If you are trying to revive a A4000D the very first thing I would do is open her up and check/remove the NiCad battery next to the SIMM sockets! If there is leakage you are 99% guaranteed to have RTC problems and if worse Fast RAM problems. Even if there is no leakage I would highly recommend you remove that NiCard battery now and install a NiHm type or better yet do the Lithium Hack! (See my photo gallery)
Things to do:
1. Remove the Battery!
2. Get a larger 7200rpm IDE HD (20GB or 40GB will be ideal)
3. Get a fast IDE CD-ROM Drive (Lite-On are good)
4. Install Kickstart 3.1 ROMs
5. Buy AmigaOS 3.9 CD from your dealer!
Have fun!