Changing voltages.

[Spork Schivago]

Re: Changing voltages.

A bit weird motherboard here. With the caps removed, the mask for the caps have the normal half shaded / half not shaded stuff. But with the old caps, the line that marks what I think is the cathode side goes to the non-shaded side. I've always seen it where the shaded side on the board represents the cathode side. I can use my DMM to check continuity on the pad and see if I can verify the shaded is not the cathode side.

[stj]

Re: Changing voltages.

check it with a meter, some asus boards had the marking the wrong way too.

[Spork Schivago]

Re: Changing voltages.

check it with a meter, some asus boards had the marking the wrong way too.

Yeah, the markings are backwards. This isn't an Asus board but it looks like Asrock had the marking the wrong way too. I figured as much but with those cheap caps, I was thinking maybe the mark wasn't on the cathode side. Glad I checked.

I have all five caps in. Fan speed is still changing, temp goes from 30 degrees C to 35 degrees C and back to 30 degrees.

Vcore is still moving but comes in bursts. Like it appears stable for a bit and then jumps. Same with the other voltages. 12v doesn't seem to move much, if at all.

I'm wondering what other caps I should check...

[Spork Schivago]

Re: Changing voltages.

I'm thinking of just recapping the whole board. Would there be any reason, besides cost, as to why I wouldn't want to use high quality polymer capacitors? What I mean by that is is there any time where they could actually hurt the circuity? Or would they just might be a bit overkill and would work just fine?

[Spork Schivago]

Re: Changing voltages.

I was thinking at least these....what do you think?

Also, with the lower number of phases that this board has, I'm sure that'd affect the output voltage. Maybe that's why those voltages are bouncing a bit?

For the 16v, 1000uF (the tall ones that make up the voltage regulator circuit), do you think United Chemi-Con is a good name? I was thinking maybe these guys: http://www.digikey.com/product-searc...=0&pageSize=25

If they're the ones I'm thinking of, I think they're a real good brand name. Are they the same as Sanyo / Nippon? I saw a post on the Good Capacitor list where someone listed on the same line, Sanyo / Chemi-Con / Nippon. So I was thinking maybe they were the same and the company just changed names?

[stj]

Re: Changing voltages.

the 4 at the top are the important ones, they supply the vrm regulator.

maybe the monitoring chip has issues - try looking with the scope.

[ChaosLegionnaire]

Re: Changing voltages.

hmm for some reason digikey lists the ncc/ucc psg caps as general purpose?! typically, they use psc caps for vrm use. however, looking at the esr and ripple of the psg series, it should do fine for vrm use as well. not to mention its super ultra long life of 20k hours! nice! however, i wonder if the capacitance u chose is too high cuz u are now poly modding the vrm input? they say to half the capacitance or sumthing if u are polymodding?

I'm thinking of just recapping the whole board. Would there be any reason, besides cost, as to why I wouldn't want to use high quality polymer capacitors? What I mean by that is is there any time where they could actually hurt the circuity? Or would they just might be a bit overkill and would work just fine?

certain areas of the board dont really need ultra low esr poly caps. besides the cpu vrm in and out that need polys, the caps around the dimm slots could use polys as there have been a number of boards around the site with bad caps around the dimm. the caps around the video card x16 slot could also be polymodded to protect against cap failure if a hot and powerful high end video card was used.

[Spork Schivago]

Re: Changing voltages.

the 4 at the top are the important ones, they supply the vrm regulator.

maybe the monitoring chip has issues - try looking with the scope.

Yeah, I learned those 4 at the top are also part of the VRM regulator. I just didn't have any replacements on hand so I had to order them.

I think the one next to the CPU fan connector might be for the actual fan, so I'll replace that as well. Then there's one by the RAM and one by the 24-pin ATX power connector. Is the one by the RAM for the RAM? The one by the 24-pin ATX connector, what's that for?

[Spork Schivago]

Re: Changing voltages.

hmm for some reason digikey lists the ncc/ucc psg caps as general purpose?! typically, they use psc caps for vrm use. however, looking at the esr and ripple of the psg series, it should do fine for vrm use as well. not to mention its super ultra long life of 20k hours! nice! however, i wonder if the capacitance u chose is too high cuz u are now poly modding the vrm input? they say to half the capacitance or sumthing if u are polymodding?

