I need pictures of t41 mainboard bottom side (gpu area)!

[juhpal]

Hello,

I did the gpu soldering with heatgun and almost everything went well, BUT:

There is a quite small plastic tape on the bottom side of T41 mainboard next to the place where gpu is. And this tape heated up and curved. It took a few smd components off the board. I resoldered most of them, but I need a confirmation that they are right.

Could someone be so nice as to post high resolution pictures of the gpu bottom side area with the plastic tapes removed? The critical area that I need is next to the cd/dvd-rom ide connector!

[rkawakami]

As I have a vested interest in also getting this information (I'm planning to do a re-flow on a T41 motherboard as well), here's a fairly detailed scan of that area from a 93P3307 board:

http://www.kawakami-ca.com/ibm_t41/93p3 ... pe_720.jpg (913KB 1600x1900)

If you need more detail (or less) of that area, or any other place on this motherboard let me know.

edit:

Note: After posting my scan I almost immediately got a PM from sojourner about what looks like a cracked or partial component near the "1 Y1" (about 1/3 the way up the image, left of center). The part is whole; what you are seeing on the scan is some glue residue on top of the part. The scanner's light is reflecting off the surface and makes it appear darker than the rest of the top. You can see the same thing on Q92.

[sojourner]

As I have a vested interest in also getting this information (I'm planning to do a re-flow on a T41 motherboard as well

Same here Ray (T41 also).

juhpal, I'm wondering if you could provide a little more information about your process. This information could be valuable to many forum members, such as myself, Ray etc who are facing the PLAGUING ATI GPU problem and wanting to correct it.

Could you tell us if you used a digital thermometer? If so what temp did you bring the GPU up to? Did you shield everything around the GPU with foil? Lastly, how do you figure the capacitors dropped off the bottom?

[richk]

you would be more likely to get helpful pictures if you included the fru of the board

[juhpal]

Hello,

Thank you very much for the fast response, this is great forum! I did it at work (I work in a power supply company) and used a thermocouple to measure temp. I also glued the thermocouple with fast glue, but it came off during the process, because 250-300 degrees celsius is too much for almost any glue

I followed the example in the two youtube videos:
http://www.youtube.com/watch?v=vR8L3B3e ... re=related
http://www.youtube.com/watch?v=zyoFuL0YRac

I think that if you follow the same videos and use max temp around 260-300 degrees celsius (measured on the PCB), you will be OK. The real reflow process is very accurate, but I think that the components will handle the stress if you do it about right with heatgun. (heat quite slow, but don't keep the high temperature too long, let it cool down quite slow, timeline same as in the youtube video)

I practiced first with a spare PSU PCB to see what is needed to reflow the components with heatgun. I advice to reflow some broken PCB (or some T4x board if you have spare to practice the process. I covered almost the whole PCB excluding the GPU with aluminum foil.

Too bad I didn't take off the tape!!!! GRRR. I guess the board would be working already without that mistake. So TAKE THE PLASTIC TAPE OFF (near GPU) BEFORE REFLOWING!!! Also be careful: When the board reaches 230+ degrees celsius, the components might move if you blow the heatgun too near them, so keep some distance or use slow blowing on the heatgun.

rkawakami, thank you very much for the picture! I have too 93P3307. However there are slight differences (or i have lost some components). I modified your picture a little:

http://koti.mbnet.fi/~juhpal/marked.bmp (sorry to use bmp format... I did it quick)

The components marked in blue in the picture above came off the board. The plastic tape was glued to them, so they just came off glued to the tape (that is how I managed to save the components, I hope:) Other components stayed on place (and all will stay in place if you take off the tape).

In my board there are no soldering taps in place of diode(?) 1. I think I have lost component 2 (transistor or diode?) or most likely didn't have it in my board? Can someone check his/her board for this component 2, what does read on it?

Also if someone could use multimeter to measure resistance (or use bleeper) between the red dots I have marked on the picture? My board reads 0 ohms... I think there is a short somewhere.

Thank you for the help!

[sojourner]

juhpal, I too have a FRU 93p3307. It looks just like Ray's (great) picture ... so you are missing components. Being these are BLACK and about the size of a flee, did you look closely on the tape to see if they are stuck there? Did you check the work area for the tiniest bit of a black spec? Hope you'll fine them, and if not there may be someone to pass parts along from a trashed board or perhaps you can even buy one cheap (with bad GPU) and use it for parts!

