P51s, HDMI and Power Supply questions

[rebop]

I have a P51S and a 40A2  Ultradock. Without getting into details, there are issues with DP and HDMI connected to the dock.

So here is what I would like to do:

Connect the external monitor to the lap[top HDMI connector and remain docked with Ethernet, USB, etc functional on the dock.

Is this possible?

It appears that docking disconnects the laptop HDMI port. Undocked port works as expected


What would I need to do to achieve this?

Second question: I bought this direct from Lenovo. Dock came with a 90W power supply. This has discrete graphics. Did I get the wrong power supply and perhaps that is at least part of the video out of the dock issues (external screen blalnking at random times - laptop screen never has this issue)?

Thanks.

~Bob

[RealBlackStuff]

There is a 40A2 Firmware.
Try to install/update that on your dock.
90W might work, but try to find a 135W charger for your dock/P51s

[rebop]

Did the firmware some time ago. No change. And still the latest update there.

The P51S came with 65W supply. The cdock with 90W. Never got a 135W. Safe to use? Possible solution for monitor blanking? If so I'll find one

Thanks for the reply!

[RealBlackStuff]

Because of the P-model I thought your laptop had discrete GPU, but if it has integrated GPU, then 90W is enough.
I have a T440p (iGPU) with a 40A2 dock, but I never ever used the dock, so don't know its quirks.
But HDMI cables come in varieties, some with ethernet, some with different HDMI versions, so check what you have.

[rebop]

OH, it DOES have discrete GPU. So I am suprised the low power ratings the adaptors that came with it are. And that I just noticing 7 years later

OK, off to find supply. With luck will solve the problem. Lenovo replied to me that laptop HDMI port is disabled when docked, so that hope of an easy fix evaporated. Hopefully this one will work.

This is the HDMI I have:
https://www.amazon.com/gp/product/B074F ... UTF8&psc=1

Monoprice 4K Certified Premium High Speed Slim HDMI Cable - 4K60Hz, 18Gbps, HDR, 2ft, Black

Thanks again.

[RealBlackStuff]

I'm not familiar with the P-series, but looking up the P51s PSREF, it says it comes with 65W, so 90W should be enough for P51s+dock.
But if you want, check with friends/colleagues if they have a 135W you can borrow.
Also, it looks like P51s is a bit of a souped-up T570, so a larger 'field' to check for problems, if any.
Maybe check the monitor and/or laptop (resolution/frequency) HDMI settings?
It could also be that the HDMI port on either dock or monitor is dirty/loose/faulty.
These docks are around 10 years old by now.

[rebop]

Thanks. Most everything has been checked. I even replaced the laptop fan and monitor CPU and GPU temps (never over 78C) But, as you imply, might be time for a USB C dock as I do believe my issues are at least 50% in the dock. Was hoping for a simple solution.

[RealBlackStuff]

You could also try out another 40A2 dock, they are cheap.
Does your laptop have a USB-C port? (not all P51s have them)
Maybe your monitor is ready for greener pastures?

[rebop]

I have two docks And monitor is newest of all the desk goodies 'cept the Synology NAS. And not only C, but Thunderbolt 3.

[RealBlackStuff]

I'm afraid I'm plumb out of ideas.

[dr_st]

I have a P51S and a 40A2  Ultradock. Without getting into details, there are issues with DP and HDMI connected to the dock.

Why wouldn't you get into details? There should be no issue having dual monitors via DP and HDMI from the dock. You should just connect to the correct DP, since one of them shares a lane with HDMI (and won't work together with it), and the other shares a line with DVI, and can work together with the HDMI port.

[rebop]

This is not dual monitors. Read my details. You are replying to an issue
i do not have.

This is Laptop screen, closed, and external monitor. And not getting into older issues because multiple threads on multiple forums lead nowhere after incredible amounts of back and forth and testing of things. Which is whty I specifically wanted to find a way for the laptop HDMI port to stay live when docked as it never has an issue from that port, or to try something power brick-wise as that is one onf very few things never tried.

[rebop]

Sorry, maybe not clear it happenes with EITHER DP or HDMI from the dock. Perhaps that's why you thought dual monitors.

[dr_st]

Yes, that is perhaps what confused me.

If you have a dock, you cannot get signal from the laptop's HDMI. That was made clear to you by Lenovo support.

I don't understand what issues you have using one of the video outputs on the dock for your external monitor, because you won't explain them for whatever reason. There is no technical reasons why it wouldn't work, unless you have two bad docks, or a bad connection in your laptop's docking connector (which would have to be specific to video outputs, because if I understand you correctly - LAN and USB work through the dock), or a bad monitor (which is unexpected given that HDMI from the laptop works).

Like RBS, I believe 90W should be enough for a dock + laptop, even discrete GPU, but Lenovo's website suggests 135W.

[rebop]

I DID explain. For no reason, it randomly goes black for 1-2 seconds. Once it starts, it happens more often. Might go 6-8 hours no blanking. Then it starts. Or could be 20 minutes after a boot. And does not matter if DP or HDMI. If undocked, and external connected to latop HDMI, will never happen. And is not HDCP, which was a previous issue I did not want to mention and muck up this question

USB C dock likely my best, and most expensive, cure....