ECS's web site is out of date about CPU-motherboard compatibility, but
even it says that an XP2600+ will work in the oldest Socket A
motherboard listed there.
But before replacing it, check the board for damage or a new CPU may
be instantly destroyed. Look for obvious signs, such as burn marks,
discolored power transistors (their black epoxy bodies turn brown or
grey when grossly overheated), bulging or leaking electrolytic
capacitors (aluminum cylinders covered with plastic). Such parts must
be replaced before the board can be used again, and if any capacitors
are bulgling or leaking, replace every one in the voltage regulator
circuit -- see www.badcaps.com for more information.
Bad capacitors often appear normal when tested with an ohmmeter or
even a capacitance meter, and only an ESR meter may detect them, but
an ohmmeter can completely diagnose bad power transistors and diodes.
See www.repairfaq.org for information, but realize that most computer
technicians aren't qualified to do electronics repairs (and that one
seems particularly unqualified). If you live near a Fry's
Electronics, look into buying a whole new motherboard with CPU because
almost every week they have a low-cost combination for only a little
more than a CPU alone may cost. Newegg.com sometimes has similar
deals.

I wouldn't flash the BIOS unless I knew for sure that it would prevent
a new CPU from working, but if you ever need a boot disk for this, see
www.bootdisks.com.

I've never seen the K7S5A ver. 1.x, only the 3.x, but according to the
ECS online manuals the most visible differences are in the BIOS chips.
The ver. 3.x uses a 32-pin rectangular chip with 2 rows of pins
(socketed on the ones I've seen), while the ver. 1.1 has its BIOS in a
much smaller chip that appears to have pins on all 4 sides of its
package, possibly soldered to the board. Otherwise the layout looks
very similar, right down to the positions of the header pin sets. The
K7S5A discussion boards at
http://pub65.ezboard.com/bk7s5amotherboardforum should have more
information.

This board has a 32-pin rectangular chip so I assume 3.x as apparently the
Pro board is plainly marked. No signs of damage to board visible. Thanks for
the ezboard link! ~Dr.J.