HI the knowledgeable ones..... after a little advice please

I have a 10b G3 that had the screen shattered - powers up but bad as you can guess

I bought another off of ebay that had software probs for spares and screen worked

I have swapped over the boards and wired it all back up but now I get nothing -

H ear the unit doing a few clicks n stuff when power hit and the screen seems to dimly back light but still nothing. but this is on both units the same even the cracked screen version with the iff board in. I could at least see the arnova boot screen before

On supplying power I get the red charging LED on

I have gone through all cables and everything seems as it should be

any ideas plesae to go forward other than scrapping them

thanks