Diagnosing RAM Problem

Hi,

I was given a non-working C64 recently with the "?OUT OF MEMORY ERROR IN 0" problem. Through my interweb research this most likely points to a RAM issue. My C64 has the 8 separate RAM chips. Is there any way to narrow down which chip (or chips) are causing the problem? I have 4 RAM chips and sockets ordered. I've read that sometimes piggybacking the chips with known working chips sometimes reveals the culprits, but sometimes it does not. Also, on the screen the is a parenthesis ")" or maybe "(" (I can't remember at the moment) about halfway down the screen. I vaguely remember reading somewhere that this could point to U10... is this right?

Please help.

I did not find the right solution from the Internet.

References:-
http://www.lemon64.com/forum/viewtopic.php?t=50949&sid=b56dc06f6ee0a969ad17e69a5b17fae4
[url=https://jobs.vidzzy.com/hire-corporate-video-animation-agency/]Corporate Video Animation Agency[/url]

Thanks!