On Sat, 15 May 2010 03:58:41 -0700 (PDT), Merciadri Luca
wrote:

Tear them apart and clean the guts with a dry paint brush. *It
probably has some corrosion damage from the soaking.

Done, nothing better.

Did you actually take it apart? Here are HP's useless disassembly
instructions (for recyclers):
http://www.hp.com/hpinfo/globalcitizenship/environment/productdata/Countries/_MultiCountry/disassembly_calcul_2006813145716.pdf
Try washing it again with CLEAN water to remove any contaminants and
salt crud. Use a paint brush for cleaning. Use an air compressor and
air gun to blow off as much water as possible. Let air dry for at
least 24 hours. Try again.

Also, there are 8ea HP-30s calculators on eBay for an average prices
of about $15/ea.

Yeah, I know, but I even have a HP-50g, which is clearly better. That
is not the problem. The problem is that I like(d) this calculator.

Yech. It's really an HP relabeled Kinpo calculator.
http://www.rskey.org/detail.asp?manufacturer=Hewlett-Packard&model=HP-30S
There's no exact equivalent but this is close:
http://www.kinpo.com.tw/English/Calculator.htm#sr19d1

This self test might be useful:
http://www.rskey.org/~mwsebastian/selftest/hp_test.htm#hp30s

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558