another thing to consider: when i did my CMOS job, i used the decoupled sockets. they
are $3 a pop, but the prospect of my potentially botching any of the cap placements
seemed pretty high(i hate jamming 2 legs in one pad hole). IMO, i'd consider redoing the sockets with the readymade ones.
also, in the interest of preserving your highly valuable synth, if you see yourself doing
a lot of desoldering, id invest in a hakko desoldering iron. i use it ALL the time; it preserves traces like you wouldnt believe! amazing piece of machinery. good luck-rj
--- On Mon, 1/19/09, Stephen Jones <thirteentech@...> wrote:
From: Stephen Jones <thirteentech@...>
Subject: Re: [yamahacs80] Re: Replacing all CMOS 4000 Series Logic IC's
To: yamahacs80@yahoogroups.com
Date: Monday, January 19, 2009, 9:47 PM
I agree with Kent, I have done the CMOS/decoupling cap job before with no problems. The circuits in the CS-80 are not critical enough to be worrying about switching speeds. Look for broken wires, bridges, cracked tracks, and if you find nothing then look for a fault unrelated to the re-chip, because sometimes coincidences do happen. Also, if you are doing things like measuring the resistance of CMOS switches, remember that the chips do not like having voltages applied to their pins if the chip itself is unpowered.
____________ _________ _________ __
From: mborish_2000 <mborish_2000@ yahoo.com>
To: yamahacs80@yahoogro ups.com
Sent: Tuesday, January 20, 2009 12:19:54 PM
Subject: [yamahacs80] Re: Replacing all CMOS 4000 Series Logic IC's
It might. Some of the older chips took forever to switch. I haven't
seen a datasheet for the original 4000 series Toshiba IC's. I'm going
to do that next. The new 4000 series chips have much lower internal
resistances.
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