k8ngm2/ms-7207 v1.0 - Wrong caps?

[Zero Hour]

I swiped this board from a failed machine at work and kept it around until i start doing more cap replacement. I've had some success but i'm a newbie at it so -
My board had a few (out of 5) bulging KZG next to the cpu. I'm new to this, so i ordered the closest matching caps i could find at the time. They were identical in size and from what i read on the spec sheets of both caps, they were identical (unless i misread or missed a detail like ripple or something). I replaced all 5 caps with nichicon 3300uf 6.3v. I still was not getting any post or activity video-wise (if i recall correctly, the board was powering on which it was not before) so i did the baking 'trick' (yeah baked the motherboard as a last resort) and now the video is working again. My issue is that it will show the emachine screen, and then shows some vague info and cuts off completely each time. Basically a few seconds after emachine screen posting, it cuts off. My question is did I choose the wrong caps? Nichicon 3300uf 6.3v 105c H0906 is all the info i see on the ones i used (can't remember where i ordered them from). Should i have stuck with replacing with equal KZG caps?

[PCBONEZ]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

Unless you tell us which series of Nichicon no one can say.

Nichicon <- Brand
3300uf <- Capacitance
6.3v <- Volts
105c <- Temp
H0906 <- Date Code

That same info probably applies to 20-30 different Nichicon Series' which will all have different ESR and Ripple ratings.
Only 2 or 3 of them are good replacements for KZG.

Next to CPU is usually in the VRM [Vcore side]
ESR is a heck of a lot more important there than uF is.

~
Baking a board with electrolytic caps mounted is probably the worst idea I've heard recently.

~
Don't worry. - You're just new. - LOL
.

[PCBONEZ]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

BTW

(M) <- uF Tolerance [+/- 20%] ..... is not part of the series name.

[Zero Hour]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

I realize baking isn't the conventional method but I've heard of, and performed it on video cards with success. Started doing it on motherboards as a desperate last ditch measure when replacing caps didn't fix the entire problem, and it has worked MIRACLES numerous times. I've done it on two boards in a couple of Acer Veriton L100's, two emachine kcm51g boards (not certain of model number off the top of my head), as well as a few other motherboards. My router machine I did it too when replacing the caps didn't entirely solve the problem, and now i have a nice x2 4200 running win7

OH and sorry for the missed detail

Is "HM(M)" the needed series info?

[Toasty]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

HM matches KZG's spec sheet.

Baking? ROFL
At what temperature? For how long?

You might have more bad caps on there. You may have caused the problem by baking.

Toast

[PCBONEZ]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

Yes HM matches.

Baking is the ghetto version of BGA re-flow.
It will ruin electrolytic caps though and might cause separation of the PCB layers.

[PCBONEZ]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

HM(M)
The HM is the series
The (M) is just the tolerance

[Zero Hour]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

Like i say, desperate last measures

I guess I need to learn how to test the capacitors then.

As far as the baking, it's at 384F for 5 mins typically..

[linuxguru]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

Baking will probably cook the electrolytics, but if the board comes alive it's probably worth it - the electrolytics are usually easier to replace than doing a BGA reflow. The board probably needed a recap anyway.

[Zero Hour]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

Baking will probably cook the electrolytics, but if the board comes alive it's probably worth it - the electrolytics are usually easier to replace than doing a BGA reflow. The board probably needed a recap anyway.

The two acers did need a recap yes, but after the recap i still had no video or lights. After baking, the machines operated with no problems at all to this date (few months so far) One runs 24/7 with Windows 7 as my router/ICS machine.

[samainfirenight]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

I am having this problem as well...the computer will not POST and there is no video display. The fans run, drives come on, LEDs are lit.

I haven't tried the baking trick, and probably won't as this is not my machine, it has been brought to me by a friend for repair. Anyways, on opening the case I noticed that the caps running along side the CPU were blown. So, I took an extra board that I had (it was working) and pulled the 3600uF 6.3v caps off it and replaced the bad ones. This made no difference.

At this point I'm thinking that it is because I pulled them from another board; even though I have done this successfully numerous times. At any rate I took my time and thoroughly examined the board for additional caps, and any other signs of possible damage. None. So I pondered and went to Mouser.com and ordered the five 3600uF 6.3v 105C caps, and the four 1000uF 16v 105C nearby caps for good measure.

Still no difference! The computer is not worse...nor any better! I thought that maybe there might be a problem with the video output so I checked the port (integrated) and there is voltage; 4.93v to be exact, coming through two pins. So I am completely puzzled, and I don't want to toss the board, I know there must be something I can do......

I am at a loss now, any ideas????

[samainfirenight]

Re: k8ngm2/ms-7207 v1.0 - Wrong caps?

Ooops, the additional caps that I ordered for this board were 1500uF 16v 105C. My bad...... I was repairing an IMac G5 at the same time and the 1000uF were for it. The IMac was a success btw, I'm proud of that one! lol