Any caps in the works that could have failed, or had their ESR rating
fluctuate? Not just electrolytics.
There are _lots_ of analog components in there. Was hoping
for a 'common cause' kind of idea. All fourteen op-amps
had what looked to be good outputs at least, so I'm not
expecting silicon
Any caps in the works that could have failed, or had their ESR rating
fluctuate? Not just electrolytics.
Any critical feedback resistors that could have drifted over time?
Did you throw the scope on the thing at various points along the signal
paths, checking each stage?
Conformal coat changing
The HVAC system in my '83 300D was doing weird things, even after
I replaced all the units, pushbutton, temp controller, and fan speed
controller units.
Having had bench experience with the weird things low voltage can cause
a solid state system to do; (especially "old" solid state systems), I use
I'll send you my box of spares if you want. If you can make 2 of them
work right send me one and we'll call it good. If you can only make
one work right keep it for yourself. If you can't make any work, add
them to the scrap pile.
Hey, I'll take that deal! We're headed out for a week's vacati
hem work
right send me one and we'll call it good. If you can only make one work right
keep it for yourself. If you can't make any work, add them to the scrap pile.
-Curt
Date: Thu, 4 Aug 2011 08:25:51 -0700
From: Jim Cathey
To: Mercedes Discussion List
Subject: [MBZ] 201 HVAC
Messag
Anybody have any in-depth experience with the early ('86) 201 HVAC
controller? Mine refuses to turn off the water valve so it's
always heating, and I've 100% proven that it is the HVAC box
that's not activating the vacuum solenoid, everything downstream
of there works perfectly if it's jumpered m
