* Insertion mechanism simplification. The floppy now rotate around the insertion slot toward the floppy drive mechanism. The external visual impact is a slimmer insertion slot.
* Index detection led uses a small PCB mounted on the loading mechanism.
* <span style="color:#FF0000">The write protection sensing is done using a [[Writepin|switch / pin assembly]].</span>
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The Test Points under the PCB are found near the front of the drive, near the drive LED.
On the 5 pin TP connector:
* pin 1 or pin 2 for head amplifier
* pin 3 is GND
* pin 4 is the index hole detection (high on index)
* pin 5 for track0 sensor (low when on track 0)
Reference: https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/eme-156-mechanics/msg172359/#msg172359
=== EME-156 V ===
* New head motor with a smaller diameter screw.
* Main PCB (Z80264) is 50% smaller than previous version. It cannot be fully removed without de-soldering some wires or un-mounting index sensor and track 0 sensor. Track 0 sensor has to be calibrated when mounted.
* <span style="color:#FF0000">The write protection sensing is done using a [[Writepin|switch / pin assembly]].</span>
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* Head and drive motors changed for 5V version.
* Main PCB (Z80425) slightly smaller than EME-156 V one. It cannot be fully removed without de-soldering some wires or un-mounting index sensor and track 0 sensor. Track 0 sensor has to be calibrated when mounted.
* White face to match Plus range coulorcolour.
* Minor modification of the brass chassis near the drive motor
* <span style="color:#FF0000">The write protection sensing is done using a [[Writepin|switch / pin assembly]].</span>
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== Drive maintenance ==
=== Rotation speed adjustment ===
3 inch drive spins at 300 RPM, giving a 200ms index pulse period. Rotation speed is factory adjusted, but may drift with time and cause read problem when drift is too large.
On EME 150A, the drive motor speed regulation is done on the main unit PCB, and is adjusted using VR201.
On Other model (155/156/156V/157), the drive motor includes its own regulation PCB, and adjustment is done on the motor itself, which can be one of the following reference (MMA-xxxxxx, QJN2-xxxx or MMU-xxxxxx)
<gallery>
File:EME-150A_RpmAdjust.jpg|EME-150 A speed adjust
File:EME-156_RpmAdjust.jpg|EME-156 A speed adjust
File:MMU-5B2LQJ_open.JPG|Detail of MMU-5B2LQJ motor speed regulator
</gallery>
Rotation speed can be checked either by monitoring the drive index pulse with an oscilloscope or by using dedicated SW like [http://www.cpcwiki.eu/forum/applications/dsktest-v0-1b/ DskTest] or [http://www.amstradtoday.com/resur/rpm.zip RPM].
Adjustment requires a 2mm wide screwdriver. A larger one will not fit in the potentiometer adjustment hole.
On MMA-xxxxxx, the adjustment hole is covered with a white rubber and the internal PCB is facing down. <span style="color:#FF0000">That requires additional precautions : forcing the screwdriver in the hole may detach the potentiometer from the PCB and damage the motor.</span>
On QJN2-xxxx and MMU-xxxxxx, the adjustment hole is covered with a black rubber and the internal PCB is facing up.
== Gallery ==
File:EME-156 Right.jpg|EME-156 Right side
File:EME-156 Left.jpg|EME-156 Left side
File:EME-156 Bottom.jpg|EME-156 BottomME56PB31 PCBFile:EME-156 Bottom ME56PB41.png|EME-156 Bottom ME56PB41 PCB
</gallery>
File:EME-157 Bottom.jpg|EME-157 Bottom
</gallery>
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