After installing a new main board in my sanyo dp46848 it came on for like 2 seconds then went off and now it will not come on at all HELP!!!!!

I'd start with a new main board, a tcon board could cause it to be blue as well but its not as likely

Could be the main board, power board or Tcon board, take your pick...only way to isolate what one is bad is use a multi meter and test the various power supply voltages and see what is missing or out of tolerance.

You cant find bad caps by just looking

If you wish to get some details; visit the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/

Fault at its main digital board. Short circuited component/s at it. Contact any service technician; or the authorized service center. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
In most cases, the main board might have to be replaced. If so, a software [firmware] update too might be necessary.

Sounds like a main board issue, but please have the set diagnosed properly. Be aware, some Sanyo main boards can be hard to find and costly !!!

What you have is most likely a failed main board. These sets are known for this problem. There are several different variations of the main boards. Make sure you order one that matches yours. The main board part # will start with J4@#. The main board part # should be on a sticker either on the main board itself or on the coax input terminal casing. I hope you got the TV for a good price !!!

You need to replace the top and bottom y buffers when you replace the Ymain. If not, it will just go back out. If you have space, wire a 12 volt mini cpu fan near the left of the Ymain and the buffers, should last alot longer that way.

I was lucky to get a tv repair shop that was a Sanyo authorized dealer to talk to me about this issue.
They told me that they had 3 of these tv's in and they said they were all repaired by replacing "3" parts. they are:

the Y SUSTAIN Board - Part # LJ92-01200a
the Y-Upper Buffer Board Part # LJ92-01202a
and
the Y- Lower Buffer Board Part # LJ92-01203a

I am in the same boat. I amd going to rip the back of my tv off and verify the part numbers. I HAVE NOT REPAIRED MINE YET.. so take this for what it is worth. The Repair shop gave me this info because they were going out of business and did not intend to take any new tv's in for service. The girl who gave me this info read it out of the service repair tickets from 3 Sanyo DP42746 tv's that had the same symptoms as my tv.

Please post back if any one has taken action.