ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

[c_hegge]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

^
Depending on which revision your board is, go with one of the following:

https://www.badcaps.net/store/produc...roducts_id=161 for rev 1.0b
or
https://www.badcaps.net/store/produc...roducts_id=180 for rev 2.2

Those kits have all the required caps in the correct diameter.

[lucidbarrier]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

I have one of these MCP61PM-HM that I've had for years now. It has TK 6.3v 1800uf on the VRM. I am wanting to do what you do did and go all polymer on the VRM, 2.5V 820uf.

The other 6.3v 1800uf, I am having trouble finding a replacement in the 8mm can size. All the other caps are all 10mm, except for a general purpose Nichicon cap. I have looked on both Digikey and Mouser. Couldn't I just buy replace them with polymers? They seem pretty cheap if you buy them in 10 or more. I don't understand how to pick the polys, it seems that people buy polys that are both less in voltage rating and capacitance.

[c_hegge]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

Does the smallness of the brown spot and the slightness of the bulge mean the capacitor is still mostly functioning?

No. That cap is dead.

C_hegge's comment that other capacitors are being forced to take up the slack suggests a third option should be considered: soldering an additional capacitor to the underside of the motherboard without removing the one that's failing. (Because my motherboard is running on my desk instead of being installed in the computer case, I'm not constrained by the narrow gap between motherboard & case; there's room to add components to the underside.) The new capacitor wouldn't have a mechanically strong connection because it would be held on only by solder and electrician's tape, but I would promise to be careful to avoid stressing it mechanically.

It may work, or it may not. If the cap fails open, (ie, acts as if it weren't installed), then it may work. Caps can also fail shorted or with high leakage current (ie, act as if a jumper wire were installed across the pins). This will kill the transistors and installing an extra cap is not going to make a bit of difference.

What is worrying me more is that the board appears to have bad Sanyo WGs, which is highly unusual as they are a very reliable cap. Make sure you don't also have bad caps in your PSU.

[SolderTrouble]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

I've attached two close-up photos that show the capacitor that has the small brown (electrolyte) spot and very slight upward bulge at its vent. The bulge is hard to see clearly because it's so slight... the photo shot from the side is the better view. The photo shot from above is the better view of the brown spot. I believe the zillion tiny white particles are dust motes, not leaked electrolyte.

The photos were shot about 6 months ago. To my eye, the capacitor still looks the same now... the bulge & spot haven't gotten any larger.

Does the smallness of the brown spot and the slightness of the bulge mean the capacitor is still mostly functioning? In other words, do the smallness and slightness decrease the probability that this capacitor will cause other capacitors to fail, compared to what the probability would be if the spot & bulge were larger?

If so, it may shift the balance between the risk of replacing the capacitor versus the risk of not replacing the capacitor.

C_hegge's comment that other capacitors are being forced to take up the slack suggests a third option should be considered: soldering an additional capacitor to the underside of the motherboard without removing the one that's failing. (Because my motherboard is running on my desk instead of being installed in the computer case, I'm not constrained by the narrow gap between motherboard & case; there's room to add components to the underside.) The new capacitor wouldn't have a mechanically strong connection because it would be held on only by solder and electrician's tape, but I would promise to be careful to avoid stressing it mechanically.

(By the way, the motherboard photo attached to my previous message was a stock image copied from HP's website.)

Thanks again!

[c_hegge]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

It's on the CPU VRM low side. For now, the other caps will be taking up the slack, but it will put more stress on them.

[SolderTrouble]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

@c_hegge: I appreciate the advice. I'd appreciate more detail about the risks and tradeoffs if possible, because there's also a risk of destroying the motherboard if/when I try to unsolder the failing capacitor.

In case it helps to evaluate the risks, the capacitor that's failing is the one circled in red in the attached photo of the motherboard.

[c_hegge]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

^
Fix it now before it damages something else.

[SolderTrouble]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

@Lucidbarrier: Thanks for commenting.

Perhaps I should have tried setting my soldering station to a temperature higher than 450C. But I was reluctant to risk destroying some component with too much heat.

I only replaced 3 of the old capacitors--the ones that had obviously leaked electrolyte or bulged upward--because replacing them was so difficult and because the computer worked properly after replacing those 3.

I didn't reinstall the motherboard or peripherals back into the system case, because I figured there's a significant probability that I'll need to replace another capacitor, and it was a lot of labor to remove motherboard from case for desoldering/soldering, and I can easily keep an eye on the remaining old capacitors with the computer running sprawled on my desk without its case. One more capacitor developed a slight bulge and a small brown electrolyte spot on top about 8 months ago, but it hasn't seemed to impair the operation of the computer.

