Did a little research and here is what I found.
The new v5 boards are the ones with the new laser and DVD drivers. There is also another new chip in these systems. This is copied from another (credible) website:
I have read other places that the 3003R machines are all v5 boards. Whether or not this is correct, I'm not sure.
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Recently it was brought to our attention that a new PS2 mainboard design is starting to make its way to retailers. This revision is being labeled the PS2 v5 board as the last major board update was the PS2 v4. Please note that the "GT3-Package" PS2's have either a 3000x or a 3500x model number, however their mainboard is still a v4 design.
A few notable differences with the PS2 v5's are that they include the latest DVD drivers and also a better quality laser which reduces the need for tweaking it when installing a mod-chip. The PS2 v5 mainboard also utilizes a new decoder chip which is an FBGA chip.
Several individuals assumed that because of the new decoder chip design (which is unlike the old decoder chip) the PS2 v5's were not going to allow for mod-chip installation due to a lack of pins to solder to. This is simply NOT true.
We have already received numerous confirmations from credible sources that alternate solder points ARE available already... so the upgraded firmware may be the only potential obstacle at this point in time.
For those wondering how to tell if your new PS2 is a v5 or not WITHOUT voiding the warranty, you can check to see if this screw exists by simply popping out your PS2's expansion bay cover. If it does, you likely have a PS2 v5... if not, then your new PS2 probably contains a v4 mainboard.
We should also mention that many of the PS2 v5 model numbers which have been reported thus far have been labeled as 3000xR, however this is NOT a "sure-fire" way to determine whether your PS2 is a v5 or not!
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