Can someone help me find this component so I can get my fan working on this HD 7950

[Rob]

Bottom image is what belongs on the board.








Its labeled AFBV 1A. I can't find any data anywhere on this.

Thanks all!

[chozo4]

Re: Can someone help me find this component so I can get my fan working on this HD 79

What is not causing the fan to work to begin with? Is it a bad component, bad fan, or just a different hookup? Cannot find the AFVB 1a on the pictures due to being blurry. The alternative would just as well be to wire the fan to a separate power source from the PSU if it's just not getting power at all. If it's working but not being controlled via voltage or PWM then that's a different story.

edit: OH! I see now after closer inspection as it was very hard to see the thin dark blue circle in there.. that's actually a surface mount transistor to help get you started. Seems to be more related to the PWM circuitry I would assume. I'm blindly assuming it's a NPN tranistor and from a quick look this looks something close to what you need. It hands up to 0.6A but most fans, even for a GPU won't even go that far if it's being used to handle fan duty.

umt2222a/SST2222A


Just for future reference... components marked with a Q (Q12 for example) at the start indicate tranistors. However, before you start adding components though, what is actually wrong with the fan functionally?

[Rob]

Re: Can someone help me find this component so I can get my fan working on this HD 79

Fan works fine, the card will not run the fan off the header. I want to replace that transistor so I can run it through the actual card.


Thanks for the advice, I was super lost for a while.

[chozo4]

Re: Can someone help me find this component so I can get my fan working on this HD 79

hmm, if at worst you could make sure there are no traces running from the + of the header to anything (as in not connected to anything). Then after you can just use a multimeter to find where the voltage for 12v,5v, whatnot is coming in and run a jumper wire from there on the card to the header. Then after you can use the header accordingly. Just double check where each of the 2 traces go to be sure.

[Rob]

Re: Can someone help me find this component so I can get my fan working on this HD 79

I ordered an SST2222A transistor and will solder it on once it arrives. Unless I completely hack the solder job I hope this does the trick.

[budm]

Re: Can someone help me find this component so I can get my fan working on this HD 79

Before removing that transistor, you should check the voltage on the Emitter and the Base using both DC mode and AC mode on the meter to see if it is getting the drive signal or not.

[chozo4]

Re: Can someone help me find this component so I can get my fan working on this HD 79

Before removing that transistor, you should check the voltage on the Emitter and the Base using both DC mode and AC mode on the meter to see if it is getting the drive signal or not.

Their issue is that it's missing the transistor and only an empty pad rather than removing an existing one. I assume it's probably originally made for a passive sink than to run a fan otherwise hence the lack of a header and transistor to drive it.

[stj]

Re: Can someone help me find this component so I can get my fan working on this HD 79

then it's probably also missing the base drive resistor and maybe other stuff too.

[Rob]

Re: Can someone help me find this component so I can get my fan working on this HD 79

The rest of the components are in tact. This was knocked off by someone who was a little rough at uninstallation. I located almost every single component on the board, everything else is definitely still there.

[momaka]

Re: Can someone help me find this component so I can get my fan working on this HD 79

Its labeled AFBV 1A.

Could be a 2N3904, then - a standard NPN transistor good for 200 mA and 350 mW. It's SOT-32 version is MMBT3904, but it's marked as "1A".

The 2222 you got would likely work fine too, though. In the SOT-23 world, it is known as "1P" and possibly other part numbers as well.

[chozo4]

Re: Can someone help me find this component so I can get my fan working on this HD 79

Good to know then momaka. I have little to no experience with a majority of surface-mount parts so was generally a shot in the dark with a general idea. Good to know I was at least spot on for the most part.

[Rob]

Re: Can someone help me find this component so I can get my fan working on this HD 79

I also ordered MMBT3904 since it was in the states. These will come in faster. They are cheap enough where I won't be upset that I have 100 pcs of a transistor I will never use.

[jetadm123]

Re: Can someone help me find this component so I can get my fan working on this HD 79

I know it's a little late, but Radio Shack does sell the 2N3904 and 2N2222 transistors. They are not surface mount, but regular transistors with leads. However, you can bend the leads to fit the pads on the board. Saves a lot of waiting time and you don't have to buy a 100.

[Rob]

Re: Can someone help me find this component so I can get my fan working on this HD 79

I wish I knew that sooner. It's ok though because I had to order new thermal pads for the ram and VRMs anyways. The old ones were degraded.

[Rob]

Re: Can someone help me find this component so I can get my fan working on this HD 79

Would I have been able to leave the leads longer and then hot glue it flat to the PCB? It would probably be easier to solder. How do I know which lead goes where on the PCB?

[jetadm123]

Re: Can someone help me find this component so I can get my fan working on this HD 79

Download the datasheet for the surface mount version, then compare the leads to the ones on the package of the new transistor. Always pre-bend/cut the leads prior to soldering.

[budm]

Re: Can someone help me find this component so I can get my fan working on this HD 79

Example of how I do it:
http://s807.photobucket.com/user/bud...ml?sort=3&o=27
http://s807.photobucket.com/user/bud...ml?sort=3&o=26

[Rob]

Re: Can someone help me find this component so I can get my fan working on this HD 79

Found one:

Looks like the collector isn't in the center on the regular transistors like they are on the surface mount. I will have to either have it stand straight up or lay it sideways to make it work. I may just wait for the surface mount transistors to arrive but it still maybe easier to solder the regular one on due to the longer leads.

[momaka]

Re: Can someone help me find this component so I can get my fan working on this HD 79

I also ordered MMBT3904 since it was in the states. These will come in faster. They are cheap enough where I won't be upset that I have 100 pcs of a transistor I will never use.

That's why we highly suggest to put at least the state and country in your profile.
I have plenty of dead hardware that has these transistors and could have pulled a few and mailed them to you in a regular mail envelope.

I may just wait for the surface mount transistors to arrive but it still maybe easier to solder the regular one on due to the longer leads.

Surface mount is easier to solder if you have the right part.
Leaded components can work on SMD, but you have to be careful and pre-bend the leads before soldering anything, as jetadm123 noted. Otherwise, you could damage the SMD pads if you accidentally bump the transistor or try to move it around with the leads soldered.

[chozo4]

Re: Can someone help me find this component so I can get my fan working on this HD 79

That's why we highly suggest to put at least the state and country in your profile.
I have plenty of dead hardware that has these transistors and could have pulled a few and mailed them to you in a regular mail envelope.

I think it's fair to say we all have something chock full of transistors to spare. Salvaged broken up boards from a destroyed projection TV with more transistors than I will possible ever need for a lifetime.