FETs soldered or glued on board?

[AKBessy]

I have an Micro-Star MS-6312 Ver:1 board with some bad capacitors. I am trying to determine how to get the FETs off that are near the DIMM slots, so that I can test them for shorts. Can anyone tell me if these are soldered on or glued on? They don't look soldered on to me, so I thought I better ask.



(P.S. thanks for these boards - great learning opportunities are within these pages!)

[kc8adu]

Re: FETs soldered or glued on board?

with the leads pointing toward you check between the tab and right lead.
if no short or low resistance ok.
they are soldered.
no need to pull them unless one tests odd in circut.
a dead short between source and drain is most common failure.
welcome to badcaps!

[AKBessy]

Re: FETs soldered or glued on board?

Thanks kc8adu for the reply. I am happy to hear that I don't have to pull them to test.

One more question about how they are attached: I see another spot on the board that looks like a mounting pad for a chip or fet - no holes, but the whole pad is metallic with three metallic leads built in the board. Are some of these FETs mounted by putting a drop of solder on the board and placing the chip in the solder while it is still liquid - like tacking it on?

[kc8adu]

Re: FETs soldered or glued on board?

no the board gets a screen applied like silkscreening a tshirt.
solder paste is applied and then a pick and place set the parts.
board goes thru a vapor phase or ir relflow to finish the job.

[AKBessy]

Re: FETs soldered or glued on board?

Thanks for explaining that kc8adu. Last thing - I don't know what happened to my picture; can one of the mods fix the big gaping hole on my first post so that it is gone? Hehe, it is distracting!

[AKBessy]

Re: FETs soldered or glued on board?

Thanks for explaining that kc8adu. Last thing - I don't know what happened to my picture; can one of the mods fix the big gaping hole on my first post so that it is gone? Hehe, it is distracting!

[AKBessy]

Re: FETs soldered or glued on board?

Ok. I ordered new caps for the Micro-Star MS-6312 v.1 board that I have been headaching on and got them all replaced tonight.

I don't know what exactly was going on with the old computer before I got ahold of it. When I got it, the PSU fan would come on, the computer power switch would work, I could hear the hard drive spin. No posting and CD drive door wouldn't open.

I changed out the caps. Put everything back together and am still getting the same symptoms. PSU is supplying power. I unhooked everything and removed the memory, still no beeps. Bad CPU?

[AKBessy]

Re: FETs soldered or glued on board?

Sorry-double posting. Disregard this one and see the one down in the MSI boards. Thanks.

[starfury1]

Re: FETs soldered or glued on board?

Hi

Not sure if its the MB pcb only or a full system in came in you are talking about
Sounds like the box as a whole unit

Sounds like you checked the MB and replaced the caps there
if this was done correctly and solder joints etc are ok
Then there a very good chance it should have fired up

Since it hasn't

OK I'll ask the dumb question.

Have you checked the PSU for bad caps?

have you tried a known working PSU

is other damage possible....yes


if the MB had badcaps and the box has an el-cheapo psu its a fair chance its cactus too.


here's a post by TC on that MB

didn't check version thought
Is it the same as yours ?

How to upload picture as an attachment

Somewhere on the site is a post on how to put up pictures...Think Willawake posted it

It is better for forum readers if you do it as an attachment, so if they do want to look at it they can click to get a bigger image.
(think from memory its how it works...doing a test here to check)

Others will have there own opinion on the above thought

Also you don't want to upload a 4 Meg picture file
(esp if you got say 10 of them) so reduce it file size wise and resize it if need be
(I would only upload a large size if I want people to see the max detail to identify something)

uploads go a load quicker too with say a 200K photo

You do it as an attachment "additional options" Below were you type your replay massage (in advanced)

Attach files (2nd box) click "manage attachments" another box will open with
box and "browse" button, browse to where the pic is on you HDD then click "upload"

NOW WAIT till you see the upload has finished

You should then see it in the "current attachments" in the bottom of the box that opened.
When you "close" that box it should also show your pic file under "Additional options", in the "Attach Files" box

It wont show in the preview post thought. (well it doesn't on my firefox)

Click "submit reply" and it should be there.

you got 10 Minutes to edit you post if you stuff up so be quick

(unless this has changed)

HTH cheers

ok it seems it did it as an attachment only click to view larger

[AKBessy]

Thanks starfury

I am going to move down to the MSI board instead of jumping between two posts. I should have left this one just for that FET question. Anyway, see you down there.