That's a long story, and I ended up here, cause I have no idea what to do anymore.
Everything works fine, CPU is fine, RAM is fine, Video card is fine, all coolers are fine, all LEDs indicate that system is completely fine, but monitor still shows annoying "No signal" message. And yes, I've read all related topics before questioning.
It started long ago, around 3 years ago. System went black, no signal, nothing helps, okay. Somehow I managed to remove CMOS battery, insert it back, and voila - everything is working. Couple of weeks later the issue repeated. Same procedure, and everything is fine. Next call was even closer - one week later. Then two days, one day, and then it happened - it went permanent "No signal", same battery didn't work, new battery didn't work, and I forgot about my PC for a year. Sometimes I tried to revive it, but with the same result. Even bought a new Display Port to HDMI cord (from PC to monitor). Half a year ago I decided to put an end to this problem, and run a diagnostic myself. Removed all RAM, counted beeps, got 1-3-2, and somehow messed up with the guide, and decided that the problem was with the CMOS battery. Another battery, same result. Cleaned the battery, cleaned contact square, same result. Ordered new motherboard from ebay two months ago - I just couldn't find a motherboard so old in the whole country. And here it is - my brand new motherboard arrived. Gently disconnected all the cables, removed CPU, removed thermal grease, put a new one, assembled it all together. No signal. Messing with the RAMs, I managed to get a power button LED code error (2,3), which indicates that something is wrong with the RAM. Following the instructions, I removed all the RAMs (got a fair 3,3 error - "RAM is missing"), put it consequently in 3 slot (power LED is stable white), 1 slot (still white), 4 slot (still white) and finally 2 slot, and it began to flash amber (2,3) again. Then I simply swapped 4th and 2nd slots and it became stable white. Still No signal though. After a thousand of attempts system suddenly worked, and I've seen a starting screen, log on to Windows, and even used my PC for an hour, which excludes broken monitor, broken cords, broken anything versions, but the irony was that I acheved this result with only one RAM installed in 4th slot. I had to reboot at least to install other RAMs. Of course I reloaded the system with the same condition (1 RAM exactly in the same place), and surprisingly it went the same "No signal" condition again. I spent the whole day-off trying to revive it, and it still doesn't work. Now it's working completely well, steady white power LED, no beeps, coolers are buzzing, but the signal is missing.
Reload - done
Removing CMOS battery (and 30-secs without it and everything) - done a numerous times
Changing CMOS battery - done twice
Changing monitor cord - done
Changing motherboard - done
Changing position of PSWD-RSTC key - done
Take in and out RAMs - done
Cleaning CMOS square - done
Cleaning RAM - done
Check power on every single device inside the computer - done
Actually, I've given up, and already decided to buy a new pack of RAMs, cause it's a nightmare, really, but I'm not even sure it will help.
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(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!
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.
Two additional tips:
Hope this helps.
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.