Operating instructions

6. Working from left to right, repeat steps 3,4, and 5 for each additional
metallic part in the tape path:
A. Tachometer idler G. Tape lifter (right)
B. Guide roller (Supply) H. Reproduce head
C. Tape lifter (left) I. Guide roller (Take-up)
D. Erase head J. Capstan idler
E. Record head K. Take-up swing arm roller
F. Scrape flutter filter roller
7. When all the above parts have been demagnetized, draw the
demagnetizer at least 1 meter (3 feet) away, turn it off and/or unplug it.
5.1.2 Cleaning the Tape Path
It is important to regularly clean the route along which the tape travels.
Oxide and dirt will shed from the tape and accumulate on the following parts
causing a build-up that can create slippage, degrade frequency response and
accelerate tape wear.
CAUTION: Never use any metallic item or abrasive to clean the heads or
other tape guidance items. Never use MEK, spirits, lacquer thinner, acetone,
or other solvents on the tape heads. Rubbing alcohol should be avoided
since it contains oil that will leave a residue.
1. Moisten a cotton swab with pure (97–99%) isopropyl alcohol and wipe
the entire surface of the Supply swing arm roller. Also clean the upper
and lower flanges of the swing arm to keep oxide out of the roller reliefs
(upper and lower cuts in the roller). Allow the roller to dry by
evaporation.
2. Moisten additional swabs and clean the following parts:
A. Guide roller (Supply) F. Tape lifter (right)
B. Tape lifter (left) G. Reproduce head
C. Erase head H. Guide roller (Take-up)
D. Record head I. Take-up swing arm roller
E. Scrape flutter filter roller
CAUTION: Do not use isopropyl alcohol for the tachometer and capstan
rollers. Instead used Otari “Deck Solvent” or equivalent that has similar high
volatility.
This should be done as often as humanly possible, i.e., between sessions or
approximately every 2–4 reels of tape.
MTR-90III Operation and Maintenance Manual
September 1996
Section 5 Maintenance
5 - 3