My first recap -FAIL! Please offer advice.

[Agent24]

Re: My first recap -FAIL! Please offer advice.

My multimeter was the cheapest one available from Dick-Smith. Normally $30 I got it for $20 on special.

So that's about $15-$20 US, I guess.

A cheap one will be better than nothing , but try to avoid anything _really_ cheap (say from a local Chinese shop for $2.50 or something)

Something cheap from RadioShack should be OK, but you might be able to get a good deal for a better meter 2nd hand on eBay or something. Garage sales where people don't know the value of things are always a good place if you get lucky

[Davisdog]

Re: My first recap -FAIL! Please offer advice.

bigbeark,

I did test it outside of the case, sitting on cardboard. Same deal. I'm using a 30 watt pencil style iron, from Radio Shack. One of the legs of the problem cap had broken off inside the hole. I had a heck of a time getting it out. When I was done, the hole looked pretty nasty. I have already tried reflowing it, along with all the rest, but there was no change. I didn't mess with the other poly's at all.

I don't have a multi-meter, so all I've done is a visual inspection. I would like to get a multi-meter, but my repair budget is getting pretty thin. My wife is getting to the point where she wants me to just go buy a whole new computer. I would like some recommendations on affordable meters though.

[bigbeark]

Re: My first recap -FAIL! Please offer advice.

Ok, I looked everywhere for a short. I couldn't find one, but there is a nasty area around where I struggled to get out one of the old poly's (I left the other two old poly's after that experience.) Some of the green is scrapped off in that area, but upon close inspection, there does seem to be space between the solder and the scrapped off area, so I'm not sure that's the problem. I am concerned about the internal damage I might have done there..

When you say struggled to get out, what actually happened. Did you really yank on it?
Did you try to remove the other 2 polys? What size iron are you using? It's possible you could have broken the connection inside one of the other polys if you tried to remove them.

Whichever cap refused to slide out easily is probably the one causing the problem. Try reflowing that one.

Please test the board out of the case, see if that makes a difference. You've got a lot of excess leg-length on some of those caps, could be shorting to the case.

[Agent24]

Re: My first recap -FAIL! Please offer advice.

Have you actually tested for shorts with a multimeter or just looked for them with your eyes?

There could be stuff going on between the underside of the capacitor and the board, where you can't see it..

[Davisdog]

Re: My first recap -FAIL! Please offer advice.

Ok, I looked everywhere for a short. I couldn't find one, but there is a nasty area around where I struggled to get out one of the old poly's (I left the other two old poly's after that experience.) Some of the green is scrapped off in that area, but upon close inspection, there does seem to be space between the solder and the scrapped off area, so I'm not sure that's the problem. I am concerned about the internal damage I might have done there.

Attached are some photo's before and after the surgery. I hope they show enough detail, as they are the best I can do right now. I'm having camera issues that rival my computer issues at the moment. The first three photos are pre-op, the rest are post-op (maybe post-mortem.)

I did try the power cable suggestion - no difference. I tried it with one and two fans, with and without: memory, HD, processor, and just about every combination of all of that, it keeps doing the same thing.

[kaboom]

Re: My first recap -FAIL! Please offer advice.

I almost thought I trashed this one board. Intel OEM for Dell.

Got all the nasty old caps out in the VRM and ohmed out Vcore and 12Vin to the ground plane. Dead short on 12Vin. Here it was- this little solder splash from the hole of one of the 12v caps right to the ground plane. Looked close and found it. Pulled it off with solder wick and no more short. I thought one of the layers was shorting to a via...

Replaced ALL caps and perfection! When I got it, no boot, no nothin. I wasn't stupid enough to 'just try it,' as I saw the craps, both on the board and in the PS. People were blaming software as usual. And just how does software cause no power?

That thing booted right up like nothing was ever wrong. It did get the ol' format n reinstall, since some people 'mistreat' their computers.

All you have now is basic electronics troubleshooting- looking for that short. It's not any different because you're inside a computer. You'll find it.

-Paul

[Agent24]

Re: My first recap -FAIL! Please offer advice.

I thought an iron like that could damage the board too easily?

[kiddznet]

Re: My first recap -FAIL! Please offer advice.

I'm with bigbeark
This bad boy 80W iron has them caps jumping off the board in fright
Easy to put them back on with it as well gives a nice neat pro looking job.Clip the cap legs before fitting

http://www.jaycar.com.au/productView...n&form=KEYWORD

[bigbeark]

Re: My first recap -FAIL! Please offer advice.