See, I saw different stuff on that. I had asked earlier here because I wasn't sure. Someone on another form said the polymers fire like 100 faster or something and you should either half the capacitance or one third it. With the new polymers in there (just the five polymer looking ones by the CPU socket), it POSTs and doesn't seem to cause any issues...according to this website: http://www.capacitorguide.com/polymer-capacitor/

I can just do a direct replacement most of the time. I just wonder how accurate that information is. There seems to be differing opinions on different sites...

According to this site though, http://www.capacitorlab.com/capacitor-types-polymer/

I need to half the capacitance if the polymer has low ESR.

certain areas of the board dont really need ultra low esr poly caps. besides the cpu vrm in and out that need polys, the caps around the dimm slots could use polys as there have been a number of boards around the site with bad caps around the dimm. the caps around the video card x16 slot could also be polymodded to protect against cap failure if a hot and powerful high end video card was used.

I debated doing the whole board. I ordered a bunch of polymer caps. I'm replacing all of the 1,000uF, 16v ones. The smaller ones I'm just going to leave. He doesn't use any add-on cards at all. Even a mid-range add-on video card would be an improvement I think but he just uses the PC for e-mail and on-line banking.

I'm also replacing the ones by the RAM and ATX power supply. I figured most of those 1,000uF, 16v caps probably wouldn't really benefit from the ultra-low ESR / high ripple. I think polymers generally last a long time though compared to some electrolytics so I just went with it. It wasn't really expensive.

Those 20,000 hour ones blew my mind away! I thought maybe it was a typo and they really meant 2,000 hours! That's insane, isn't it?? Too bad I couldn't find proper values that had that life expectancy for all the caps!

[Spork Schivago]

Re: Changing voltages.

The red boxes are the ones I'm replacing with polymers. The blue box are the ones I replaced with polymers. I know a lot of the red ones are probably going to be overkill.

I placed the order late last night. I really hope I didn't mess up and really need to half or a third the capacitance. I really hope using these polymers don't mess things up.

Also, if I'm not mistaken, there are two real polymers already on here. The one by the top right of the DIMM slots (next to the four pin CPU fan connector) and the one between the IDE connector and SATA connectors. I think they're high quality as well. I believe they're Nichicon's.



They say on them:
lf
560
j 5k
891


The j is the voltage code and means 6.3v. The 560 is the capacitance and the lf I think was the series. The 891 was a date / manufacturer code I believe.

[ChaosLegionnaire]

Re: Changing voltages.

I think the one next to the CPU fan connector might be for the actual fan, so I'll replace that as well.

nope. budget boards rarely have any caps for the fan headers. they're also not really useful unless u have multiple fans connected to the same fan header via a y-cable. also the voltage on the cap doesnt say its 16v. so its definitely not for the fan. most probably a buck regulator for the ram.

Is the one by the RAM for the RAM?

most probably. the caps have to be as close to the load as possible for the fastest possible response to transient loads, i believe. thats why u see cpu vrm output caps so close to the cpu. tho its a double edged sword and also kills the caps faster if the cpu heatsink isnt adequately ventilated.

The one by the 24-pin ATX connector, what's that for?

it could be a buck regulator for the standby rail or the other main rails. just probe the shaded side (which appears to be the positive terminal on asrock boards too) with a multimeter to find out what voltage it is for.

Those 20,000 hour ones blew my mind away! I thought maybe it was a typo and they really meant 2,000 hours! That's insane, isn't it?? Too bad I couldn't find proper values that had that life expectancy for all the caps!

yea thats a nice find. didnt know they made such long lasting poly caps. i thought ultra low esr 5k hr poly caps were all that they made cuz thats what they were made for! mobo use. tho i do know that chemicon also makes 10k hour wet electrolytic caps for low-esr psu use which behemot sells.

and i also downloaded the psg datasheet. its not a typo. the datasheet really says 15k-20k hours!

I know a lot of the red ones are probably going to be overkill.

well that depends if its a free or paid repair. if its a paid repair, your friend is going to complain about the ex$$$ bill for polymodding that u are going to send to him! if its free, u broke your wallet unnecessarily on a pc that is only going to be used for light work. btw, i would also slap a fan on the northbridge. those gmchs can get pretty hot!

I really hope I didn't mess up and really need to half or a third the capacitance. I really hope using these polymers don't mess things up.

it depends what the original esr value was and how much higher/lower it was. there are poly caps out there with similar esr spec to electrolytics (ruby mbz/nichicon hm/panasonic fj/sanyo wg). those can be used without having to change the capacitance. if the esr is much lower than the original caps, u may have to half the capacitance.

anyway, the asrock g31 board is considered a recent modern board. it shouldnt complain about being polymodded unlike the p4 boards.

