ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi all,
I am trying to fix the sound adjustment functions on the panel, sadly without success so far.
Martin supplied the optical reader (FSH 900-2] and I was hopeful things would work again, but 🤬😢
Still no adjustment posible ! I can not reproduce the voltage range going to Pin 2 of IC2.
the 1.1VDC from R22 to Pin1 of the opto are present, , the voltage range coming from Pin 3 of the opto
are not.
the voltage signal going to Pin 57 IC1 should oscillate between 0- 4.75 VDC - it only varies between
about 3.4 - 4.7 VDC ???
the S1 micro switch looks like its working.
could it be possible the opto has been shot during the soldering process ??
I checked and replaced TR7 and IC2 .....no change.
can someone help please ?
thank you
ALf
Are you sure, it sits correctly and reads the black/white pattern correctly?Have you tried it outside the housing?
Martin
Absolutely sure - the two "open windows" of the part are the back of the reader, facing away from the black-white pattern.
i have not yet tried it outside the "wheel case" but will do.
my fear is I might have shot the reader during soldering ?!??
the rest of the MCP seems to function, turning sources on and off.
the 4.75 VDC seems to be omnipresent in that circuit ?
alf
Just tested the three pins of the reader when its outside the wheel cage:
I lost the 1.1VDC going/coming to Pin1, Pin2 as it was previously and Pin3 varies between 3.3-4.6 VDC, depending on direct light exposure or none.
ALF
Soldering that part at 400C temp will most likely have killed the optical reader.
according to its datasheet it should be soldered at about 230C DIP or 260C with heatsink 😢
wish I would have discovered that earlier ! 😢
yes, it did kill the reader 😢
but, good news a pair of new parts arrived - fitted a new one and the sound adjustment works again......although I still
would have loved to replace the micro-switch as the old one seems a tick touchy.....!!
if anyone can offer a good used replacement I would be very interested in buying.