This left me without any means of reflashing. The following are instuctions on how to go about completing a hotswap to reflash the SpiderGX. This would allow you to recover from a bad flash which (like in my case) rendered the chip useless, or an alternate means of reflashing if the web based reflasher is not working.
For these instructions i used a Sundaychip along with a solderless pinheader adapter, similar to the ones xenium makes. The xbox version which was used in my case was a 1.6b, however this will work on pre 1.6 machines as well. (LPC rebuilds are only required for 1.6 consoles)
I chose to rebild the LPC with wires on the underside of the motherboard. I thought the 'spider leg' solution to be a bit flimsy and difficult to install. You do not need to have the LPC rebuilt the way I chose to do the hot swap, however it does make it much easier since you'll be removing and re-installing chips while the xbox is powered on. If you do not have the LPC rebuilt on the backside of the board, your alternate chip may also need to have a solderless means of connecting to the necessary data lines (like the spider leg solution). Now on to the guide:
For this guide we'll need evox installed on a hard disk with the needed bios loaded, and appropriate flash lines added to the evox.ini file. The one necesarry for flashing the Spider chip is as follows:
Flash = 0xc25b,"Macronix_MX29LV800B",0x100000
Adding the lines from the latest version of raincoat.conf from here to the evox.ini would most likely be a good idea (especially if you plan on flashing a variety of chips in the future).
Alternatively, an evox boot cd which is properly configured (with the needed flash id will work just as well).
OTHERGUY'S SPIDERGX HOTSWAP METHOD
To begin we will first need another modchip (which meets the requirements noted above), a hard disk with evox installed and configured with the needed flash line in evox.ini, the bios you'll be flashing to the spider loaded in the evox bios folder and your spider.
Install the working chip into the xbox as per normal, boot up the xbox into evox. (as shown below) When installing the chip, make sure you have two d0 lines avaialble (one to each chip), or have some way of moving the d0 line between chips. If your other chip requires bt to be connected to be enabled (as in my case), dont forget to solder that wire in.
When in evox navigate to the Flashing option. The location of this option will vary depending on how your evox.ini is setup. Highlight the bios which you wish to flash to the spider chip but do not press 'A' yet.
Remove the chip you booted from with the xbox still powered on. Install the spider chip. Make sure the pins are aligned and that the blue leds are light when installed. Be careful while you're installing it. The xbox is powered on and you could very well damage the motherboard if you were to say... drop the screw onto it, so dont do that. Take your time and get the chip fitted to the board.
As you can see in the image above, the chip is installed and the xbox is still on.
Select the bank which you wish to flash. I had mine set as shown below. It appears that evox will flash the selected bank and all consecutive banks with the bios you've chosen to use. This is what i have observed while getting this chip running again. I cannot say for sure however because i've yet to do enough testing. Needless to say, procede with caution. I would not suggest flashing in this manner if there is something you need to save on the chip (whatever that may be).
Once the SpiderGX is in place, press 'A' on the bios you wish to flash to the chip. (as shown below)
Press the Y button to begin the flash. (as shown below). If evox does not recognize the chip like in the photo above, then you have either not installed the chip correctly, dont have the proper lines added to the evox.ini file, or your chip is beyond repair (say thanks spiderchip team).
The flash should erase the chip and flash the bios you selected. Then the unit will power off. IF the flash does not work for whatever reason, start the process over again, try selecting another bank, or double checking your connections on the LPC.
Powering on the unit after a successful flash will result in the bios loading. WOOWEE
Enjoy your repaired and working chip!