Checked resistance you wanted, it's 800 ohms.
Component #2 has a number: 29

[juhpal]

juhpal, I too have a FRU 93p3307. It looks just like Ray's (great) picture ... so you are missing components. Being

I really hope that I'm not missing any parts... The weird thing is this. Look the picture below:

http://koti.mbnet.fi/~juhpal/routing.bmp

The routes marked in light blue are the routing on my board (some other layout version?). I don't have a place for component #1, there are no taps! However I have a component looking just the same as #1 and I don't know where it belongs. I don't have component #2, but there are thee-legged solder taps there... It seemed at first, that the extra component (diode?) that i have belonged to the place #2 (came off from that place?), but that component is three-legged and I have just two legged diode as an extra...

these are BLACK and about the size of a flee, did you look closely on the tape to see if they are stuck there? Did you check the work area for the tiniest bit of a black spec? Hope you'll fine them, and if not there may be someone to pass parts along from a trashed board or perhaps you can even buy one cheap (with bad GPU) and use it for parts!

Checked resistance you wanted, it's 800 ohms.
Component #2 has a number: 29

Thank you! Oh man... This means that I have a short as I expected. I will try to repair it for a while, but I might need a new board If someone has the same routing as I in my board, please let me know.

[sojourner]

juhpal, why don't you post us a closeup snapshot of your board (for that area).

Looking at this MOBO, for that area, solder pads are not tinned unless a component was mounted. Thus it should not be hard to figure which parts go where ... but we need a pic of YOUR board!

Regarding the short at Q55, some thoughts:

1. improper soldering of reinstalled components? (traces shorted)
2. heat damaged component caused failure, thus short

(BTW, for others following this thread, do NOT bring your temps over 255c when reflowing because most components cannot handle temps over 260c for very long without damage. I would reflow at 250c, hold for no more than 5 seconds)

3. diode mounted in wrong direction
4. solder balls under Intel North? South? bridge have shorted (possibility because the short is in proximity of that BGA)

----

misc notes:

- component #1 appears to be a diode (determined bywhite band)
- the only other components there are resistors (solid black rectangles, two contacts), capacitors (tan, two contacts), transistors? diodes? with three legs

If you can post a PIC I think we'll be more likely to be able to help.

BTW, regarding the different routing, yes we may have different rev. boards

[juhpal]

I haven't posted a pic, because my digicam is in another city... I will try to take a pic today at work.

Yes, it is possible that I shorted some components, because I didn't use any magnifying glass etc (was in a hurry... shouldn't have been)

I used ~280 degrees celsius just to be sure that everything soldered. (I didn't have anything to lose, it would be nice to get this MB working, but not very necessary, a radeon 9600 board would be nicer.) The lower temp is ok if you want to be careful (and usually you want .

Yes, it shouldn't bee too hard to figure the placement of the components. I will try to post a pic later today!

[juhpal]

OK, here is the pic of my mainboard (bottom side gpu area):

http://koti.mbnet.fi/~juhpal/Picture%20014.jpg

I took away a few capacitors hoping that their bad soldering would have caused the short (caps to the left from marking q55 are removed in the picture). There is also one diode that is extra.

http://koti.mbnet.fi/~juhpal/Picture%20024.jpg

I know where the caps belong but I don't know where the diode on the right belongs. Thanks again for the help!

[Harryc]

The area to the right of 092 as marked on your board looks borked. I'd go for a new board.

[juhpal]

The area to the right of 092 as marked on your board looks borked. I'd go for a new board.

Yes, it looks bad, but the connections are OK If I just could find the short circuit there would be a good possibility to get this working!

[Tim M]

The area to the right of 092 as marked on your board looks borked. I'd go for a new board.

Yes, it looks bad, but the connections are OK If I just could find the short circuit there would be a good possibility to get this working!

The solder bubbling through some of the holes to the left of the "Q55" marking is another area of concern.

[sojourner]

Don't see anything that should not be able to be fixed. Saw the area to the left of Q55 where the (3) caps go. The thing you said is a diode ... not sure about that ... not sure that's what it is and see no place for it. There IS a spot where it looks like a transistor(?) is missing. It is to the upper right of Q92, three pads where our MOBO's have a transistor/diode(?) mounted ... but you don't have one of those as extra parts? Are you sure the 'xtra' component you have is not a three legged component (hard to tell from the pic)?

If you are equipped and willing to put in time, you might want to clean up some of what looks like solder spatter (soft tooth brush or Q-tip and rub gently ... little Isopropyl), blow it off and double check what's been reinstalled to insure no shorted pads, traces. If it helps, I use a grounded low watt soldering iron (20 or 30 watt) and TIGHTLY wrap a piece of solid copper electrical wire around the tip, it has a sharp point filed or ground onto the end. This gives even less heat to the new tip and gets right in there for those smaller than a flee sized pads! It's great for installing SMC as well as removing. Another tip I've come across, it sometimes helps to use a little superglue with a tooth pick to stick the component in place, then solder. Sometimes you can get away with holding it in place with a toothpick, then solder.

