PC Graphics

[vegafan]

Hello,

My Reference Vega 64 has had its U100 chip ripped off the board.  I'm looking to replace the chip and have it soldered back on.  I'm struggling to find any information what this chip might of been as its far too small to show up clearly in any pictures online.  Any help would be great, i've attached a photo of the chip to the post.

Thanks

[grimbloodwolf]

It's a resistor, without more information though it's extremely difficult to tell the value...... U100 resistors can be anywhere from 100 Ohms up to 100 kOhms.... do you have a multi meter? If the component didn't get damaged when it got ripped off, you could try to find out what its resistance value is...... it wouldn't be too tough to solder the component back on, but you're going to need some magnification and a decent drop of flux.

[vegafan]

Sorry I think my picture is a little misleading.

Im referring to the IC beneath that resistor. It appears to be a 5 pin SOT 353 package.

[grimbloodwolf]

Yeah.... it's very hard to tell what the little component is from the image, and I've not been able to find much better images really, does the package have anything other than u100 etched on it?
Just out of curiosity, how'd it get knocked off?

[vegafan]

I’m not sure why it came off actually.

I had to of done something wrong when i took the reference cooler off.

U100 is the only label I can see. The chip appears to be gone so idk what etching it may of had.

[grimbloodwolf]

Might have found a thread over at eevblog that might be helpful to you.... it appears that little package appears on Radeon cards going back a long way, this guy knocked the same package off his card and was able to fix it using a donor from an older Radeon card.
[UPDATE] [SOLVED] Need help identifying this chip (on a Radeon HD Graphics Card) - Page 1

[elstaci]

according to Wikipedia Reference designator for electronic components in PCBs the "U" stands for integrated Circuit: Reference designator - Wikipedia

Your best bet is to find another broken or bad Vega64 and cannibalize the part from that card to repair yours. colesdav​ is an excellent Technician who has physically repaired several of his GPU cards and may be able to give you some pointers on how to repair correctly.

Sometimes the same electronic components are used in several AMD GPUs. So it is a good idea to check other AMD GPU broken cards and see if they have an IC labeled U100.

[colesdav]

Hi,

I could not see from the image what the component is exactly.

Your first step is to contact PowerColor/Sapphire/MSI/XFX/ whoever manufactured the GPU.
Open a support case with them.
They may be able to help you identify exactly what the component is.
PowerColor Support do have a parts database that they can check.
RMA the GPU if you can, but since it has been opened they may refuse to accept the GPU for RMA depending on your location.

I just bought a new XFX RX Vega 64 Liquid before Christmas but it has a 2 year Warranty and there is no way I am opening it as it will void the Warranty.
If I decide to purchase a 2nd hand Vega 64 this year I will take a look at the component.
Sorry I cannot help you out more.
  

It will be very difficult to refit that component manually using a standard solder gun, especially if the PCB solder pads are damaged.
You can get some good low cost tools for manual surface mount work, but it is much better to use professional equipment.

Your best bet is to see if there is a local University or Technical College near you which has some proper surface mount equipment and someone may attempt repair for you using proper equipment if you can identify, test the original IC is OK or source the replacement IC from somewhere.

Bye.

[ixkawa]

i know this is old but this reply is for anyone searching this in the future .. actually turned out that you can short-circuit R104 resistor pads (you won't find it written on the board) just below this U100 chip since its a non inverting buffer you can bypass it by simply doing that .. input and output are pins 2 and 4 which are directly connected to the resistor pads just below it.

somebody did manage to get his card (an HD4850) working by doing this, yeah not the same model but this board design is very very common and same as what you mentioned.

i had the same problem with this R9 of my friend .. he knocked off the same ic (U100) some how and this what i am planning to do, HOPE IT WORKS !!

[ixkawa]

turned out to be false .. the ic chip i inspected "U100" appears to be an AND logic gate in various radeon HD/R/RX boardviews .. different ic names but all of them are 5 leg 2 input 1 out put AND gate .. input pins 1&2 ground is 3 output is 4 and 5 is +3.3v .. the output appears to be connected to the VRMs Mosfets gates .. at least i learned a lot about gpus repair while searching this !