[lucidbarrier]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

To heat both holes simultaneously, is a wide chisel tip best? Does anyone manufacture a soldering iron tip that ends in two points, with the distance between the points the same as the distance between the holes?

Removing capacitors in monitors and tvs are pretty cake after some practice. I've always had trouble removing caps in a lead free motherboard and xbox 360. I have been using a 40W radio shack iron. I practiced removing caps on spare motherboards with varying success, even with the stainless steel dental picks.

Recently, an OST cap failed on my A740GM-M near one of DIMM slots and the thing wouldn't boot with RAM installed in both slots. I decided I wanted to try the chisel tip out and bought a cheapie Weller SP40N 40W iron with that comes with a large chisel tip. The iron got hot really fast, and surprisingly melted the lead free solder very quickly. I pressed the chisel tip against both pads and pulled the cap right out frustration free. Then I used the dental pick on the opposite side and pressed the chisel tip again on the pad and the pick went straight through the hole. It was amazing.

I really want to get a regulated iron with adjustable temperature settings. The quality of the iron and the type of tip you use is really important.

[SolderTrouble]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

Since the technique of heating the old solder while pushing in the new capacitor is likely to be generally useful--an alternative to removing the old solder--I wrote about it in a more general thread titled "How to remove leftover solder":

https://www.badcaps.net/forum/showth...n+solder+holes

That thread is in the "Equipment Usage, Soldering, Techniques and Reviews" subsection of the "Electronics Theory and Troubleshooting" section. (It's not a recent thread, so I'm wondering whether I should have started a new thread.)

[SolderTrouble]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

The technique of pushing the capacitor in while heating the solder-clogged hole from the bottom side (as described above) worked, but I discovered it helps a lot to first trim the length of the capacitor lead so the lead won't bend during the pushing. (When I first tried doing it while the lead was long, it went only partway into the hole before a bend appeared, and got stuck there. I had to heat the hole again while pulling the cap to get it out... after which I trimmed the lead and succeeded.)

I suppose one would need to trim both leads if both holes are clogged so you need to heat both holes simultaneously. A question: Should the leads be trimmed to slightly different lengths? I'm thinking this would make it easier to make sure both leads are properly aligned with the holes before pushing them in... less chance of a lead slipping off center during the pushing. Only one lead at a time would need to be carefully held properly aligned: First the longer lead would be pushed a little into its hole while heating only that one hole. Then only the shorter lead would need to be carefully held aligned, when both holes are heated.

I'm wondering if one of these two techniques--either c_hegge's technique of heating both clogged holes simultaneously while pushing in the new capacitor, or "my" technique of cleaning the old solder from only one hole and pushing in the new cap while heating only the clogged hole--may in general be easier and/or safer than the normal procedure of cleaning out the old solder from both holes. Does anyone think it would make sense to skip the normal step of trying to clear the old solder from both holes, and instead either clear the old solder from one hole, or from neither hole?

To heat both holes simultaneously, is a wide chisel tip best? Does anyone manufacture a soldering iron tip that ends in two points, with the distance between the points the same as the distance between the holes?

[SolderTrouble]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

c_hegge wrote: "If the solder refuses to come out, then I don't clean it. I just put a bit of fresh solder over the holes, and hold the soldering iron over both holes to keep the solder melted as I push the new cap in."

Thanks. In my case, only one of the two holes is clogged, so it's unnecessary to heat both holes at the same time... one of the two leads of the new capacitor can slide freely into the unclogged hole while the new capacitor is pushed and the blocked hole is heated. I think I've already tried this, though. But since I don't remember for certain whether I'd added enough fresh solder to the clogged hole before heating it, I'll give it another try and report the result.

[c_hegge]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

If the solder refuses to come out, then I don't clean it. I just put a bit of fresh solder over the holes, and hold the soldering iron over both holes to keep the solder melted as I push the new cap in.

[SolderTrouble]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

Hi, I've noticed that several posters here had trouble removing the old solder from the motherboard holes. Me too! The old solder doesn't seem to want to melt.

I've been trying to recap my motherboard (using the caps kit I purchased a few weeks ago from Badcaps). The project is turning out to be much harder than when I practiced on a trashy old board. Every step--removal of old cap, clearing hole of old solder, and getting new solder joint to adhere to hole's solder pad--has been much tougher than expected.

The motherboard is an ECS MCP61PM-HM Rev 2.1 used in an HP Pavilion m8400f pc:
http://h10025.www1.hp.com/ewfrf/wc/d...c01357175#N467

At the moment, I'm unable to clear old solder from one of the holes.

I don't think my iron is the problem. It's a 60W temperature-controlled station set at 450C (confirmed by the temperature probe of my multimeter) and I've tried 3 different tips for the iron: chisel, point, and narrow chisel.