In my old age have also found it VERY helpful to have an Optivisor, magnifying glass, eye loop and BRIGHT light on the desk for this type work. Works wonders to get the job done!

Last comments:

The solder blob by Q55, was that from your iron or spit from the BGA above?

Also with regard to Q55, when I tested I checked for RESISTANCE, not continuity. There is continuity (a bleep as you say). Resistance is approx. .8K

Won't be around again for the next day and a half or so. Hope more of the other guys will jump in there, I know we have technical guys visiting (and I'm just a hobbiest), we encourage your input.

Basically sounds like we need to figure out where the 'xtra' diode goes and why there isn't a three legged component for the three vacant pads mentioned above.

Hope you can get this back up and running soon!

[Tim M]

Also with regard to Q55, when I tested I checked for RESISTANCE, not continuity. There is continuity (a bleep as you say). Resistance is approx. .8K

Hmm..800 ohms is too high to be a simple short.

...three legged component for the three vacant pads mentioned above.

I wonder if this component could be a voltage regulator of some sort.

[juhpal]

Don't see anything that should not be able to be fixed. Saw the area to the left of Q55 where the (3) caps go. The thing you said is a diode ... not sure about that ... not sure that's what it is and see no place for it. There IS a spot where it looks like a transistor(?) is missing. It is to the upper right of Q92, three pads where our MOBO's have a transistor/diode(?) mounted ... but you don't have one of those as extra parts? Are you sure the 'xtra' component you have is not a three legged component (hard to tell from the pic)?

Yes, I still think that this MB can be fixed I was out of town for weekend so that's why no update. Caps are OK (measured them) and I will re-solder them soon. The extra part on the component picture is definitely a 2-legged diode (measured it too, OK). But yes, there is a place for 3-legged component, but I only have that diode (2 legs)... If someone else with similar motherboard like my board could help??

If you are equipped and willing to put in time, you might want to clean up some of what looks like solder spatter (soft tooth brush or Q-tip and rub gently ... little Isopropyl), blow it off and double check what's been reinstalled to insure no shorted pads, traces. If it helps, I use a grounded low watt soldering iron (20 or 30 watt) and TIGHTLY wrap a piece of solid copper electrical wire around the tip, it has a sharp point filed or ground onto the end. This gives even less heat to the new tip and gets right in there for those smaller than a flee sized pads! It's great for installing SMC as well as removing. Another tip I've come across, it sometimes helps to use a little superglue with a tooth pick to stick the component in place, then solder. Sometimes you can get away with holding it in place with a toothpick, then solder.

Thanks for advice!

In my old age have also found it VERY helpful to have an Optivisor, magnifying glass, eye loop and BRIGHT light on the desk for this type work. Works wonders to get the job done!

Last comments:

The solder blob by Q55, was that from your iron or spit from the BGA above?

Yes, those are from my iron (and all the other mess:). But I think I didn't cause a short, but I have to double check it...

Also with regard to Q55, when I tested I checked for RESISTANCE, not continuity. There is continuity (a bleep as you say). Resistance is approx. .8K

OK, that gives some hope... But my multimeter measures almost 0, so maybe there is a short At least I think/guess that the BGA chip (northbridge) is OK with no shorts. (I hope.)

Won't be around again for the next day and a half or so. Hope more of the other guys will jump in there, I know we have technical guys visiting (and I'm just a hobbiest), we encourage your input.

Basically sounds like we need to figure out where the 'xtra' diode goes and why there isn't a three legged component for the three vacant pads mentioned above.

Hope you can get this back up and running soon!

Thanks for encouraging, I won't give up yet. But now It would be helpful, if someone figured a place for that small SMT diode on the right in this picture:

http://koti.mbnet.fi/~juhpal/Picture%20024.jpg

I guess if no-one won't find a place for it, I will try to boot the board without it There is a small chance it will work partly

[juhpal]

Hello,

Tried to boot the mainboard today. Got smoke -> Time for a new mainboard. I hope that the processor didn't toast... So there was a short in the northbirdge. Be careful when reflowing these boards!

[sojourner]

Sorry to here about the board, you put a lot of effort into repairing it. At least it has been a learning experience for us and this thread can help others in the future (the GPU issue has become sooo big). Thanks for sharing your experience!