PLEASE HELP - Lightning, do I need a new mobo?

[CPerret]

Hello all,

We had a bit of a lightning event at my house last week. It took out my internet/phone service (cable), my router, and something in my main computer. I'm trying to determine which part I should order first to get the computer operational again. When I hit the power switch, everything seems to start up - the right lights come on, fans start spinning, hard drive spins up, etc. However, nothing ever appears on the display (I did test the monitor - it's OK). My first guess is that the motherboard is gone (as opposed so some other component). I changed out the video card with a known good one and had the same result, so it's not that either. If the CPU had gotten burned, would I at least get a BIOS startup display, or would the result look the same?

My system is : Intel D875PBZ, 3.0GHz P4c, ATI 9800 Pro, Maxtor 80 GB HD, misc optical drives, floppy, etc.

Thanks for any suggestions on getting back in business.

Chris

 

[Wiseguy69]

Damn... talk about bad luck... that's a nice system. I think that the processor might be the issue. If it is bad, the computer won't even post, but will do the others things you mentioned. The fact that everything gets power makes me think that the mobo may be ok. Then again w/o ruling out the CPU, its hard to tell.

 

[Iron Woode]

Originally posted by: Wiseguy69
Damn... talk about bad luck... that's a nice system. I think that the processor might be the issue. If it is bad, the computer won't even post, but will do the others things you mentioned. The fact that everything gets power makes me think that the mobo may be ok. Then again w/o ruling out the CPU, its hard to tell.

I concur. Test out the cpu first and go from there.

 

[3sixes]

If there is a modem or nic pull them and test mb without them.

 

[rrezende]

I'd start with the CPU as well.

Still, once I had a lightning problem and it fried my power supply and my motherboard got unstable. It would power up, but most times couldn't boot.

After you put your system back, consider buying a UPS. I know APC has good products that do prevent lightning issues.

 

[plewis00]

Even as a 'newbie' to these forums I do use a lot of PC hardware and stuff and I'd like to agree with 3sixes that he is most likely right about the modem or NIC hardware parts. During a lightning storm fragile bits of equipment can get high voltages going down them and especially bits like a modem or NIC which usually carry tiny amounts of current.

I had this once where lightning twatted my modem (PCI) such that the whole PC refused to boot but upon removing and replacing it (with a new card), all was fine again. Also during another lightning storm I had the uplink port blown on my Netgear hub but all the other 5 ports worked fine.

You should probably just remove everything bar the processor and graphics card from the PC and see what happens then. Even so you could try and take it back, it's new equipment, most PC stores don't actually know what they are talking about and will probably just replace it straight off.

I would doubt the CPU had gone, the power surge would have to get through a lot of mainboard circuitry and then the power regulators to blow that. More likely the mainboard has gone then the CPU. Pressing the power switch to see the hard disks, lights, fans, etc. come on implies that the power part of the mainboard works but this would happen anyway even if you removed critical parts like graphics cards, RAM, CPU, etc. so it doesn't tell you so much, though the PSU and mainboard probably work. I hope for your sake it is the modem or something similarly cheap and replaceable.

 

[CPerret]

Hey guys,

Thanks for the replies. As further info about why I think (hope) it's the motherboard... After building this system, I noticed that my Linksys router always showed a live connection to my computer, even when the computer was off. Apparently, the Intel mobo leaves the ethernet connection live for wake-on-LAN detection and the router reflected that. After the lightning strike, the router no longer shows that connection.

I do have a UPS on the system. Unfortunately, the lightning strike came in through the cable line, not the power. It burned out the telephone circuitry in the cable company's box outside. From there, it stayed in the digital cable line that serves my internet connection, passed through the cable modem (without damaging it), out the ethernet connection from the cable modem to the router. It appears to have burned the WAN port in the router and jumped to the closest network port, which just happened to be the one hooked up to my computer. My wife's computer and the wireless access point are OK.

I'm hoping the surge hit the ethernet port of the motherboard, burned out a few key circuits or the BIOS or Northbridge, and stopped there before getting to the CPU (motherboards are cheaper than CPUs).

Thanks again,
Chris