I've tried a bunch of techniques:

Melting some new solder onto the bottom of the solder pad (to improve thermal contact between old solder and iron's tip).
Iron's tip on solder pad (bottomside) with vacuum bulb on topside.
Iron's tip on solder pad (bottomside) with vacuum bulb on bottom.
Iron's tip on dental pick tip & solder pad (bottomside).
Pushing dental pick on topside while iron's tip on solder pad (bottomside).
Pushing dental pick on topside while iron's tip on dental pick tip.
Pushing a capacitor lead on topside while iron's tip on solder pad (bottomside).
Pushing a capicitor lead on topside while iron's tip on cap lead.
Iron's tip on solder pad (bottomside) with spring-actuated solder vac on topside.
Iron's tip on solder pad (bottomside) with spring-actuated solder vac on bottom.

The problems I've experienced with the other steps may be related. When desoldering an old cap, it takes a long time (about a minute) applying heat before the old cap can be budged. When soldering in a new cap, the solder doesn't adhere well to the solder pad; it only sticks to the cap lead, even though I had the iron's tip in contact with both lead & solder pad.

Does anyone have any suggestions? Pro289 wrote that he needed to drill out the old solder. That sounds scary if the drill is handheld (and I don't have a drill press)... couldn't a tiny accidental movement of the hand destroy the metal sleeve in the hole?

Thanks in advance for your help!

[MrNovi]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

Well, it ran StressCPU for two straight days without a glitch so it looks like it was a success. Thanks so much for all of the assistance with this guys. This forum is great.

[MrNovi]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

Getting closer. Replaced all of the caps, put it back in the case, hooked everything up, and it not only booted into the bios, but into Windows Startup Repair. I still have a lot of tinkering to do to fix her Windows install, but at least it's getting a lot further than it has in the past.

[MrNovi]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

Looking better. I replaced the two caps I had already removed and soldered the neg lead from cap with the damaged pad to the neg lead of the other cap after it was soldered to it's pad. I installed the cpu, heatsink, ram, psu, plugged it in and it not only powers up but goes into the bios screen which it didn't do when I got it. I'm going to continue with recapping the board later today, but things are definitely looking better now.

Thanks for all of the help ben. It is much appreciated.

[ben7]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

Thanks for the advice. I was thinking it was connected to an inner ground plane as it looked like the solder pad area didn't connect to any of the visible external traces.

So I could solder it to the negative pad of the cap that sits next to it (an 1800uf 6.3v) if I understand what you are saying correctly? I can identify that fairly easily. The hole is surrounded by two positive traces from what I can tell, so that would be easier that trying to reach one of the ground traces itself from what I can see. I could insulate the leads with some heatshrink tubing. I guess that the old saying that the mind is the first thing to go reared it's ugly head here as it never dawned on me to connect to another ground source.

I haven't replaced any of the other caps yet. In fact, I have only removed the one I ran into the problem with and the one next to it as I didn't want to waste any of the new caps on a lost cause.

I used to be better at this when I was younger. Age which has brought on arthritis and poorer vision makes working with smaller and more delicate items like this more difficult every day.

Sure, solder the negative leg of this cap to the neighbor capacitors' negative leg/pad. As you said, use heatshrink tubing! Also double check polarity of the capacitors, and check for visual short circuits near/under those capacitors before you try to turn the motherboard on!

Good luck!

[MrNovi]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

Thanks for the advice. I was thinking it was connected to an inner ground plane as it looked like the solder pad area didn't connect to any of the visible external traces.

So I could solder it to the negative pad of the cap that sits next to it (an 1800uf 6.3v) if I understand what you are saying correctly? I can identify that fairly easily. The hole is surrounded by two positive traces from what I can tell, so that would be easier that trying to reach one of the ground traces itself from what I can see. I could insulate the leads with some heatshrink tubing. I guess that the old saying that the mind is the first thing to go reared it's ugly head here as it never dawned on me to connect to another ground source.

I haven't replaced any of the other caps yet. In fact, I have only removed the one I ran into the problem with and the one next to it as I didn't want to waste any of the new caps on a lost cause.

I used to be better at this when I was younger. Age which has brought on arthritis and poorer vision makes working with smaller and more delicate items like this more difficult every day.

[ben7]

Re: ECS mcp61pm-hm 6-bad 1800uf 63 Tk caps

I tried doing that, but I can't see the trace the pad connected to.

Looked on both sides of the board?
If you can't see where it goes to, I don't think it would hurt to try powering up the motherboard( as long as all the other caps are in place.) The worst that could happen is there could be a short inside the pad hole.

It also might connect to an internal power plane.

Edit: WAIT, since it has happened to the negative lead pad, I would assume that you could just connect the negative lead of the new cap to the ground plane, wherever it is accessible. (It is probably a filter cap, because of its 1000uF rating)