T480 - black screen when powered on

[br1anstorm]

I have just taken delivery of a refurbished T480. When I press the power on button, it lights (as does a little light in the Esc key), but the screen remains totally black. Not even a blinking cursor.

Further (longer) presses on the power button sometimes result in its light blinking slowly on and off - which I thought meant it was hibernating.

After a very long press on the button, it turned off. And when I pressed again to turn it on, there was a peculiar and unfamiliar musical sequence of beeps. I had never heard that on any of my other Thinkpads (and it isn't the tune played by Windows on boot-up).

A quick browse and search suggests that the musical sequence signals a problem, possibly with the RAM.

I've contacted the seller and organised the return and exchange of this laptop for a like-for-like replacement. But I'm wondering if, while I wait for that , there is anything else I can do to diagnose, check and troubleshoot.

My instinct would be, at the very least, to open the back and remove/reseat the RAM modules. Before opening up, it's necessary to remove the external battery and also disable the internal one. Normally this latter step is done in the BIOS. But since I can't even get a BIOS screen, that's not an option.

I don't want to do any damage inadvertently. Would it be OK to remove the external battery, remove the back cover and then manually/physically unplug the connection to the internal battery before I remove and reseat the RAMs?

[axur-delmeria]

I haven't tried this, but apparently Lenovo has an Android app that can decode those error tones:

https://play.google.com/store/apps/deta ... s&hl=en-US

[br1anstorm]

Thanks @axur-delmeria .... I had seen a mention of this somewhere else, but wasn't clear if it was still available.

Sadly, having just checked, it seems that the app is only available on phones running Android 13 or newer.

Just as I continue to rely on old(er) Thinkpads, my phone is also not the latest model - it runs Android 10.

So I fear I can't make use of the app to decode the laptop beeps.

I guess that leaves me with more old-fashioned options for trying to diagnose the black-screen problem.

Which brings me back to the original question: can I/should I disconnect the internal battery manually before checking the RAM, and will this avoid any other damage?
I've seen mention that failing to disable that internal battery properly can blow the backlight.

[RealBlackStuff]

Yes, you can physically disconnect the internal battery before you do anything else.
Do you very vaguely see anything at all on the LCD, when you look at it from a 45 degree angle?
Have you tried an external monitor?

[br1anstorm]

Thanks, RBS, for that reassurance about disconnecting the internal battery.

To answer your other questions, No and No.

Looking at the screen from any angle reveals no glimmer of any kind of image.

I haven't (yet) tried an external monitor as the only one I have is an ancient Dell item which is buried somewhere in a box in the garage... if I have time over the weekend I might try to dig it out. But I fear a T480 might not have the right port for its rather ancient connecting cable/plug.

[br1anstorm]

A quick update.... mainly to say that my earlier reply to @axur-delmeria was perhaps misleading.

I went looking for the Lenovo Diagnostics "Smartbeep" app, and found that it would install on my mobile phone. So I figured it was worth a try.

I powered up the faulty T480, and sure enough, black screen and a curious series of melodic beeps, which I was able to capture on the app. [Tip: if necessary, you can get the laptop to replay the beeps simply by pressing the Fn button].

After a few moments the app displayed a fault code and diagnosis on my phone screen. The code is 0288, and the verdict is "Computer Display Error", for which the recommended action is
"1. Reconnect the display cable on both the system board side and the computer display side (service provider only).
2. Replace the system board (service provider only)."

My guess is that it may just be a bad connection. Perhaps the cable or screen has been bumped or disturbed during shipment. So @RealBlackStuff was right to suggest I might try an external monitor. Unfortunately I don't have a monitor with suitable connections. But anyway, this refurbished T480 was supplied with a warranty and return/refund/replace guarantee. So I'm not going to start messing with the screen. I'm just going to return the laptop and request a replacement.

Thanks for the comments and advice. I hope the replacement, when it arrives, will be 100% good.