Little update: one seller on ali gived some explanation about difference: 1/2 is for LX, 2/2 is for ES/RX, difference in program uploaded. Confused now. Now with bad PCB display board sometime i see "Power consumption" screen and Hybrid scheme, climate screen is also differs from original, after reboot original is250 interface come back.
So program i have on my is250 is not only for this car,

 

It's one of them symptoms of failure power board. You will see it first then later it will be black out again.

 

1/2 or 2/2 is just the REV of the built. The matter is what program did they loaded in there.

 

Thanks whitebeast for help!
Ordered used 2/2 board from ali (just used found)
On photo - my bad board. Tried to warm up (from both sides simultaneously) main cpu (one under fan) and some BGA chip (on photo), replaced thermal paste. Aaaand... no results.
So i will try to add more thermal paste to cpu on ordered board.
Hope this board will fit my navi ^_^

 

Board came from ali yesterday. It fits perfectly, and all working fine for now (no any reboots or freezes etc...). Menu and functions same as with 1/2 board. So, if anybody needs bugged board - welcome ))

 

So just so others with this problem know, what was the part that you purchased and replaced in order to fix the issue?

 

I know exactly what causing the problem cause I've been repaired more than 30 units like this already. The heat you applied to the BGA is not enough to fix the solder (water soluble -lead free) for BGA.
For anyone want to take care of the blank/black screen problem. Go a head and order the display driver board, your problem will be fixed in no time.
hereis some picture of it for your reference

 

So if someone wants to replace this board, do they need to look for P/N 462651-0012? Just trying to help others down the road.

 

Not really, They are 3 different part # but all of them should work fine as long as the program loaded is for IS. You should as the seller will it work for IS before buying it.

 

whitebeast, you say that the problem is in BGA main chip soldering, how you find this? And if it possible to find naview new cpu and reball it, will it fix this problem?

And for all others with this problem:
462651-0012 (1/2) is the same as 462651-0012 (2/2)
But be careful, i found on ali seller with this board (same as mine with (1/2) code) and compared images of this board sent by seller: on the other side of board (where is no fan) placement of SMD-elements and other chips differs from my broken (1/2) board...

 

first at all, I do have somebody to X-ray the BGA. Second, i do have system to do schematic on the board to find out what other component causing the problem. In some case, The IC and memory also could cause the problem.

 

Recently purchased the car, similar issue the screen would work then would go black and says check system, but i don't have the original dvd disc for navi in it, could it possibly be the cause, radio works. Sometimes it would randomly come on for little bit but for the most part be off. P.s. is the a place where i can buy navi dvd for 2006 lexus is250 thanks.

 

Well, the problem you have is not the same. We are talking about the whole top unit went black, No A/C control or none of the buttons light up at night.
The problem you have is MAP ECU failure, This should be easy case and less money to fix it. You could also buy the NAVIGATION PLAYER to replaced your failure one.

 

@whitebeast , i change the powerboard but i got error that the pogram cannot be read

 

The program cannot be read error means your Map ECU drive not working any more. Replace it and you good to go.
It also called navigation player
http://www.ebay.com/itm/06-07-08-09-...%257Ciid%253A1