No signal detected

Rhadan · 09-17-2006, 08:10 AM

Hi all!

I have a big problem.

I just purchased a new computer, and tried to set it up over the weekend.

The fun thing is, when I turn it on, my BenQ monitor (FP937s) doesn't get a signal. My graphic card (GForce 9600GT) only has 2 DVI outputs - and I tried plugging in the DVI cable. As that one didn't work, I plugged an adapter to the DVI output and tried connecting via D-Sub. Nothing.

Now I thought that the graphic card might be the problem, and (with a sigh), tried to plug in my old computer - with the SAME results (although it worked fine a couple of hours ago).

NOW my thought was that it might be the monitor who has a malfunction, and tried an old 17" monitor (non-TFT).

And - it doesn't work either!

I'm pretty much out of ideas ... nothing seems to work, whenever I turn on my TFT I just get "No signal detected".

I don't know what to do anymore.

Does anyone have any ideas?

Will.Spencer · 09-17-2006, 08:52 AM

Let's see, what are all possible causes of a "no signal" condition:

1. PC is not turned on

2. Bad video card
3. Bad monitor
4. Bad video cable
5. Loose video cable
6. Incompatible video card and monitor

You might have a mix of these issues. Something like "the new monitor is bad, and the old monitor is incompatible with the new video card."

As the system is new, I would take it back to the place where you purchased it. That's probably much easier than troubleshooting it.

Rhadan · 09-17-2006, 09:05 AM

Hi Will!

Well, the problem is I practically have TWO components of everything.

I have a TFT and an old 17" (no flatscreen)
I have two computers with two different graphic cards

What also disturbs me is that my old computer, who ran fine just a couple of hours ago now doesn't work, although the configuration of hardware components have not changed at all.

My old computer also had a warning signal if the graphic card wasn't properly plugged in; tried several times, the computer seems to run fine, but I get no signal ...

I just don't know what it could be ...

Will.Spencer · 09-17-2006, 09:16 AM

One other thought...

Are you testing for the "No Signal" condition before the systems boot into Windows? It's best to test for "No Signal" while in the PC BIOS setup.

This prevents "No Signal" problems which arise because Windows puts the video card in a mode which is not supported by the monitor.

Rhadan · 09-17-2006, 09:20 AM

I don't have any chance to go into BIOS - I get no signal right from the start.

Nothing, not even a DOS prompt or anything ...

Currently looking at my old computer, doesn't look like it's even booting, so the problem might be something different there ...

Rhadan · 09-17-2006, 09:55 AM

Tried just about everything; nothing will work ...

Short of taking a hammer and threatening both computers I have no clues anymore ...

Will.Spencer · 09-17-2006, 07:14 PM

OK, let's start from the beginning:

Does either machine power-on?
Do the cooling fans spin?
Are the hard drives spinning?
Are any LED's lit?

trickyrick · 09-17-2006, 11:02 PM

One question I have is are all the components new or are you reusing some from the old system? If you disturb any of the old cards you may have a light coating of corosion on them. once you pull them the contacts in the slots may not line up exactly where they were on the card contacts. The fix is simple for this. Take a $1 bill and briskly rub it on the card contacts. The bills material works great to polish it back to new. Now plug it back in and it should work. It's an old technique used on pre-digital tv barrel tuners. I always do this with all cards and memory I pull and have had excellent results.

Just a tip from an old tv guy.

TR

Rhadan · 09-18-2006, 02:24 AM

Update: I tried the monitor with a laptop, the monitor works fine there. I think neither machine really boots, looks like they have some other issue I can't resolve.

@Will:

1. Yes, both machines power on
2. Yes, the fans spin
3. Hard to tell, but I hear the comp accessing them on power on
4. Yes, LED's go on. There's a big display on the new machine that turns on.

@Tricky:

No, I'm not reusing anything. They are two completely different systems.

I'll try the dollar bill thing on the old one, might be the problem there; shouldn't be on the new one.

Will.Spencer · 09-18-2006, 11:16 AM

This is really weird.

The only time I can recall seeing something like this was an instance of an oversubscribed electrical circuit, causing both systems to fail due to a localized brown-out.

I know this sounds odd, but can you move one or both systems to a different circuit in your house? You will probably have to check your fuse box to determine which parts of your house are on seperate circuits.

trickyrick · 09-18-2006, 12:41 PM

Will might have something there. If you are using a surge protector maybe try a U-P-S to give you a clean stable power source.

Here is another idea. I have seen this many times before. Check both monitor plugs for bent pins. You could hav accidenly bent one or the new card may have a defective female plug and damaged both monitor cords.

Rhadan · 09-19-2006, 01:08 AM

@Will: I tried the computer in the office, and it wouldn't work there either ...

@Tricky: Did check the monitor cable, everything seems to be fine, plus it doesn't matter if I plug in DVI or D-Sub ...

In any case, the new comp is back at the vendor who'll check it (bought it on Friday, so if it's a part that doesn't work they should replace it on warranty).

I'll let you know how that one turned out.

Still trying to fix the old one, but I needed a break yesterday; too much tinkering around.