AX3650 no display

[boyrekta]

Hi Guys,

I'm new here, just got tired of searching answers using Google so decided to look for forums that could hopefully resolve this video card problem.

I have an AX3650 that has no display but has power. I had those bloated caps that I've replaced ( 3 pcs 6.3v 1000uF ) but still no luck.

I've used the oven technique and still no avail.

I noticed that one of the r60 inductors ( shown in picture right side ) heats up but the GPU does not.

Another thing is when I connect the DVi cable from the monitor it does not detect any signal, from what I know even if the computer/vga is off the monitor should detect it and just go on standby.

I wonder why does the inductor r60 heats up or could this be causing it? I've already removed these inductors to be tested and they have the same value 5 ohms.

Any help would be greatly appreciated.

[momaka]

Re: AX3650 no display

Those gray boxes in your picture are inductors. The "R60" on top means the inductance is likely 0.6 uH. The one that heats up appears to be for the RAM buck controller (i.e. RAM VRM).

When you power the video card, do the black RAM chips get very hot very quickly as well? (Be careful! Shorted RAM can get very hot in a few seconds and could even burn your fingers.) If yes, you might have shorted RAM - likely a result of the bad caps. But I wait for you to confirm.

[boyrekta]

Re: AX3650 no display

Those gray boxes in your picture are inductors. The "R60" on top means the inductance is likely 0.6 uH. The one that heats up appears to be for the RAM buck controller (i.e. RAM VRM).

When you power the video card, do the black RAM chips get very hot very quickly as well? (Be careful! Shorted RAM can get very hot in a few seconds and could even burn your fingers.) If yes, you might have shorted RAM - likely a result of the bad caps. But I wait for you to confirm.

thanks for the reply,

the only thing that heats up is that r60 inductor the one on the picture. It's also weird when plugging this to the monitor, it does not detect signal from it. Already tried other monitors but no signal being detected from this card.

I'm tracing the terminals of the inductor's pin but I'm really having a hard time locating the next component that might be causing the problem. getting dizzy

I hope you can help me with this since your the only one who seems to bother looking at my post. I'm grateful

[stj]

Re: AX3650 no display

see if the 2 devices to the right of it are shorted - they are probably fets - but your foto is a bit lo-res

[boyrekta]

Re: AX3650 no display

see if the 2 devices to the right of it are shorted - they are probably fets - but your foto is a bit lo-res

hmmm you know I was actually thinking of those 2 fets, problem is I have no hot air to remove them, maybe I can remove their pins and put a replacement above them if they are faulty? What do you think?

[stj]

Re: AX3650 no display

i think you can probably check for shortswithout removing them.

[boyrekta]

Re: AX3650 no display

i think you can probably check for shortswithout removing them.

hey bro, both fets are shorted i'll try to replace them by removing their pins and putting a new ones top. i'll give you an update. Thanks.

[momaka]

Re: AX3650 no display

see if the 2 devices to the right of it are shorted - they are probably fets - but your foto is a bit lo-res

I would be surprised if both are shorted. Either upper or lower is shorted.
If lower is shorted, the result is usually PSU overload (PSU detects short circuit and turns OFF/latches). Rare cases that the computer will continue to stay turned ON. If it does, then that coil will never get hot as the lower MOSFET will be providing the path to ground from the upper MOSFET.
If upper MOSFET is shorted, the result is, again, usually PSU turns OFF due to short circuit protection. If it didn't, the GPU or RAM (whichever is using that rail) will burn out and get very very VERY hot.

If better pictures are provided, I can help find out which MOSFET is shorted (if at all).

hmmm you know I was actually thinking of those 2 fets, problem is I have no hot air to remove them

You don't need hot air to remove them. Just two soldering irons, lots of solder and lots of flux. One of the irons preferrably should be rated for 50W or more and with a chisel tip. If both are 60W, this will be easily doable.

The way you do is first you add a bit of solder on the tab of the MOSFET. Next, add lots of solder to cover all of the pins of the MOSFET on the other side. Finally, take both irons (both should be heated up for at least 5 minutes), put one on the MOSFET's tab, and the other on the solder blob that covers the pins. When the solder melts, slide the MOSFET away in a clear area on the board. Be careful not to pick up and move any small resistors as you do this. Looking at the pictures you provided, there is plenty of space to easily slide the MOSFET off the board and not disturb anything.

i think you can probably check for shortswithout removing them.

[boyrekta]

Re: AX3650 no display

I would be surprised if both are shorted. Either upper or lower is shorted.
If lower is shorted, the result is usually PSU overload (PSU detects short circuit and turns OFF/latches). Rare cases that the computer will continue to stay turned ON. If it does, then that coil will never get hot as the lower MOSFET will be providing the path to ground from the upper MOSFET.
If upper MOSFET is shorted, the result is, again, usually PSU turns OFF due to short circuit protection. If it didn't, the GPU or RAM (whichever is using that rail) will burn out and get very very VERY hot.

