Gateway gt5678 crashed

Troubleshooting:
1) Remove the side of your case.
2) Try to START your computer and observe the CPU fan.

If the CPU fan isn't moving then your problem may be:
-CPU fan
-motherboard
-PSU
-cable connectors not seated

If the fans ARE spinning and things sound like they're starting up it may be your monitor. If possible, try your monitor on another computer.

If the HARD DRIVE was dead or removed and the only issue you'd still be able to go into your BIOS or boot into Memtest or a Linux Live CD.

Without knowing your exact symptoms I'm tempted to say the PSU or motherboard which are unfortunately a pain to troubleshoot. You'd have to SWAP them.

If your troubleshooting the hardware, try removing anything absolutely unnecessary which includes the hard drive, floppy, DVD/CD drive etc.

I will check the fan to see if it is running. If I understand correctly if I disconnect the hardrive it should still go to the bios screen. I will check these things when I get home this evening.

I checked the fan and it starts running as soon as you hit the power button. The fan continues to run until you push and hold the power button to shut it down. I am going to try the moniter on a different computer. Anyway to check the motherboard or the PSU. I tried to check all the wiring connections and it didn't make any difference. Thanks for your help

I also checked the moniter works great on a different computer.

Any help. any one know what I need to check next or how to check it. do I need to post in a different section to get help with this problem? I appreciate any help given.

Same thing just happened to me too. Gateway GT5678. My wife was using it and the screen just locked up on her. Mouse and keyboard non-responsive. I did a hard power-off just as the OP did and got the same results, all fans run and the power light comes on, but no PC activity. My monitor works with another PC, and I pulled the HD out to recover some files for my son's homework, and it works fine, too. Two months out of warranty. Gateway wants $60 for 30 minutes of tech help for me to tell them my computer has bricked itself. Not good!

I think the motherboard is bad but I can't get any info about how to check it.

I have the same issue

I was able to boot for a little while with VGA connected, when I IM'd gateway he had me drop my resolution to 60 mhz. Now I can't even boot and see the bios

I removed the video card and replaced it with a known good one and it still doesn't work.

I've tried two different monitors and 2 differnt monitor cables (vga to dvi connector and dvi to dvi) No luck  

I'm getting no diagnostic lights on the pc

I even reloaded the os when I was still able to see the screen in vga. No luck.

Was there an update on or around Aug 2009 that blew these motherboards?

You're all not alone. I also experienced the same issue last night with my Gateway GT5678. Screen froze and had to do a hard shut down.

I have removed all cards, memory and processor...fans will start so it has power but it doesn't even attempt to go into BIOS. No beeps and no data being received by the monitor whatsoever.

Bad circuitry on the mobo? Not sure but I'm pretty sure it's the mobo at this point.

I find it funny that the only way you can get to Gateway's tech support is through email or online chat....   Try calling the number listed on the Gateway computer...number is disconnected or no longer in service. Sad.

Same thing happened to me...no video, and everything else checks out fine. Does anyone know of a good solid compatable motherboard to replace this defective one?
Thanks

If you figure something out, please let me know. I am experiencing similar issues with my Gateway GT5678, but not as major. The screen will turn off after 20 minutes when i tell it too, i do not tell it to sleep or hybrid sleep ever, and i will come back to my computer and it is unresponsive. I have to do a hard shut down, reboot and it asks me if i want to start in safe mode.

I installed 64 bit W7 on it a while back hoping this would help solve the problem.

Really looking to get a new case, MB, power supply and video card and just use the dvd drive and cpu.

Anyone have suggestions on a motherboard and/or video card for this machine???