Hello,
Please note I am a noob and all the actions described below are based on the experience gathered on the internet, mainly YT
MSI R9 390 Gaming 8GB - motherboard model MS-V308 v2.3.
The card has a short circuit on the entire + MVDD line, starting from the Q703 element ending with the MVREFD outputs under the GPU, but I will describe from the beginning what I did:
1. At the very start, I measured the resistances on the main power lines, coils and checked the 0 ohm resistors. Everywhere ok, hundreds/thousands of ohms on each, well except the 0 ohm resistors(unfortunately I did not write down the values on the coils ;( ), I remembered 3.5 ohms on the GPU power supply only. Memory power supply - 0.2 ohm. At this point I have abandoned the idea to put the card into the comupter to measure voltage.
2. I started with desoldering Q703 (bottom key?) Because the short appeared to start there. After desoldering, the short circuit remained and the Q703 turned out to be fine. At this stage I didn't have boardview yet so I ran with the meter here and there but found nothing obvious.
3. I have desoldered the L700 choke and connected bench psu to the + side of L700. I set 0.8V on the power supply and turned on the power supply to see what will heat up. At 0.8V, the board consumed more than 5A, the power supply itself was overloaded and I did not notice anything heating up. GPU cold, memory cold, all cold on both sides of the board. For the moment it seemed to me that the U2600 memory module got a little warmer than the rest, but in the end I didn't know if it was due to the short or my fingers warming it. I gradually increased the voltage to 1.2V (yes, I know, a stupid idea when already injecting 5A), I still did not feel anything heating up, but after a while I heard a slight click so I turned off the power supply. As it turned out, the EC200 capacitor fell off and the C2623 capacitor was un-soldered on one side (it was unsoldered from the + MVDD side, not GND).
4. At this point I came to the conclusion that I would desolder each memory module in turn(as they were all shorted), until the short circuit disappears (at this point still 0.2 ohm, and the board, despite falling off 2 elements still took over 5A). After desoldering the last out of 16 modules (U2000), a light appeared in the tunnel, resistance at + MVDD increased to 9.5 ohms measured at L700. Still very low, so I connected the power supply and at 0.8V it was only 0.43A, and at 1.2V 0.53A. There was still nothing hot, and I couldn't find any obviously broken element. At this point I realized that the GPU might have died as the resistance of the capacitors on the GPU was the same as on the L700.
5. I desoldered the GPU, measured the resistance on the L700 and the short was still there, 9.5 ohms. I measured the capacitors on the GPU and the resistances increased to tenths and hundreds of ohms. After connecting the power supply still nothing is noticeably warm. I have decided to search for a boardview (that is how I found this forum btw ).
6. After reviewing the boardview I found out that my short circuit is + MVVD (whatever this abbreviation means). So I plugged in the power supply again, this time I reached for the freezer and frozen everything under the GPU. Unfotunately no obvious results, but a few resistors clearly got warmer faster, even though they were still cold to the touch. These resistors are directly connected to the MVREFD pads under the GPU. I started to desolder each resistor on the MVREFD line one by one and measured the resistances after each. After desoldering the last resistor related to MVREFD, the resistance on L700 increased to 490 ohms, which seems to me to be the correct value. I went through the resistors after desoldering (they had low values on the board), the values looked ok with those from boardview with an accuracy of 1 to 5%. I soldered one of them for a test and the resistance automatically dropped to 110 ohm (the soldered resistor is 100ohms), and each GPU pad connected directly to any of the MVREFD resistor is the same value as the resistors. While back populating the resistors, the resistance got lower and lower till it reached back ~9 ohms.
Sorry for long and boring story but I wanted to illustrate what I did as at this point, I have run out of ideas. Is it possible that the short is in the board itself? Is there anything else I can check? Did I overlook something?
I have also chekcked the GPU pins voltage drop in PCI-E pairs to GND, all have about 0.87V drop so mayby the GPU is not dead yet.
I have attached a pic with the current resistance values.
Can I attach the boardview here as well?
