Quite so ..
Although I did not say do not take it apart I quite agree.
Heads would always be replaced never repaired.
I do remember a field service engineer gently moving the print wires with a
pair of needle nosed pliers where they were visible underneath. I was
surprised how far they stuck out in front of the final guide.
Regards
?
Rod Smallwood
?
?
-----Original Message-----
From: cctech-bounces at
classiccmp.org [mailto:cctech-bounces at
classiccmp.org]
On Behalf Of Tony Duell
Sent: 12 September 2012 20:29
To: cctalk at
classiccmp.org
Subject: Re: Selenar Graphics II (Was: DECWriter II LA36 being given away)
Some things to watch for on the LA36
1. If you get a light or missing dot do not assume it's one of the print
head solenoids or a driver transistor. The synthetic agate through which
the
wires run to the print point were prone to get gummed
up. Take the head
off
and wash it in alcohol. Look out for the agate falling
out when you wash
it.
Do not dismantle th printhead (The same applies to the LA100 head, and
many Epson heads, and doubtless others). Dismantling it is easy.
Reassembling it is next to impossible. The print pins (wires) were
originally mcuh longer, they were fed through the guides, the head was
put toghter, the wirees were then cut/groudn to length. if you take the
head apart, you will never get the wries to stay through all the guides
(due to the return springs) whill you puti together. Oh, the wires are
some metal that is quite brittle and which will not take solder. Don't
ask...
The only heads I would attemtp to dismantle i nthe field and there ones
in the Sanders variopritners, the Model 43 Teletype one (for which there
is a dismantling procedure given i nthe service manual) and the old Epson
ones (TX80, also used in Commoder 2022, etc) where the front section
cotnaing the print pins is a complete unit that comes off with a retainer
plate to keep the wires in position. Don;t dismantle that but you can
take the solenoid section apart.
-tony