Inspiron 9300 replacement board can i downgrade the Bios?

Hello folks, this is my first post so a quick hi to all of you and thankyou for many solutions in the past which have spanned from this forum.

Well i have had to bite the bullet and register so i can ask you guys for help...the story goes...

Ok i receive a laptop Dell Inspiron 9300 from a friend who has dropped it (well he says the kid knocked it off the couch and then to add insult to injury he followed it over and landed on it) well needless to say i diagnosed that the motherboard had failed as i ran the system from a barbones state to rule out any hardware failures. So i ordered a replacement board from the big old bad Ebay guy that hangs around the internet...So i rebuild the laptop plug it all in and turn it on.. so far so good i see the Dell logo and select to enter the bios to which i see "entering setup"... now instead of going into the setup i receive only this...
"The ac power adapter cannot be determined. The system can only boot with a 130w power adapter or greater"
"Strike the F1 key to shutdown"
Now after browsing these forums i see a lot of people experience this issue and purchasing a 9 cell battery with a 130w AC adapter will work ... BUT... if at all possible he does not want to spend out any more cash as i assured him the replace board would work. Well at least i was correct in diagnosed the bad board lol. Now then the help i need is reverting the bios from A05 to anything that will let me use the 90w adapter and the 6cell battery that is already installed, as i cannot get to the bios to select the boot from cd option and hitting f12 for the 1 time boot menu just takes me to the same error with no other option but to shut down with the F1 key.
I found a little about using a bootable usb to downgrade the bios but i would like more information on this subject as in how to prep a usb to make it recognized as a bootable device without any bios options to play around with.
Can anybody help as i need to tell this guy some good news as he has spent a wad of cash in an attempt to have this laptop repaired and i feel as if i have let him down bigtime if i ask him to fork out another wad of cash for the ac adapter and battery
Thankyou all for reading and appreciate any help you may be abl;e to suggest
Kindest Regards
Tony (aka Tigertunes)

Yes i do beleive the board in question must be flashed with that bios, am i right in thinking i am going to need to do a blind flash via usb as i cannot reach an option to boot from CD then the boot disk will not load?

I completed the bootable usb earlier and put the I9300A04 bios for the 9300 but i am arriving at the same "strike the f1 key to shutdown"
The ac adapter i am using is actually a 150w Dell which i thought would do it when i first got this part of the same message "the system can only boot with a 130 w power adapter or greater". I also have the original 90w that came with the laptop which when i first encountered the problem but same results.

So is it unavoidable that i am going to have to purchase this ac adapter then you think ?

Hey again and yes have tried that but it tells me the system cannot be booted from the battery so i assume this is because it is a 6 cell, i cant bring myself to phone him he was all exited about getting his laptop back this weekend i think i might leave the country cause it feels like i have let him down. I mean noone expects to have to purchase a new ac adapter and battery with a replacement board i have fitted many any never had this issue. Tell me i wonder is the security tag that the 9300 recognizes removable at all from the ac adapter because i was wondering whether i can move it into this 150w dell ac adapter, is this an avenue worth exploring do you think ? I know they are pretty much sealed units but that has not stopped me in the past refurbishing batteries hehe

Hey thanx for all your advice by the way its mucho appreciated
Now i just thought on i have another laptop here with bios problems i wonder if i could chew on your ear about another case concerning the bios.
Ok this is another friends laptop that has been here for a few weeks but it seems toast, he told me that he lost power during a bios update and it hasnt booted up since, now i havnt seen this guy in a while and he didnt know that i was able to repair laptops so he actually put it into the shop for a quote, i assumed he explained the situation to them and left it there to be diagnosed, now i have no clue how they came about the diagnosis but they gave him it back and told him it needed a new screen and it would cost £200 lol, just another in a long list of crappy and incorrect quotes from poorly managed repair shop, i seriously need to start charging people for repairs lol i have fixed soo many for free but i have to say it has taight me a lot over the last few years. Anyways that aside i have actually removed the screen and the bezel and tested the screen on another machine and low and behold the screen is fine, i told him to take it back and ask them to replace the screen just to buzz of them when they wast £100+ on a new screen hehe. Anyways the laptop is a Acer Aspire 3690 and is a pretty decent machine, i have found a couple of threads around the net about a method to reset the bios on acer models but they dont seem to work. It actually powers on but nothing at all is displayed on the screen and it doesnt seem to respond to any normal functions you would perhaps use during a boot up, i have tried bootable diagnostic cd,s and also your amazing bootable USB drive which is now and i am sure my newest and most powerful weapon in my arsenal hehe

In essence i would like your professional opinion as to whether you think the bios can be reset after a power failure during a bios update, i have actually removed the board and unsoldered the bios battery and left it for a few hours after draining all the capacitors but to no avail, do you think perhaps a longer time with bios battery removed from the board will make a difference or shall i spread some butter over it and present him it back as nothing more than his new and expensive piece of TOAST hehe

Thats actually not a bad idea, unfortunatley the chip is soldered good and proper onto the board and i dont have the tools to remove one, thank ya though

Well it looks like i am going to have to bite the bullet and buy them, i think to cut down on losses i will buy them for the sole purpose of reflashing the bios then resell them and carry on using the current battery and adapter, it may be a bit more of a wait for him and i will pay for the stuff for him, now all i have to do is in a very professional manner "try and duck him for a week" lol.
Thankyou for all your advise and assistance in this matter, i am just happy to put the thing away until the adapter comes now , its been nothing but a headache this thing hehe.

Apologies about my other enquiry i should have properly read the rules and will absolutley repost that question in the relevant forum.

Thanx again buddy i will let you know how i get on when the adapter arrives through the week
Kindest Regards
Tony (aka Tigertunes)