Resistor Solder moved

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FaKringle

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Aug 8, 2002
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I got a mobo from a friend who did not coll his mahcine properly. Two of the resistors have been moved from their location.
The board is a: MSI K7T Pro2-A
the resistors which have moved are:
SUB75N03
09P
M08BHF

One has a small crack on it, the other one looks fine, but they have moved from their location on the board and one of them does not make connection to the board anymore. It has two legs which connect to it.

My question is, can this be fixed by getting two resistors and soldering them back to the location? The board is not fryed from what I can tell and it is in good shape. No burns or anything. Can it be saved or is it a waste of time?

Thank you!
 
From what I understand, yes.
He turned on the computer when he put it together and it started smoking in that area. It was not on for too long but it did move the resistors. Now from what he tells me it was because he did not have the fan on correctly on the CPU.
If I can find a picture of the resistors on a website I'll post a link to it.

Thanks.

EDIT:
I found a PDF which shows the resistor:
http://www.vishay.com/document/70745/70745.pdf

It's the one in the middle that says "TO-263". This thing worth salvaging?
<P ID="edit"><FONT SIZE=-1><EM>Edited by FaKringle on 10/28/02 07:29 AM.</EM></FONT></P>
 
2 things

1. What motherboard was he using? Arent those things usualy further away from the socket? In that comming lose, did anything else come off?

2. I have seen this happen before, but not for the same reason. A coworker of mine heard a loud pop in his machine, which caused it to freeze and never turn on again. Upon closer inspection, we found a part (similar to what you have there) at the bottom of the case. Another coworker, an robotics and circuitry engineer, suggested that when the part was soldered on origianly, the wave of solder (typicaly how boards of any kind are manufactured) the solder did not come into contact completely with the pad where the part attaches. This or just a dirty spot on the pad causes the solder to connect, but leave a pocket of resistance there. Resisance causes heat, and after long enough, the solder there melted, shorted and sparked, causing the spark (and mobo failure).

So, if you know what you are doing and can get a replacement, anything can be worth a shot, I would just wonder how much more is dammaged, if at all.

Added:

BTW, if he did not have the heatsink on correctly, the CPU would be toasted (or close to it) not parts on the board. That sounds like a faulty board. If it is new, return it.
You dont have an <b>ANY</b> key? Your keyboard must not be Windows XP certified...<P ID="edit"><FONT SIZE=-1><EM>Edited by Lonemagi on 10/28/02 01:31 PM.</EM></FONT></P>
 
1. Motherboard: MSI K7T Pro2-A
Nothing else came off. Everything is there and the board has no damage other than those two resistors moving.

Well from what I understand, the computer was not on for more than 10 secs, he saw the smoke and turned it off, never to turn on again. I have no idea if the CPU is bad or anything else is. I just want to see if I can salvage it and make it work. If I can fix it for ~$10-20 then I'm going to do it.

So lets say I can get those resistors out, how can I get them to stick if it is going to get hot again? I dont want them to move again if I solder them. Anything I can use? Any solder or is there a specific type? How can I clean the pad so its not dirty?

I used to solder a long time ago for fun and taking things appart and putting them back together. Its been a while.

Thanks for your input.
 
Um, that device in the pdf file is actually a MOSFET not a resistor. It is probably part of the regulator circuits (best guess since their location wasn't given). Usually they do not get near hot enough to melt solder since they are running in switching mode. It is possible that one or more of the leads was either soldered poorly or not at all (just the pin and the pad touching but not actually soldered together).

If it is a voltage regulator, then more parts may be bad, depending on which pin(s) were disconnected.
 
Hmm well I'll do this. I'll take a picture of it and post it. That will clarify things a bit. I got a usb cable now so I'll do it tonight.

Thanks again.
 
Being a electrical technician, I suggest that you take it to a qualified electronic repair technician, preferably at a major computer outlet. There could possibly be other faulty parts that supply this component. In my opinion, once a board has been damaged, it will in most cases break down again after a short period of time, because other components have been overloaded and weakened. Therefore, if the quoted repair cost is more than 20% of the board value, scrap it.

DCB_AU
 
Lol, that sounds like the sort of thing you hear from warranty booklets.

' NEVER attempt to open the case of your product. If you feel that your product is not operating correctly, take it to a qualified Gigabyte dealer or return it to us for a full inspection'

lol

My sig's faster than yours, and it overclocks better too....
 
Okay there is a picture here:
<A HREF="http://www.villagephotos.com/viewimage.asp?id_=913733&selected=105397" target="_new"> Lazy Link </A>

The picture is not the best but you can see two sets of the things that moved. Its not touching anything else. Anyone know what these resistor/transistors do?

Thank you for your help!
 
Those are probably voltage regulators. From the looks of it, there was shorting of one or more supplies in the past. When a supply is shorted out the regulator does what it can to supply current at the regulator voltage, even if it means getting hot enough to melt solder.

I would just remove them clean up the mess and try to put them back on. Chances are they saved themselves from death by removing themselves from the circuit by melting the solder. Something like that would be easy to find replacements for even if they are dead.

BTW I find it very hard to believe that everything was hooked up properly when this happened.
 
I have no idea what he did.
I'll remove them and get replacements. Do you have any idea where I can get something like this? Can I get it at a regular electronics store? Radio Shak or something of the likes?

Thanks again
 
Rat shack might have it in a local store,or might have to have it shipped from the supplier. I have had good results using digi-key mail order stuff...Good Luck

If ya don't ask..How ya gonna know.
 
I might be able to help you get started if you can still read any numbers off the parts and post them.
 
They are on the 1st post:
SUB75N03
09P
M08BHF

That's what it says on the top of the little chip things. I'll try to get a better picture. Those are horrible, but prove the point.

Thanks for your help.
 
SUB75N03 weird, they are fet's. TO-263 package. Vishay and General Semiconductor both make crosses. Mouser has them, digi key doesn't. The General version is only $2.03 when purchased individually. For some reason the Vishay part is $7.94.

Go with the General one to save a couple bucks. Be sure to tell the salesperson you NEED the TO-263 package.
 
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