How can I desolder chock coil in PGA370 socket mainboard

[bshi02]

Re: How can I desolder chock coil in PGA370 socket mainboard

I test all of my CPU and CMOS battery, pc100 RAM in other mainboard, confirmed that It surely works. So I installed these CPU,battery,PC100 RAM which I just have tested in other mainboard.
this mainboard(PYRAMID-5) doesn't have connector for PC speaker it only has led and power switch.(I only has PCB of front panel. I lost pin connector and currently I don't have it)


Frankly speaking this mainboard start to boot as soon as I connect PSU 20 pin connector to mainboard When I turn on PSU button.
But When I connect PSU 20 pin connector to mainboard as soon as I turn off PSU button, then I repeatedly turn on PSU button,It doesn't boot anymore.

From PCB of front panel I noticed that third row of solder joint is PSU switch, So I contact third row pin of mainboard connector with ground pin by screwdriver. But it doesn't boot at all..

I just realized that this mainboard is not for SAMSUNG MAGICSTATION of M5317 model but for MAGICSTATION M4325 model.

SAMSUNG MAGICSTATION typically doesn't have any mainboard manual, It only supports audio or graphic driver and booklet for drive installation.

I examined south and north bridge chipset and It is written that
intel R 810
FW82810DC100
F942TD07
SL3P6 intel MC 98
E9245476TA
942 KOREA

Intel FW82801AA
F947TC08
SL3MA
Intel MC98
KOREA

[bshi02]

Re: How can I desolder chock coil in PGA370 socket mainboard

I noticed that a small capacitor which foil was a little worn out. So I replace this capacitor and It has small solder pad and surrounded by too many pattern So I use BC1 solder tip in order to desoldering it,I set target temperature to 310 ℃. But It always takes at least more than 15 minute for me in order to insert a cap into solder pad. Because I don't have desoldering needle and don't have sufficient experience for any desoldering tool..It seems that small solder pad cannot tolerate 310 ℃ temperature that lasts more that 10 minutes..So I eventually burned up solder pad like below screenshot.



I'm sorry to say that It seems it is impossible to fix this PYRAMID-5 mainboard anymore...

[sam_sam_sam]

Re: How can I desolder chock coil in PGA370 socket mainboard

When you try this again set the temperature a little bit higher so that you are on a soldering joint pad for the shortest time possible if you are able to flow the solder to quickly

( on very small soldering joint pads)

then lower your heat setting if you are not flowing the solder quickly then you need to raise the temperature setting

if you are discoloring the board and it is a multi layered board with a ground plain then you are going to have use a temperature controlled hot air gun do not be tempted to use a normal heat gun for removing paint that would ruin your boards

The first thing you do is set your temperature controlled heat gun to the temperature that the solder begins to melt then switch to the soldering iron sometimes you will need to use both

Now someone mentioned about using a Desoldering gun I sometimes prefer to use this most of the time to reflow soldering joint pads after putting solder on the soldering joint pads to make sure that I have a good soldering joint and removing components from a board and sometimes you still need to use a temperature controlled heat gun for boards that have very large grounds plain areas

I set my Disordering gun temperature to 775*F yes I know what you are going to say that this temperature is very high and you would absolutely correctly however I personally found that when I have it set to this temperature I get on and off of a soldering joint pads very quickly and be done with it in the shortest time possible which is making perfect sense to me ( and on rare occasions I will set the temperature as high as 890*F when there are very large ground plains and there is a lot solder use for power supply wires )

One note this technique does not work for poorly constructed quality boards and when I see that the board soldering joint pads the board is discoloring or the pads are lifting off of the board I will drop the temperature by 100*F and see if it still discoloring the board if so drop it another 50*F until you are not discoloring the board but the solder will still melts and will still flow

One other note if you are doing mother board with hair thin wire traces with soldering joint pads you have to be extremely careful with this type of traces because you can ruin them as you have in countered

I have not really found a good technique for doing this type of soldering if someone would share a proven technique experience with very good professional quality please share how you can do it

Because my results are hit and miss and are not repeatedly all the time with the same exact results

[dicky96]

Re: How can I desolder chock coil in PGA370 socket mainboard

I set my Disordering gun temperature to 775*F..........

