(Tsuno wo tamete ushi wo korosu; “Straightening the horns, killing the cow”)
A situation where trying to fix a small problem ruins the whole thing. The cure being worse than the disease. Hammering and pulling on a cow’s curved horns in an attempt to straighten them is only going to be bad for the beast itself.
This saying comprises conjoined verb phrases. The first begins with noun 角 (tsuno), “horn(s),” marked by particle を (wo) as the object of verb 矯める (tameru), “to straighten,” “to correct,” which appears in conjunctive form. The second phrase uses を to take as its object the noun 牛 (ushi), “cow,” and the verb being done to the cow is 殺す (korosu), “to kill,” in conclusive form.
Replacing 矯める with homophone 溜める, “to amass,” is of course an error. Replacing it with 直す (naosu, “to fix”), however, is perfectly fine.
This saying has a surprising number of synonymous phrases. My favorite are the ones declaring that trying to repair or polish a Buddha statue, or a Jizou statue, will break off its nose.
(“Tsuno wo tamete ushi wo koroshita you ni, sofuto ni chotto dake te wo kuwaete mitara, tochuu de pasokon ga fui ni buruu sukuriin ni natte shimatta.”)
[“As if I’d killed the cow by straightening its horns, when I tried tweaking the software just a bit, all of a sudden my computer went BSOD.”]