Please note I am a noob and all the actions described below are based on the experience gathered on the internet, mainly YT
MSI R9 390 Gaming 8GB - motherboard model MS-V308 v2.3.
The card has a short circuit on the entire + MVDD line, starting from the Q703 element ending with the MVREFD outputs under the GPU, but I will describe from the beginning what I did:
1. At the very start, I measured the resistances on the main power lines, coils and checked the 0 ohm resistors. Everywhere ok, hundreds/thousands of ohms on each, well except the 0 ohm resistors(unfortunately I did not write down the values on the coils ;( ), I remembered 3.5 ohms on the GPU power supply only. Memory power supply - 0.2 ohm. At this point I have abandoned the idea to put the card into the comupter to measure voltage.
2. I started with desoldering Q703 (bottom key?) Because the short appeared to start there. After desoldering, the short circuit remained and the Q703 turned out to be fine. At this stage I didn't have boardview yet so I ran with the meter here and there but found nothing obvious.
3. I have desoldered the L700 choke and connected bench psu to the + side of L700. I set 0.8V on the power supply and turned on the power supply to see what will heat up. At 0.8V, the board consumed more than 5A, the power supply itself was overloaded and I did not notice anything heating up. GPU cold, memory cold, all cold on both sides of the board. For the moment it seemed to me that the U2600 memory module got a little warmer than the rest, but in the end I didn't know if it was due to the short or my fingers warming it. I gradually increased the voltage to 1.2V (yes, I know, a stupid idea when already injecting 5A), I still did not feel anything heating up, but after a while I heard a slight click so I turned off the power supply. As it turned out, the EC200 capacitor fell off and the C2623 capacitor was un-soldered on one side (it was unsoldered from the + MVDD side, not GND).
4. At this point I came to the conclusion that I would desolder each memory module in turn(as they were all shorted), until the short circuit disappears (at this point still 0.2 ohm, and the board, despite falling off 2 elements still took over 5A). After desoldering the last out of 16 modules (U2000), a light appeared in the tunnel, resistance at + MVDD increased to 9.5 ohms measured at L700. Still very low, so I connected the power supply and at 0.8V it was only 0.43A, and at 1.2V 0.53A. There was still nothing hot, and I couldn't find any obviously broken element. At this point I realized that the GPU might have died as the resistance of the capacitors on the GPU was the same as on the L700.
5. I desoldered the GPU, measured the resistance on the L700 and the short was still there, 9.5 ohms. I measured the capacitors on the GPU and the resistances increased to tenths and hundreds of ohms. After connecting the power supply still nothing is noticeably warm. I have decided to search for a boardview (that is how I found this forum btw
).6. After reviewing the boardview I found out that my short circuit is + MVVD (whatever this abbreviation means). So I plugged in the power supply again, this time I reached for the freezer and frozen everything under the GPU. Unfotunately no obvious results, but a few resistors clearly got warmer faster, even though they were still cold to the touch. These resistors are directly connected to the MVREFD pads under the GPU. I started to desolder each resistor on the MVREFD line one by one and measured the resistances after each. After desoldering the last resistor related to MVREFD, the resistance on L700 increased to 490 ohms, which seems to me to be the correct value. I went through the resistors after desoldering (they had low values on the board), the values looked ok with those from boardview with an accuracy of 1 to 5%. I soldered one of them for a test and the resistance automatically dropped to 110 ohm (the soldered resistor is 100ohms), and each GPU pad connected directly to any of the MVREFD resistor is the same value as the resistors. While back populating the resistors, the resistance got lower and lower till it reached back ~9 ohms.
Sorry for long and boring story but I wanted to illustrate what I did as at this point, I have run out of ideas. Is it possible that the short is in the board itself? Is there anything else I can check? Did I overlook something?
I have also chekcked the GPU pins voltage drop in PCI-E pairs to GND, all have about 0.87V drop so mayby the GPU is not dead yet.
I have attached a pic with the current resistance values.
Can I attach the boardview here as well?
Attached Files
Also, the IRF and the coil is desoldered, may these elements change the value?
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