Problems with ZipGS Upgrade

[cptfa@aol.com (CPT FA)]

I followed the CSA2 FAQ on Accelerator Upgrades and tried mine.  I had a 7Mhz
ZipGS with a soldered oscillator (28Mhz Full size).  I desoldered it and
installed a 14 pin socket then replaced the 28Mhz with a 50Mhz oscillator (Full
Size).  When I reinstalled the card and powered up all I got was a black and
white checker board screen.  When I removed the card and replaced the oriningal
CPU chip I booted up just fine at 2.8Mhz :(.  Here's my questions; have I
ruined my board?  Is there anything I can do to fix it?  Is there anyone out
there that can do this upgrade/repair?  Thanks in advance for any assistance.

Leif