I am sure some of you guys will have experience of this problem

So I have an ASUS M2N - NM/S motherboard here. It won't boot, it has continuously repeating long beeps. The user manual does not mention that error code but I think it is related to the video card. I tried several PCI-e cards to no avail, however I did notice that without a video card fitted the long beeps start after a few seconds but with any video card in the PCI-e slot the beeps will start after about 20 seconds or more.

I suspect faulty PCI-e slot and the pins do look somewhat corroded. Also I have a similar problem with the DDR2. With a known good stick in slot 1 I get the repeating long beeps (same with no RAM fitted) but wit ha known good stick in slot 2 I get one long beep then the CPU fan slows down to idling speed. Looking into DDR slot 1 I can see one pin is green and corroded so I think that may be another problem.

As I am am very interested in learning component level repair on mobos and GPUs (I already have decades of experience of electronics repair but not computer PCBs apart from a couple of HDD controller boards) I thought this would be an interesting fault to try and fix for educational purposes.

I have some PCI graphics cards (known good) back in the UK so I will bring one of those back with me when I visit the UK next week as I would like to try the PCI slots on this mobo to see if I then get video output. It doesn't have onboard VGA.

Another thought is there could be a problem with VIA VT6308 QFP chip in the bottom right corner - there is some corrosion down there and that chip I did find a datasheet and it says it is a PCI controller - maybe it also controls the PCI-e, I didn't read the datasheet thoroughly. https://datasheetspdf.com/pdf-file/943196/VIA/VT6308P/1

PS why does the thumbnail display correctly on this forum as landscape but the large image display as portrait??? - at least on my PC