Asus m4a785m motherboard - had lightning strike and computer shut down - jumped on/off sw with no results and then changed power supply with new unit. Still will not turn on. Acts as though no power from wall. Changed with known good power plug and wall outlet. Still nothing. Help please

The damage from a lightning strike tends to be random. Sometimes it's minor, and only a few parts are affected. Other times, many parts are ruined, or destined to fail soon as a result of the current surge.

If the strike came over the power line, the input surge protectors in the power supply should be replaced, even if they look good. It would be prudent to replace the entire power supply. If you had the set plugged into an external surge protector, that should have taken most of the hit and should also be replaced. (Some surge protector manufacturers will pay up to a certain amount for repair or replacement of equipment plugged into their products if it is damaged by lightning.)

If the lightning came over an unprotected input cable, fixing the set would be a gamble. You could end up changing a lot of modules, beginning with the main board.

William,

http://www.asus.com/Motherboards/AMD_AM2Plus/M4A785M/

Motherboard Manual,

http://www.asus.com/Motherboards/AMD_AM2Plus/M4A785M/#download

Click on the + sign next to -
Manual (7)
Scroll the inside blue bar down to the right, and click on the blue -
Global, under;
Version E4937 - M4A785-M user's manual (English)

This is a Zip file. If you do not know how to download, and 'unzip' a Zip file, post back in a Comment.

The CMOS battery is a CR2032.
It's holder is located under the Ram Memory slots.
There is a spring steel ring, going about 9/10 the way around the battery.

In the small space that is left, is the Lock that holds the battery in.
The Lock tab is brought to the Outside. This releases the battery. It pops up a little, and you 'fish' it out.

A toothpick is about the right side to use, but will break. I use a computer pick, but do not advise using it for the first time, at this.
One slip with a metal tool, and you can damage the motherboard.

ALWAYS make sure the Positive ( + ) sign is facing UP.

For additional questions please post in a Comment.
Regards,
joecoolvette

Most likely something beyond the power supply has been damaged by the lightning strike and will have to be repaired by a service center.

All I read properly .Please remove power supply from HDD and CD /DVD RW. If you face the same problem Open the mother board on a open place and try it again ,because there are some particles witch has made the short sercit in your M. Board.Cgeack all voldage socket plkaced properly,MAY BE CAN SILLY MISTAKE FOR 4 pin socket .


If you face same problem please install in another mother board .Post me please imediate next result.

The MOBO is one thing and the POWER SUPPLY other. The power supply has his own cable to connect to the MOBO>

get a sound card and install it + some speakers
hope this helps

power surges generally damage power supplies or mother boards
smart operators use surge protection board or UPS unit s to lessen potential damage
Take it to a repair shop for a diagnosis

hi , by your description i would say the relay in your power supply is deffective , its not a cost effective repair , so change the power supply

hope this helps

i read an forum, mboar asus shutten dwon NOT avaible.

Hi tenbear8, I checked the bios date for the motherboard. I'm guessing this board came out in late 2005. Asus warrants their boards for three years. With this in mind it’s worth a call to Asus tech. Open you're case & find the white sticker on the LPT port. Write down the information there. Call Asus M-F 8:00AM to 5:00PM EDT. The number is 1-812-282-2787. You will not be on the phone very long before a tech picks up. (Free support).
The tech will want the information you wrote down from the sticker.
In the mean time update you're bios with the latest flash.
Bios number 0809, it has a fix for CPU string correction in the bios. It may just do the trick.
Click here for the link to P5VDC-MX download site.
http://support.asus.com/download/download.aspx?modelname=P5VDC-MX&SLanguage=en-us
Download the bios file & download the Bios Utilities.
Either way it will not hurt to call Asus even if the bios flash fix's the system. The more information you can get from Asus the better. (They know their boards better than anyone).
If you're board is bad Asus will know & if it’s still in warranty you're looking at receiving a replacement board. Nothing to loose & everything to gain.

Good luck tenbear8!
Please let me know how things work out with Asus.

Mike