And how much disorder can you cause with that?

@bshi02
I use BC3 tip to desolder capacitors, not the BC1

Set the T12 soldering iron to 380C. Hold the board at an angle so it is about 45 degrees with the component side on the lower side

Get a big blob of solder on the BC3, then use it to heat both pins of the capacitor at the same time. You can then pull the capacitor out with your fingers.

Tell you what, I'll make a short youtube video for you on Monday and upload it, then you can see how I do it. I'm using the same equipment as you are so you should be able to learn from the video.

Oh did you get the NC-559-ASM flux I mentioned previously? It is going to help you a lot.

I don't think you trashed that motherboard. most likely that capacitor was from a power rail to ground. It's hard to see if you damaged the fine traces but it does not look like you did.

Regards your motherboard, yes it is very similar to the MS-6178 motherboard I am trying to fix at the moment. It has exactly the same chipset as yours. Mine also powers on and off from the front panel switch now, but it will not boot.

Originally it would not start - after I fixed that it would power on but not off, then I solved that problem. Now it powers on and off but will not boot. Here are two threads which describe how I have been progressing with this board - it is still not booting yet, but I believe I am getting close to understanding what is wrong with it.

Have a read through these threads - it will give you some idea of the type of faults you may come up against, and the tools you may need do these repairs.

https://www.badcaps.net/forum/showth...hlight=ms-6178
https://www.badcaps.net/forum/showthread.php?t=93613

[diif]

Re: How can I desolder chock coil in PGA370 socket mainboard

A K tip will also desolder both capacitor legs at once, and has a built in 45 degrees, so no need to hold the board at funny angles.

[bshi02]

Re: How can I desolder chock coil in PGA370 socket mainboard

@bshi02
I use BC3 tip to desolder capacitors, not the BC1

Set the T12 soldering iron to 380C. Hold the board at an angle so it is about 45 degrees with the component side on the lower side

Get a big blob of solder on the BC3, then use it to heat both pins of the capacitor at the same time. You can then pull the capacitor out with your fingers.

Tell you what, I'll make a short youtube video for you on Monday and upload it, then you can see how I do it. I'm using the same equipment as you are so you should be able to learn from the video.

Oh did you get the NC-559-ASM flux I mentioned previously? It is going to help you a lot.

I don't think you trashed that motherboard. most likely that capacitor was from a power rail to ground. It's hard to see if you damaged the fine traces but it does not look like you did.

Regards your motherboard, yes it is very similar to the MS-6178 motherboard I am trying to fix at the moment. It has exactly the same chipset as yours. Mine also powers on and off from the front panel switch now, but it will not boot.

Originally it would not start - after I fixed that it would power on but not off, then I solved that problem. Now it powers on and off but will not boot. Here are two threads which describe how I have been progressing with this board - it is still not booting yet, but I believe I am getting close to understanding what is wrong with it.

Have a read through these threads - it will give you some idea of the type of faults you may come up against, and the tools you may need do these repairs.

https://www.badcaps.net/forum/showth...hlight=ms-6178
https://www.badcaps.net/forum/showthread.php?t=93613

Thank you very much for all of your detailed reply which is a great help to me!
Of course I use BC3 soldering tip when I desolder or solder capacitor on mainboard.

But In this case of small solder pad which surrounded by several thin pattern, I firstly tried to desolder it with BC3 soldering tip, but its(BC3) tip size is too large, I think that As My soldering skill is still rudimentary, there would be high possible to damage nearby thin pattern with this BC3 large tip, So I changed soldering tip to BC1 and eventually burning this small solder pad...

I already have soldering paste of below screenshot So I thought that I don't have to purchase flux again


Of course,I would have been very delight if it was possible to fix this Pyramid-5 mainboard, But Now I think It would be positive experience for me even I eventually failed to fix this mainboard by burning small soldering pad.

