11-20-2019, 07:51 AM
> Although it seems I have a lucky board.
In the case of a lucky board, there is no way to check the effect.
In my case, the symptoms appeared at the "boot" stage, so it was easy to check the effect.
unit 1: 10/10 @ x4 / Gen2
unit 2: 10/10 @ x2 / Gen2
unit 3: 3/10 @ x4 / Gen2, x4 / Gen1, x2 / Gen2, or Crash.
---
The component of interest is near the "PCI-Express" connector.
The parts are very small,
You must assume that the removed parts cannot be restored.
I haven't confirmed it by spice simulation,
I think "C50007 / C50008" has little or no effect.
In fact, I have left these two parts as they are.
(The inserted capacitance for the GHz signal is 100nF. Even if 100nF is changing to 50nF, it is within the margin of error)
I first tried from the "R89506 / R89507" short (0Ω), which can be expected to be effective without removing the parts.
This change alone was sufficient to confirm the effect. (unit 2: 10/10 @ x4 / Gen2)
I was able to confirm the effect as expected, and then I removed all the remaining resistances、I did the same for all units.
In the case of a lucky board, there is no way to check the effect.
In my case, the symptoms appeared at the "boot" stage, so it was easy to check the effect.
unit 1: 10/10 @ x4 / Gen2
unit 2: 10/10 @ x2 / Gen2
unit 3: 3/10 @ x4 / Gen2, x4 / Gen1, x2 / Gen2, or Crash.
---
The component of interest is near the "PCI-Express" connector.
The parts are very small,
You must assume that the removed parts cannot be restored.
I haven't confirmed it by spice simulation,
I think "C50007 / C50008" has little or no effect.
In fact, I have left these two parts as they are.
(The inserted capacitance for the GHz signal is 100nF. Even if 100nF is changing to 50nF, it is within the margin of error)
I first tried from the "R89506 / R89507" short (0Ω), which can be expected to be effective without removing the parts.
This change alone was sufficient to confirm the effect. (unit 2: 10/10 @ x4 / Gen2)
I was able to confirm the effect as expected, and then I removed all the remaining resistances、I did the same for all units.