SHARP SP1653 Technical Report

Date: Dec. 7, 1993

COPIER : SF-7850

1. REVOLVING CASSETE LOCK MALFUNCTION DUE TO
W-BASE PLATE LOCK SCRAPING.

2. ELIMINA TION OF IRREGULAR NOISE FROM THE DRUM UNIT.

No. : SP-1653

1. Revolving cassete lock malfunction due to w-base plate lock scraping.

1.Model name: SF-7850

2.General: As reported in T/R SP-1505, a holding claw reinforcement plate (CPLTM4403FC01)

had been added to the R-Base plate to alleviate the problem of wear on the holding
claws of the revolving drum lock. This reinforcement plate has caused scraping of the
W-base plate lock, causing the lock to malfunction and not work. A lock plate has
therefore been added to the W-base plate to alleviate the problem.

3.Reason: Revolving cassette lock malfunction due to scraping of the W-base plate lock.

4.Description: A lock plate has been added to the W-base plate cassette lock (right side only).

Added lock plate.

W-base plate.

SHARP CORPORATION Reprography Division

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Green

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Note: 1. When adding the lock plate, check to make sure that the cassette lock of the

W-base plate has been scraped and worn away as shown below.If it is not worn
down, it should be ground down (T/R SP-1507). Refer to diagram below.

2. It is necessary to remove the revolving cassette when installing the lock plate.

W-base plate.

★ The SF-7850 was located in the direction that the revolving cassette was pushed out

by the RM drive unit, but the holding claws of the cassette were scraped and lock
malfunctions occurred. In the case of the new SF-7855 / 7830, the cassette is pushed
out by only two springs that are located behind the cassette. Even if the claws are
scraped and worn down, it will not affect the power used to push out the cassette
enough to cause a lock malfunction. Therefore, the lock plate and reinforcement plate
have not been added to the SF-7855 / 7830 models.

5.Action (Factory action)
From 1993 November production.

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