Finally I bought another 604 that had 2 plugins unlocked. Also the seller copied both plugin files on the device before shipping. So I reproduced the same trick as for 504. Beside that, I found and restored old firmware files on the drive. Those were versions 1.1.00 and 1.1.00 b. The latter one seems to be a beta version. Also there were some other firmware files that were overwritten with the one I recovered from the Recycle.bin hidden folder.
Interestingly, there also was a file called a604_prodtest_2.05.aos and was built on 07.06.2006 at 17:52. Its size was 1556 KB only and it was signed with the signature. I'm wondering what it was intended for, but it was hopelessly lost due to having been overwritten by the 1.1.00 file at the factory.
There also was a file that was built on 07.06.2006 at 17:32 (20 minutes before the above one), the size was 12787 KB. But that file didn't have Archos signature and I guess it was used for earlier versions of bootloader that didn't require a signature for flashing that firmware. Therefore I failed flashing it even after downgrading to 1.1.00.
The whole process is going to be a pain in the ass, so get ready seriously.
If you want to use my plugin files, you will have to downgrade your bootloader to make it accept a hard drive with a different serial number to make the device generate an appropriate product number to run the plugin files. In order to do the downgrade, you will have to go through the steps:
1) Pull out the hard drive from your Archos 604 and attach it to your PC via an "IDE 2.5 -ZIF" adapter.
2) Copy an older version of the hidden system partition image to the hard drive with "HD Clone".
3) Copy a firmware file not newer than 1.4.03 and connect the hard drive back to the device, run the firmware file to do the downgrade.
4) Now you need to have a hard drive with the following serial number: 36547612T. The only drives that can let you change their serial number are Western Digital. Get the cheapest IDE drive and attach it to your PC via "IDE 3.5 to IDE 2.5" adapter. No "SATA(USB)<-> IDE" adapter will allow you to change the serial number.
5) Run WD Marvel 2.3 to change the serial number to 36547612T.
6) Copy 2 plugin files to the hard drive.
7) Attach the HDD with a handmade IDE 2.5 to ZIF adapter (see the picture below), connect it to the 604, hook up 5V to start the HDD and turn on the device.
Run 1 plugin file, after reboot run the other one.
9) Install the original HDD back into the 604.
DONEYou will need:
1) HD Clone
How to unpack HD Clone: the main archive file WD_Firm.zip (password: ☤ﮝﻻ⋩ﻛԷ따덕ڦ㏶쳥) contains another archive file called Firm.zip (password: ☃✧〠Ⓙ〶✰ǬⓆ). Unpack the file Reports.rar from Firm.zip and change its extension to exe. Then run it to install the program. If those passwords don't work just let me know.
2) WD Marvel for Windows(x32)
If you want to run it under Windows x64, you will have to disable driver signature check. The easiest way is to press F8 before OS boot and disable it there. It will only work for the current boot. Then, during the first start of WD Marvel an error will show up. Just run the program again.
This is a hidden system partition image of the firmware 1.1.05 for downgrade.
This is a hidden system partition image of the firmware 1.6.53 to use the latest OS version with the downgraded bootloader without HDD being locked down to the device and also to install the plugins.
This is a very old 126.96.36.199 firmware file for downgrading the bootloader.
6) cinema_B7JB6WDH25S45F (604).zip
6) videopodcast_B7JB6WDH25S45F (604).zip
Videopodcast pluginHOW TO DOWNGRADE
Take out the hard drive and connect it directly to PC with a ZIF to IDE 2.5 adaptor.
Run "HD Clone"->Restore partition->choose the folder where you unpacked 1_1_05(604).zip: first click on the needed drive on the left panel. Then using the right panel go to the folder with the needed image folder and click on it-> click Next (if the button is not active, it means you didn't choose the image)->in the next window "Target partition" click "Show all partitions" to uncover the hidden partition->find the hard drive of your Archos and click on the smaller partition called "unnamed". Its size has to be around 97MB->click Next->Start->Start copying->(Waiting)->Automatically->Quite HDClone.
Place the hard drive back into Archos and start it. Choose "repair" if recovery menu appears. Then use 1.1.00 firmware file to downgrade the bootloader.
TO DOWNGRADE FROM 1.6.53 IT IS IMPORTANT TO HAVE THE DRIVE, WHICH IS LOCKED TO THE BOOTLOADER. IT HAS TO BE IN A WORKING CONDITION. You will have to use exactly that drive (I mean you have to use the serial number from the drive, which archos has locked down to its bootloader) to downgrade. Because another drive will not be accepted. You can buy an old most cheap Western Digital IDE HDD. Then just use WD Marvel to change its serial number and do like I've just described. Before using WD Marvel you should disable the hard drive in Windows device manager.
Don't forget to copy the serial number of your drive into some notepad or anywhere else. It will help you so much when the drive dies.
Remember: if you upgrade to 1.4.07 and later then the bootloader becomes locked down again.
I would also recommend to have a backup Western Digital HDD with a needed serial number and firmware below 1.4.07 installed on it.
This way gives you a chance to install an SSD without changing its serial number.
After downgrading the bootloader, you can use any hard drive to work with your 604. Now you can install 1.6.53 by using my 1.6.53 image in HD Clone without upgrading the bootloader.HOW TO UNLOCK BOTH PLUGINS
First you need to get any 2.5 Western Digital IDE hard drive to change its serial number to make 604 accept my plugin files.
Now you need to make your own ZIF to IDE 2.5 adapter because there's no such one on the market.
I bought this one
And I replaced the male IDE connector with a female one. I took it off from my dead Archos 504
The ZIF connector should be inverted in this case, so I removed the connector and attached a ribbon that was coming with the adapter. Now I have an adapter, but it needs power for the HDD. So I attached external 5V.
It works fine with my Archos 404.
Before connecting the HDD to 604 with the adapter, you should change its serial number to make 604 accept my plugin files. To do that, run WD Marvel with the HDD connected to your PC with the ZIF to IDE 2.5 adapter. And follow the steps shown on the following pictures:
The serial number should be changed to 36547612T. After doing that, just press Enter and close the program. Don't forget to copy 1.6.53 system partition image with HD Clone and unpack the plugin files on the drive. Now the hard drive is ready to be attached to your 604. Attach external 5V to the adapter to start the hard drive. Turn on your 604, connect it to the power source to install the plugins.
Now you can install your mini hard drive back. The plugins are unlocked forever.