[dicky96]

Re: How can I desolder chock coil in PGA370 socket mainboard

Hi diif
The reason I hold the board at an angle is so I can grab hold of the capacitor with my fingers and pull it out. It's probably held more towards upright on edge than 45 degrees. Also holding the angle means the big solder blob stays on the BC3. I've not tried a K tip for this, though I do have one. I can see how that would work but I do like the high thermal mass of the BC3 for this sort of work

@bshi02 - I have no idea on that flux, you could ask in the soldering techniques forum section https://www.badcaps.net/forum/forumdisplay.php?f=33
I tried several types before the NC-559 but now I stick with that one. Actually I think it was diif who put me on to it

[ChaosLegionnaire]

Re: How can I desolder chock coil in PGA370 socket mainboard

It always takes at least more than 15 minute for me in order to insert a cap into solder pad. Because I don't have desoldering needle and don't have sufficient experience for any desoldering tool.

just use a safety pin or sewing needle to clear the holes. im sure your mom should have safety pins or sewing needles lying around the house. use pins or needles that are 0.5mm or 0.6mm in diameter. the lead diameter of capacitor legs are around that size. however, the important thing to note is that u should make sure the needle or pin is made of stainless steel so that the solder wont stick to it. otherwise, u might solder the needle to the board and it will get stuck/jammed in there.

It seems that small solder pad cannot tolerate 310 ℃ temperature that lasts more that 10 minutes..So I eventually burned up solder pad like below screenshot.

I'm sorry to say that It seems it is impossible to fix this PYRAMID-5 mainboard anymore...

ummm... thats not the way to solder! u are supposed to heat up the pad for 10-20 secs max to melt the solder and then remove the heat. u're not supposed to heat up the entire board by leaving the soldering iron/gun on there for ages!! not to mention, caps dont tolerate heat too well. the high heat from the soldering iron can damage the caps. therefore, dont heat up the caps for too long when soldering/desoldering.

once again, proper equipment to do the job matters. get some stainless steel safety pins or sewing needles of 0.5-0.6mm in diameter to clear the holes so u can put the caps in properly this time!! it also helps to take extra care when soldering/desoldering pads that are near/around traces. so anyway, even if u cant fix it, just take it as extra soldering practice and experience. also try to see if u can get junk circuit boards like faulty/dead motherboards to practice soldering/desoldering on.

lastly, sorry to hear about your father. i appreciate u understanding the situation now and taking charge now that u are the man of the house after your father has passed and u want to now take charge of your life after throwing it away into video games. so i wish u haeng un eul pibnida (good luck in korean for those who dont speak korean) in your endeavours and do let us know if there is anything else we can do to help u.

[dicky96]

Re: How can I desolder chock coil in PGA370 socket mainboard

OK I promised to upload a video showing how I replace capacitors on motherboards. Normally I would use my electric vacuum desoldering pump plus hot air, but I wanted to show how to do it with more basic equipment

This is the first time I have tried making an educational video so please excuse the bad camera angle - I will learn to do better next time. Also at one point I refer to the solder I am adding as 'lead free'. It is not, it is 60:40 leaded solder

Anway I hope this helps bshi02, and anyone else learning to do this sort of repair.

https://youtu.be/f_-GfrQHkjc

[bshi02]

Re: How can I desolder chock coil in PGA370 socket mainboard

Thank you very much all of reply!
I saw youtube video which created by dicky96,Although I'm really useless at hearing english,I understand to a certain degree How to desolder and recap with basic soldering tools.
I have used dressmaker Pin for making hole in solder pad.

But I always place soldering iron to opposite side of PCB because solder pad is too small for me to place soldering iron and dressmaker Pin together..


