Ok, let's go back to square one. Assuming you have the Palomino 1700 with 4 L3s, 4 L4s and 2 L10s. Then yes you did the right thing by trying to open the 2nd from left L3 and trying to close the 4th from left L3 bridges, see below. But now also look at 7.5X in the following...L to R of L3/L4/L10s...
11X = C-C-O-O---C-C-O-O---C-O
12X = C-O-O-C---C-C-O-O---C-O
7.5X= O-C-C-O---C-O-O-C---C-O
"4"  bridges need to be changed to go from 11X to 7.5X, 2 L3s and 2 L4s. How is that possible if you only worked on the 2 L3s needed to go from 11X to 12X, and they are not the same 2 needed for 7.5X.
Something must have gone wrong as a result of the mod. Maybe you did cut too deep and cut some other circuit traces in the substrate below. Best way to open bridges is to "wear away" material gradually with something like a fine pointed diamond coated file, or a rotary diamond coated burr (but used by hand like a file, no power tools). Knives have the problem of controlling depth of cut.
If you confirm that you have a Palomino with 10 bridges as shown, 5 "bridge pairs", (and not a Tbred with just 5 L3s, if there is a 1700 Tbred), then we are out of ideas. Maybe the only option is to restore the mod, easy to wash off the pencil with acetone on a q-tip. But how do you restore a knife cut?? BTW, did you leave the L1s open?? We assume you're doing the mod cause the mobo/bios is unable to change the Multiplier, in which case the L1s should be left open. And if you did close the L1s, did you insulate the pits before closing?? Give us some feedback on these issues and exactly what you did to "all" bridges.
John C.