I did have some trouble getting some of the old caps off and I admit I may have jacked up this board.

If you had to pull hard to get the cap legs out of the holes, you may have dislodged an internal trace or "via".

Before removing caps you should apply fresh new solder The remelt the joint and work the capacitor back-and-forth until one leg comes out, then reheat the other leg and do the same until it comes out. For best results you need a good-sized chisel tip, at least 1/8 inch and an iron of 50 watts or better.

Newer boards are much harder to work on because of the no-lead solder.

The cap legs should slide out of their holes easily, with no feeling of pressing hard on the cap.

[Davisdog]

Re: My first recap -FAIL! Please offer advice.

No caps in backwards. I made a chart before I began and checked it several times both during the surgery and in post-op. I verified before I began that the half-moons indicate the negative side on all of the caps on this board. I actually printed out one of c hegge's photos of his board and marked it up as my road map.

[kc8adu]

Re: My first recap -FAIL! Please offer advice.

any caps in backwards?

[Davisdog]

Re: My first recap -FAIL! Please offer advice.

Thanks for the replies. I have just finished looking over the mobo for obvious shorts. I couldn't find any, but there are two very small suspect areas that I'm gonna give some attention to tomorrow evening. After that, I'll try running it without the 4 pin connector as c hegge suggested.

One thing I'm concerned about: I don't have any alcohol or flux cleaner, so my solders look pretty nasty right now. Will the burnt flux cause any problems? Also, will stray solder that is not touching any terminals cause any problems (like just in a random spot on the green pcb, but not touching any exposed metal?) I don't see any of that, I'm just curious.

I will try for some photos tomorrow night if the above does not work.

Davisdog.

[c_hegge]

Re: My first recap -FAIL! Please offer advice.

Try unplugging the 4 pin CPU Power connector. If it stays running like that, then the problem has to be around there. As seanc said, a shot of the board would be helpful.

On a side note, I've re-capped four of these exact boards so far and in each case, I've used polys around the CPU and it's worked every time. In one case, I even replaced the 3 1800uF 16v lytics with 470uF polys and it worked. Therefore, the poly mod itself wouldn't be the problem.

[seanc]

Re: My first recap -FAIL! Please offer advice.

Can you post pictures of your work so we can check for any accidental polarity swaps etc.

[yyonline]

Re: My first recap -FAIL! Please offer advice.

The symptoms you describe - powering on briefly and then power cutting out - can be caused by a short. When the power supply detects a short, it cuts power to the system. I'd pull the board out and very carefully look for any stray bits of solder that may have shorted something out. Hot solder can "jump" impressive distances while you're working, so be sure to look everywhere on the board.

[Davisdog]

Howdy all,

I've been lurking on this board for about two weeks now. I've read a ton of posts here and elswhere on the web.

My mobo, a ECS HP MCP61PM-HM, out of a Compaq desktop had several bad caps, the identical situation as https://www.badcaps.net/forum/showthread.php?t=12149. I've read that thread several times and used the info there as the basis for my recap.

I got my new caps in a couple days ago (from Badcaps) and have since installed them. Taking a lead from c hegge, I went with polys next to the processor.

Prior to this project, I've been getting a lot of BSOD's. Sometimes the system would randomly reboot itself, sometimes just the BSOD and I would have to manually reboot. This started happening more and more often, until a couple weeks ago when during a startup, it got to the POST screen and the video went kind of crazy, with lots of goofy stuff all over the screen, then it locked up. After that, it fired up and sounded ok, but no video.

I took it in to the Geek Squad. They weren't able to get it to work (no charge for the diagnostic). They even tried a brand new video card (I was hoping that was the problem) but no-go. Those guys pointed out the bulged caps to me. That is what got me to this website.

Before I replaced the caps, the fans would spin whenever the power was on and the computer made all the normal beeps and such, just no video. After the cap job, it powers on for about 1/2 second, with all of the fans spinning, then it cuts off. No beeps, no video.

I haven't got a clue what I did wrong. I did have some trouble getting some of the old caps off and I admit I may have jacked up this board. After it didn't work when I put it back together the first time, I pulled it out and re-heated all of the new solder joints. Still no-go.

If anyone has any advice as to what I should try next, please help. If I can't get this going in the next day or two, I'm thinking I should just replace the mobo with a new one. If I go that route, I'll be looking for some help in that direction as well.

I appreciate your help!

Davisdog.