MSI using the WF series, though (and of course, they were present on old Xbox 360 motherboards, and certain Dell motherboards too).

They would be either WG, KZG, HM, MBZ, or FJ on the OP's board (WF is equal to HN, and WG equal to HM) - I wonder if they were KZG too, because I've seen people mislabel KZG as “Nichicon KZG” before.

[momaka]

Re: gigabyte 81945m-g-rh

Yup, 1800 uF / 6.3V Sanyo WF on an ECS MCP61PM-AM rev 1.0A. There were two that were bad, actually, but one wasn't bulging. I just decided to pull a few random ones for a test after I saw the bulged one.

[Stefan Payne]

Re: gigabyte 81945m-g-rh

You can get away with GP caps on the 1000uF 6.3v spots I think.

Yeah, but those are only decoupling caps for +5V for USB.

Those don't really count, do they?

[momaka]

Re: gigabyte 81945m-g-rh

Yeah, but those are only decoupling caps for +5V for USB.

Again, not always.

Looks like you guys need to follow my motherboard recap threads more often (that is, whenever I get to posting one). Here's a board filled with 6.3V/1000 uF caps, and you can see they filter all sorts of stuff:
https://www.badcaps.net/forum/showthread.php?t=63164

FYI, this is not the only motherboard like that. I have seen motherboard from ASUS, Gigabyte, ECS, and Jetway all do this - i.e. use one standard value of capacitors (typically 6.3V/1000 uF or 6.3V/820 uF) for just about every major component rail (the CPU V_core typically being an exception, as always).

[Stefan Payne]

Re: gigabyte 81945m-g-rh

Yeah, because its cheaper to use one component that is overkill for some parts instead of using another place on the machine to use another component.

And you are right, I was too unprecise.

Let me rephrase it:
The decoupling caps, the ones between the PCI slots (if no Voltage regulator is near them) and the decoupling ones for USB can be swapped with GP ones.