"No Signal Detected" on Monitor

[everton66]

Hi. My dad is getting a message about no signal being detected when he switches his PC on. The monitor is a small flat screen TV. The monitor works OK with other inputs and we have tried with a different monitor cable, but we still keep getting the same message.

Seems to me that we have ruled in the fact that the issue is at the PC end? How can I check?

Thanks.

PS - it is using onboard graphics.

[bouncingjohn]

Does the monitor have both analogue and digital inputs? If so he may need to select the correct one using one of the setup buttons on the monitor. Need a bit more detail really to be more helpful (e.g. make/model).

[centaur]

Usual suggestion is to substitute a known working alternative screen if poss. If this works ok the problem would appear to be either in the 'puter, possibly graphics card or the cable. If the sub doesn't work, same problem.

[everton66]

Its got onboard graphics. If the problem is that is it possible to add a cheap graphics card to remedy the situation? I'm wondering how I turn off onboard graphics in the bios if I cant see anything on the screen?

[Mender]

Stupid question, but has he actually selected VGA input on the TV itself?

[everton66]

Tried every input source. It's worked fine on the "PC" setting for about a year. Now we get nothing. Nothing on any other input source either. The back of the monitor is fairly straight forward. Everything is labeled and the socket for the monitor cable is marked "PC" which corresponds to the input source. Worked fine one day and then didn't the next.

[silver]

perhaps the cable is broken unless you tried switching that out already?

[everton66]

Yeah - tried a new cable and tried the monitor on Sky downstairs and it works fine. What are the options? Will a new graphics card work OK given that it seems to be a problem with onboard graphics - does that imply a motherboard issue?

[Mender]

If you connect a different monitor to the computer, do you get a picture? If so, it sounds as if the VGA input on the monitor is faulty.

[everton66]

Hi all. Right - we have attached a known working monitor to the PC and we still have the issue. It's not the monitor and its not the monitor cable - it has to be the PC, correct? What are the options. It doesnt have a graphics card - it is onboard graphics.

Thanks,

[Mender]

First thing to try is to reset the BIOS because something in the BIOS settings may have become corrupted and causing the video problem. On the motherboard, very close to the BIOS battery (a small silver disc about the size of a 10p sitting in a plastic holder), you should find a set of two or three link pins with a connector sitting across two of them. Remove the link for about a minute, then replace it is the same position and see if the computer gives a display when you switch on.

If that doesn't help, then the next thing would be to try and borrow a graphics card to see if it helps. If it works, then you know you need to buy a card.
If it doesn't work, then probably the motherboard has gone faulty, and would need to be replaced.

[everton66]

Ok thanks Mender. Will give it a try. Don't know anybody with a graphics card so may have to buy a cheap one. If it is the motherboard, is that a new computer or is the motherboard cheap to replace?

[Mender]

You can just buy a new motherboard, which would be cheaper than a new computer. Most importantly, the motherboard you get must support the CPU and memory from the old one.
One problem though, unless you can get hold of an identical motherboard to yours, it is unlikely that your Windows will work as all the motherboard drivers and hardware addresses will be different.

However, there are ways around the problem, but you have to mess about a little bit to do it.

The first, and most obvious way is to format the hard drive and reinstall Windows fresh, but the downfall is that you lose everything you have installed, and any data files you have saved on the C : drive.

Then there are a couple of ways to do it without reinstalling Windows. A bit fiddly, but at least you shouldn't lose anything off the hard drive. Full information is available on how to do it. Copy the line below and paste it into Google. The first two links in the results will give you two different methods.

replace motherboard without reinstalling Windows

Hopefully though, a graphics card will sort it for you

[everton66]

Thanks Mender. I will let you know how it goes.

[everton66]

Ok. More information - seems I misinformed you.

I took the cover off the pc and I established that there is in fact a graphics card being used. I swapped the graphics card for a card I know works, but there is still no signal on the monitor. I then put the old card back in and it worked! I happily put everything back together, and then it stopped working again. Seems like an issue with the AGP slot?

The motherboard is old and has a 9 pin monitor socket on it (onboard video I presume). I bought 2 adaptors from Maplins to convert the 15 pin monitor cable into the 9 pin monitor plug. I removed the battery and the jumper switch Mender referred to to re-set the bios, hoping this would switch the onboard video on. Despite this, there is still no signal being received on the monitor.

I am thinking that now I need to buy a PCI graphics card, unless there are other suggestions?

Thanks.

[silver]

if you can get a screen working then goto the bios setup screen - there it can be set to choose which graphics to use (onboard / agp / pci) normally at least

card might just be loose if it worked then stopped when putting on case,. make sure it is properly seated - think agp somethings has a locking catch on some mboards (not sure)

[everton66]

Tried all that Sil. Card is firmly seated with locking catch in place. I cant get anything on the monitor at all.

[salzen]

Hi, if this has still not been resovled there are several very quick fixes for a blank screen.

1: Remove all pci cards, clean the pins (warm water with a touch of fairy liquid will do), remove any dust from the socket (short sharp blow or with compressed air)

2: Remove your memory modules and do the same as step one.

3: Firmly reseat all.

This is just as commonly a RAM issue as a video issue. So please reseat the RAM as well

[Memfis]

Sorry Salzen, but I believe you are incorrect here.

The card is detected so it's not a connection problem. Besides I'm sure the friction of reseating a pci card or ram would clean the pins sufficiently - I would not recommend washing them!

[tommy t]

well as no one has suggested it, it maybe the power supply giving in, depending on the mobo,if you remove the gpu from the pci slot and try booting up with the gpu not fitted it may auto sense that no pci gpu present and switch to on board chip for graphics, if it powers the monitor there is a good likely hood that it is the psu, the graphics won't be great and you may loose whatever resolution you had it set to, hope this helps,