And As for Pyramid-5 mainboard,I have tried to replace all of capacitor which volume is more than 100uf So I recapped all of 1500uf capacitor and most of 220uf capacitor But It won't solve the problem of black screen and no beef sound, and problem of automatically turn on when I connected PSU power cord.
I think that real problem is not capacitor but problem of other IC part and I saw below link which testify that it is possible to solve no POST mainboard with reflow.

https://www.badcaps.net/forum/showth...aps#post187665

But I don't any type of heat gun and my current situation is worse than before. My mother cannot endure smell of soldering any more And said that It make seriously worse her chronic illness of dizziness and request me to totally throw up any soldering and looking for other job which don't need to practice soldering in house...
hah... It is another curse to be born in the parents who hate and don't know anything about soldering, not to mention to be born in goddamned south korea

[ChaosLegionnaire]

Re: How can I desolder chock coil in PGA370 socket mainboard

reflow wont necessarily fix the no-post problem. the reason why it worked in that thread was because the chipset on the board was a nvidia chipset which has known overheating problems that a reflow *may* sometimes fix but not always.

i've not heard of the intel 810 chipset and ich1 or ich2 southbridge having bga solder issues that a reflow would sometimes fix. the problem lies elsewhere. from the symptoms u said of the board having issues powering on and off and not booting, maybe the issue lies with the super io chip of some sort or somewhere there. maybe the rtc crystal pll chip is focked also.

My mother cannot endure smell of soldering any more And said that It make seriously worse her chronic illness of dizziness and request me to totally throw up any soldering and looking for other job which don't need to practice soldering in house...

i dont recall soldering making that much bad smell and stink. its not supposed to do that or be like that. make sure u arent overheating the board by putting the soldering iron on for too long and burning it, causing a bad burning plasticky smell to be released and yes, that is smelly...

[dicky96]

Re: How can I desolder chock coil in PGA370 socket mainboard

I second what ChaosLegionnaire says. You need to diagnose the fault, not just heat things up in the hope that will fix things.

I already gave you a lot of information as I have been trying to fix a very similar board to this (same chip set for sure, possibly same SIO (Super IO chip) as well


https://www.badcaps.net/forum/showth...hlight=ms-6178
https://www.badcaps.net/forum/showthread.php?t=93613

If you follow through my attempts to fix a non booting board you will very likely find that checking for the same problems will give you a good idea where the problem lies on your board. Also the Schematic I posted my be very similar to your board, so have a look.

Specifically do the following, in this order:
1. Is there any voltage on the pins to the PS_ON switch? if not let us know. If there is then...

2. Get a PCI POST analyzer card - stick it in the motherboard and see if anything is happening. Let us know any codes you read on the analyzer card. if it is reading 00 or some other random static number then check the following (step 3 onwards) . If it is running round in a loop of codes, or shows various codes then lock up, let us know.

3. Is the RTC crystal oscillating (for this you are going to need an oscilloscope - I can't think of any other way to test it - maybe others can, Possibly you could use a multimeter with frequency counter built in, though I never tried that as I have several oscilloscopes. The RTC crystal will be a little cylindrical crystal near the ICH.

4. Check all the output voltages on every voltage regulator on the board, make a note of the voltages. Identify the voltage regulator chips by googling for DATASHEET + the part number.

5, Is the signal PWRGOOD asserted high? You can probably find where to measure this by studying the SIO and ICH chip set datasheets, it's easiest to measure at the SIO - which is probably the same SIO chip as on my board (see above threads) so I could have done a lot of work for you

6. Is the Clock Generator / PLL IC working (gonna need an oscilloscope for this 100MHz bandwidth). Find the chip from it's part number and google for datasheet, then check all the clock output pins.

7. Is the signal *PCIRESET (*PCIRST) high? - This signal is generated by the ICH and you can probably check this from the reset pin in the PCI slots. It should be high, and go low when you press the Reset switch (assuming your board has a reset switch pin header) . While you are at it, check if there is any voltage on the RESET switch header pins? If not let us know.

8. If *PCIRST is High, check *CPURESET. This signal is generated by the PCH and best place to check it is to first measure resistance from the reset pin on the CPU socket (again my thread will help you) and find where it connects to one of the little resister networks (RN) near the CPU socket. once you figure which RN pin it connects to you can check it there. If you have one of the black PIII CPUs with silver connections all over it, you can check CPURST* directly on the CPU instead. If it is low then the CPU is stuck in reset.

So this is the sort of process you need to be following if you actually want to learn motherboard repair. You are going to need the equipment to do this sort of work, there is no way around that.