[Wester547]

Re: Changing voltages.

Just to clarify something a bit earlier.... those 680uF / 4V capacitors in the VRM output are not polymers. They are regular electrolytics, presumably by Suncon / Sanyo going by the font. They have the same K vent stamp as other Suncon capacitors do. They don't always bear a vent stamp because 8x8 680uF 4V liquid electrolytic capacitors don't contain enough "juice" to catastrophically explode when they fail, so they don't need the pressure relief vent necessarily (680uF 4V TMVs and TMJs by NCC don't have vent stamps either, although they do have their date and factory codes marked into the top of the can). The worst they will do is bulge, likely from the bottom but possibly the can as a whole.

They read high capacitance because their leakage current is high, which alludes to a faulty dielectric. Either the electrolyte has broken down and can no longer supply the dielectric with enough oxygen to correct defects in the oxide film and heal itself or the electrolyte doesn't contain enough oxidizers and corrosion inhibitors to control the aggressive water-base electrolyte so it's consuming the anodic dielectric more or less. And one of those capacitors looks like it's leaking.

The 15,000 hour - 20,000 hour polymers aren't a typo. Some wet electrolytics are rated for that as well, although they aren't really low ESR in comparison (they're designed for LEDs and electronic ballasts, IE very hot environments which mandate long life).

[Spork Schivago]

Re: Changing voltages.

nope. budget boards rarely have any caps for the fan headers. they're also not really useful unless u have multiple fans connected to the same fan header via a y-cable. also the voltage on the cap doesnt say its 16v. so its definitely not for the fan. most probably a buck regulator for the ram.

most probably. the caps have to be as close to the load as possible for the fastest possible response to transient loads, i believe. thats why u see cpu vrm output caps so close to the cpu. tho its a double edged sword and also kills the caps faster if the cpu heatsink isnt adequately ventilated.

it could be a buck regulator for the standby rail or the other main rails. just probe the shaded side (which appears to be the positive terminal on asrock boards too) with a multimeter to find out what voltage it is for.

yea thats a nice find. didnt know they made such long lasting poly caps. i thought ultra low esr 5k hr poly caps were all that they made cuz thats what they were made for! mobo use. tho i do know that chemicon also makes 10k hour wet electrolytic caps for low-esr psu use which behemot sells.

and i also downloaded the psg datasheet. its not a typo. the datasheet really says 15k-20k hours!

well that depends if its a free or paid repair. if its a paid repair, your friend is going to complain about the ex$$$ bill for polymodding that u are going to send to him! if its free, u broke your wallet unnecessarily on a pc that is only going to be used for light work. btw, i would also slap a fan on the northbridge. those gmchs can get pretty hot!

it depends what the original esr value was and how much higher/lower it was. there are poly caps out there with similar esr spec to electrolytics (ruby mbz/nichicon hm/panasonic fj/sanyo wg). those can be used without having to change the capacitance. if the esr is much lower than the original caps, u may have to half the capacitance.

What would be considered much lower? If the old ones have an ESR of something like 0.38 ohms but the new ones have an ESR of 0.02 ohm, would that be considered much lower?

anyway, the asrock g31 board is considered a recent modern board. it shouldnt complain about being polymodded unlike the p4 boards.

Thanks for the info. He's a good friend, he paid 100$, even though I told him not too. So far, I've spent around 100$ for the caps and PSU. I doubled the order for caps though. I normally do that, to build a little collection, you know? So in reality, for the caps, I really only spent about 20$ on them. The order came to 50$, but I had a 12$ tip in there as well for me. And doubled all the caps....38 / 2 = 19$. That's not too expensive I wouldn't think.

For the buck regulators, all a buck regulator is something that steps down the voltage while stepping up current, right?

Thanks!

[Spork Schivago]

Re: Changing voltages.

Just to clarify something a bit earlier.... those 680uF / 4V capacitors in the VRM output are not polymers. They are regular electrolytics, presumably by Suncon / Sanyo going by the font. They have the same K vent stamp as other Suncon capacitors do. They don't always bear a vent stamp because 8x8 680uF 4V liquid electrolytic capacitors don't contain enough "juice" to catastrophically explode when they fail, so they don't need the pressure relief vent necessarily (680uF 4V TMVs and TMJs by NCC don't have vent stamps either, although they do have their date and factory codes marked into the top of the can). The worst they will do is bulge, likely from the bottom but possibly the can as a whole.

