No signal Dell Precision T1650

Maybe I missed something but it seems like you have followed all the steps for diagnosis except try another monitor. Maybe too obvious but it looks like the only thing left.

Thank you for your reply, but apparently the monitor is fine, cause I managed to run the system once, and everything was working without any glitches. It led me to conclusion, that monitor is not an issue.

PS. By the way, I tried second monitor (TV, to be exact) at the same time, switched cables between them, connected to different ports at videocard, and the only time it worked was with the original monitor.

But thanks anyway. I must be cursed or something :Smile:

Just a random though, so I am probably wrong.

Have you tried harder changing BIOS to default settings?  I have carefully read your post, but it is not clear to me if you have plugged in AC power to the system after changing the jumpers to clear CMOS.  It is a required step.  You removed the CMOS coin cell battery, I know, but have you drained all residual power from the system before putting the coin cell battery on the mainboard again?

I am suggesting trying harder these steps as some BIOS settings may be the source of a behaviour like the one you are seeing.  It happened to me some time ago; in that case the machine had no obvious failures, no beep error codes and power button LED was white, so no errors found by POST, but it was booting only one of five times, showing a blank screen in other cases (just a blank screen, as there was a signal coming from both DP ports, slightly different to your case).  That failure was caused by the Intel Trusted Execution Technology (TXT) enabled but not being provisioned in the right way —my fault, as enabling TXT locks NVRAM— before adding some hardware (a 16 GB RAM module and a 4 TB HDD, both original Dell parts for that workstation.)

You may have another chance to reset NVRAM by pressing Ctrl+ESC while booting until BIOS recovery menu appears.  Right now I am not convinced you have a hardware issue, but it is hard to say without looking into your workstation.

Edit: the best choice would be going into BIOS setup, if you have a chance to turn on again your workstation, and return it to factory settings so you can discard some sort of assurance technology as the source of the behaviour your machine suffers.  If you are able to turn the workstation on again, then I would run diagnostics on it too.

Actually, I plugged AC power after switching jumpers, and run it for 30 secods (that is enough, as far as I know). The same applies to removing CMOS battery. I didn't know, what exactly I had to do to drain all residual power, so I connected AC power, and sometimes even hold power button for an entire process of system's download.

My biggest concern is inability to wake up screen by holding any keys on my keyboard (Ctrl+Esc, F2, F8, F10, Del, doesn't matter), so I can't reach any BIOS settings manually.

Going to try all these steps again today, thank you for your reply!

Two additional tips:

1. Remove anything not required to boot the workstation (i.e., start with just the PSU, motherboard, monitor, a single memory module and a USB keyboard); if it boots add additional hardware (HDD/SSD, ODD, cards...) until you find the problem.
2. Test the PSU; I understand your workstation has a test button on the PSU.  Use it.

Hope this helps.

It seems CMOS has been reset in the right way.

If the machine is working you can install another graphics card on it.  I understand BIOS video setting is "auto," so your workstation should be bootable and you should be able to use it with your monitor again.  From here you should be able to reset BIOS settings (a security setting like Intel TXT will probably need a manual disable from the BIOS menu, just returning to factory settings may not affect TXT status), run the hardware diagnostics or even identify the on-board graphics as the responsible of this failure.

For testing it does not need to be a high end graphics card.  I would avoid a high end ATI/AMD or NVIDIA card as the power supply on your small workstation may not be enough to power it.

This PC has an internal graphic card, wouldn't it be suitable? I tried to connect monitor cable to it, but with close to no success.

 

Whith regard to testing PCU, I used a multimeter to check whether every module has a power supply, and it definitely has. So I don't blame PCU here, if I understand the proccess correctly.

I fear I had been no clear enough.

• No, the internal graphics card may not be suitable .  It can be dead, as any other component on your workstation.  Sometimes only a part of the motherboard is damaged (the internal graphics card or some or all of its video ports may be broken in your computer), so it is better trying another one as part of the troubleshooting process.
• I would suggest using the built-in self test (BIST) feature of the workstation PSU.  This video from TechSupportDell may help you understanding the process.  Any component may be failing.  It is better starting with as few hardware as possible (e.g., motherboard, one memory module, a monitor and an USB keyboard) and, in case it works, adding more hardware and try to turn on the computer again.  At some point you will either find the device that renders the workstation unbootable or discover that the problem was a bad connection of one of the devices.