VOGONS

EVGA GTX 970 SC GAMING ACX 2.0 - Broken [Repaired]

Topic actions

First post, by zuldan

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie

Thought I'd share my experience with this EVGA GTX 970 I bought for "Parts / Repair" as the 9xx series make great ultra fast Windows XP cards for retro builds. Buying EVGA cards is always a risk as there are now boardview / schematic files for these cards (and the Asus/Gigabyte/ MSI PCB's look very different).

The attachment Front.jpg is no longer available

After doing the usual voltage measuring at keys points I found there was no VRAM voltage (and so PEX as well). Everything else on the card is looking good including all phases with an oscilloscope. The resistance on the memory coils is good, 20 ohms, which is normal for Samsung.

The attachment Memory 0v.png is no longer available

I came across this article which gave me a hint as where to diagnose the problem https://www.eevblog.com/forum/repair/msi-gtx970-4g-oc/

RAM voltage is generated from this area on the rear of the board. The "08 1G V17" IC is this one https://www.richtek.com/assets/product_file/R … DS8809AB-02.pdf

pin 2 VREF is 2v
pin 1 VSET is 1.5v
pin 17 VDD is 4.8v
pin 12 VCC is getting 12v
pin 3 EN is 0.34mv Hmmmm

The attachment 20240615_224019.JPG is no longer available

Since I don't have the schematics I couldn't check nearby resistor values so I decided to replace the RT chip. I ordered new ones from https://www.aliexpress.com/item/1005009324849779.html

To my surprise, the Aliexpress chip worked. The VRAM voltage came back online and now the card works perfectly!

The attachment 970 GTX.png is no longer available
The attachment s-l1600.webp is no longer available

Reply 1 of 3, by Barley

Posted on 
User metadata
Rank Newbie
Rank
Newbie

Very impressive! How did you learn how to diagnose issues like this, and make the repairs?

I need to do the same thing on a non-working Dell 2007FPb monitor.

Reply 2 of 3, by zuldan

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie
Barley wrote on Yesterday, 22:50:

Very impressive! How did you learn how to diagnose issues like this, and make the repairs?

I need to do the same thing on a non-working Dell 2007FPb monitor.

I'm actually a noob trying to learn all this stuff, just ask @tehsiggi 😉

Watched a ton of northwestrepair https://www.youtube.com/@northwestrepair) and TechCemetery (https://www.youtube.com/@TechCemetery) videos. I've also had previous soldering experience with a previous hobby.

Those Dell 2007FPb monitors are awesome. I actually found one at a garage sale for $1 last week (Re: Bought these (retro) hardware today). Might be easier purchasing another (working) 2007FPb (you can get them for pretty cheap) and then compare the 2 to diagnose the issue. Hopefully it just needs new caps.

Reply 3 of 3, by tehsiggi

Posted on 
User metadata
Rank Member
Rank
Member

Good work, sometimes its good just to follow intuition. And if you have parts available, swapping out things to see it changes behavior is a quick way of ruling out things.

We live in a time, where everyone can share their experiences (and opinions, for what it's worth 😁) so learning things like this has become easier than ever. That is the reason why sharing such repairs, apart from the usual tech youtubers, is important. Other people can read through it, follow it, gain knowledge and hopefully repair their own stuff.

I am personally more a fan of written reports like this one, because search indexing works just better than with videos.

Again, nice work!

AGP Card Real Power Consumption
AGP Power monitor - diagnostic hardware tool
Graphics card repair collection

Go to top of page Go to top of page
Back to Video
Close window
Close window