If better pictures are provided, I can help find out which MOSFET is shorted (if at all).


You don't need hot air to remove them. Just two soldering irons, lots of solder and lots of flux. One of the irons preferrably should be rated for 50W or more and with a chisel tip. If both are 60W, this will be easily doable.

The way you do is first you add a bit of solder on the tab of the MOSFET. Next, add lots of solder to cover all of the pins of the MOSFET on the other side. Finally, take both irons (both should be heated up for at least 5 minutes), put one on the MOSFET's tab, and the other on the solder blob that covers the pins. When the solder melts, slide the MOSFET away in a clear area on the board. Be careful not to pick up and move any small resistors as you do this. Looking at the pictures you provided, there is plenty of space to easily slide the MOSFET off the board and not disturb anything.

wow! thanks for these answers, yeah I watched a video in youtube how to remove a mosfet using a soldering iron, I used a 120W and whew it popped up right away ( well the other one got fried ), Ive replaced them both though but I haven't tried it yet since it's was late and now I'm at work.

I'll get a clear picture of it and post it later as soon as I arrive home. Although that is kind of messy since I'm a noob on soldering mosfets. I really want to fix this for my pocket's sake and especially for knowledge. Thanks guys

[boyrekta]

Re: AX3650 no display

[boyrekta]

Re: AX3650 no display

well guys replacing the mosfets didn't help, still no display and the inductor on the right still heats up.

i hope this picture helps

[momaka]

Re: AX3650 no display

The electrolytic capacitor is missing next to those MOSFETs. Please tell me you had one before testing this. Otherwise, you may have cooked the RAM or GPU (or whatever is powered by that rail).

Since there isn't much to loose now, might as well replace the inductor and see what happens. You'll need a 0.6uH inductor, though I would venture and guess that anything up to 1.2 uH might work too. 1.2 uH is a standard value for older motherboard inductors around the CPU VRM.

So look for something in the range of R60 to 1R2 (i.e. R60, R70, R80... 1R0, 1R1, 1R2).

Your replacement capacitors are also likely no good. They appear generics so are likely general purpose. You want low ESR caps. Something like Chemicon KZE, Rubycon ZL, Panasonic FR, and Nichicon HD would be the minimum. Preferably, go with Nichocon HM/HN or Rubycon MBZ/MCZ.

[boyrekta]

Re: AX3650 no display

The electrolytic capacitor is missing next to those MOSFETs. Please tell me you had one before testing this. Otherwise, you may have cooked the RAM or GPU (or whatever is powered by that rail).

Since there isn't much to loose now, might as well replace the inductor and see what happens. You'll need a 0.6uH inductor, though I would venture and guess that anything up to 1.2 uH might work too. 1.2 uH is a standard value for older motherboard inductors around the CPU VRM.

So look for something in the range of R60 to 1R2 (i.e. R60, R70, R80... 1R0, 1R1, 1R2).

Your replacement capacitors are also likely no good. They appear generics so are likely general purpose. You want low ESR caps. Something like Chemicon KZE, Rubycon ZL, Panasonic FR, and Nichicon HD would be the minimum. Preferably, go with Nichocon HM/HN or Rubycon MBZ/MCZ.

thanks for the advice, I'll get a replacement for the inductor with 1.2uH. about the caps, I'll try to look for a better brand, here in the Philippines we have few electronic stores that sells these electronic components so we only get what they have. About the cap near the mosfets, I soldered it on the other side

I'll post an update afterwards maybe next week . Thanks again!

[Hemingray]

Re: AX3650 no display

About the cap near the mosfets, I soldered it on the other side !

Make sure you didn't solder it in backwards.

[boyrekta]

Re: AX3650 no display

well guys i think this is the end for my card, I went to every store I know but non of them supplies r60 inductors. I guess it's time to have it replaced. Thanks to all that replied on this thread, I really appreciated them.

[momaka]

Re: AX3650 no display

You don't need exactly R60 inductors. Could have done it with others, as stated above. Best bet is other junk video cards or motherboards.

But I guess you made you decision.
In that case, you can put it up on eBay for parts/repair for cheap. You might get a few $$ back (but don't expect much).

[boyrekta]

Re: AX3650 no display

You don't need exactly R60 inductors. Could have done it with others, as stated above. Best bet is other junk video cards or motherboards.

But I guess you made you decision.
In that case, you can put it up on eBay for parts/repair for cheap. You might get a few $$ back (but don't expect much).

Unfortunately the video cards I have in here are AGPs they have the small ring that has a wire swirled on it that looks thin so I guess it wont work. Don't have motherboards on stock as well. But if ever I get one I'll try it definitely

Thanks for the advice on selling it but i think I'll just keep it. Somehow it acquired a sentimental value