What version of uLaunchElf were you using? The latest (as I know of) version is v4.42. The older versions had many bugs, so the use of them is generally discouraged.
If your mod-chip is working, then you should not have a problem launching homebrew.
My PS2 is the SCHP 30001 R. It's chip-modded and I can play homebrew/backup discs with no problem. I'm not sure what type of chip they used though. Are there chips that don't work well with ulaunch?
I have not heard of any incompatible mod-chips yet, but maybe some of the more experienced members/uLE devs can verify this.
Older FAT PS2s are picky - They may accept some brands of discs, and not another. This is also true for different products made by the same manufacturer (E.g. there were reports of verbatim CD-Rs not working with early PS2s, but the DVD-Rs are generally strongly recommended).
I've tried several lots of cd iso and dvd iso (even the ones stickied here) and burnt them directly using nero and dvd decrypter on 1x-4x speeds. Still no luck.
Can you please state the brands you've tried?
Don't do that! The CD ISOs are Playstation 2 CD-ROM images!! uLE is a PS2 program, and won't work when the PS2 is in PS1 mode (The garbled/missing SCEI/SCEE/SCEA text is caused by the PS2 being confused).
I loaded them same way I loaded my ps1 games, by holding the reset button. I don't know any other way. Still won't boot up. The playstation 1 screen shows but without the PS logo (just the "Playstation" and the SCEA something). And gets stuck there.
uLE is unable to allow you to load/play commercial games from any other media except from the CD/DVD drive without external software.
I really want to make this thing work mainly to play games from the HDD. So please guys. This is getting a bit frustrating.
BTW: Welcome to PSX-scene!
Unmodified SCPH-77006 with SM 3.6
SCPH-39006 with M-chip modchip, SCPH-10281 NA and refurb Seagate 80GB HDD
SCPH-10000 v1.00 with SCPH-10190 PCMCIA NA and SCPH-20400 HDD unit