They read high capacitance because their leakage current is high, which alludes to a faulty dielectric. Either the electrolyte has broken down and can no longer supply the dielectric with enough oxygen to correct defects in the oxide film and heal itself or the electrolyte doesn't contain enough oxidizers and corrosion inhibitors to control the aggressive water-base electrolyte so it's consuming the anodic dielectric more or less. And one of those capacitors looks like it's leaking.

The 15,000 hour - 20,000 hour polymers aren't a typo. Some wet electrolytics are rated for that as well, although they aren't really low ESR in comparison (they're designed for LEDs and electronic ballasts, IE very hot environments which mandate long life).

Thank you Wester547. I figured out they were electrolytics. I've learned a bit about polymers since I started working on this motherboard. The leaky stuff on the board gives it away I believe. Polymers shouldn't have liquid inside if I understand everything correctly.

What gets me is why my ESR meter doesn't detect them as leaky. The ESR value for all of them is extremely low as well, like 0.02 ohm I want to say. I would have thought he ESR value would be higher.

I know you said you thought, by judging by the font, that they were maybe Suncon / Sanyo. I was thinking they were those JFD ( http://www.aliexpress.com/item/Alumi...208.4.8.XWGlVO )

They look identical, even that weird little j. The only difference is the 79 on the top there.

Thanks!

[Spork Schivago]

Re: Changing voltages.

The ones in the VRM circuit got replaced. Voltages still changing, RPM still changing. I started recapping the rest of the board. Because I didn't half the capacitance, once I get the RAM ones done, the one by the fan connector and the one by the chip with the heatsink (nb maybe?) I tested it. It posted and the fan and voltages were stable! It was a pain replacing them by myself. I waited till my wife got home and it took around 30 minutes or so, with her help, to recap the rest of the board. One of them turned out to be 470uF, 16v, not 1,000uF 6.3v. Wasn't exactly sure where it came from though because I stupidly assumed they were all the same. I had a good idea because only four of them I couldn't read. I decided it's the top one by the PCI-E slot. I contacted the company to make sure.

Out of the rest of the board, 9 of them were leaky!!! Once the 470uF 16v one comes, I'll put that in and hopefully it still posts!

[Spork Schivago]

Re: Changing voltages.

Just got off the phone with Uncle Al. He's mad at me for having his system so long. He asked why I replaced the caps. I told him they were bad. He said he just wanted the system clean. The programs weren't opening, the system would take 10 minutes (sometimes 15) to shut down (he timed it) and it would crash. He says it only crashed once, the shutdown thing didn't bother him because he'd just go to bed and the programs weren't loading because they weren't transferred off the hard drive properly (I don't know he means by that). Chrome wouldn't load. Firefox did after a couple reboots. I tried telling him with that many leaking and one bulging, it was just a matter of time before it wouldn't start at all. Now I'm frustrated!

[stj]

Re: Changing voltages.

that's why i dont fix pc's for other people - they dont have a clue and think all problems are software.

[Spork Schivago]

Re: Changing voltages.

that's why i dont fix pc's for other people - they dont have a clue and think all problems are software.

Yeah. He was calling just about every night talking about how his programs wouldn't load but he's convinced they just weren't properly transferred from the hard drive. I asked what he meant by that and he said something about the old hard drive. He used to have those programs on the old hard drive and because the old hard drive was hooked up to his computer, something about parts of them were on the old drive, parts were on the new drive and he just thinks it wasn't be loaded properly or something. He said if I could just copy the rest of the firefox and chrome over, it'd be fine. I tried telling him we downloaded them from the internet and installed them but I don't think he understands.

[Spork Schivago]

Re: Changing voltages.

I was thinking of waiting until tomorrow and calling him and telling him I could put the old caps back in if he wanted. It wouldn't take long at all with Jessica's help.

[diif]

Re: Changing voltages.

Always keep the customer updated on what you find and the progress of their repairs. PCs have become important in day to day life and can't be gone to long without a valid reason.

I always clone a customers hard drive before I do any work. That way if anything goes wrong or something is missed getting copied over it can always be retrieved.

Did you not copy over the Firefox and Chrome profiles from the old PC ? If they are copied over the customer wouldn't even know it had been reinstalled. Even the last session is kept.

Have you run checks on the memory and hard drive ?