Specifications

Circuit Descriptions and Abbreviation List
GB 94 EM3E9.
9. Circuit Descriptions and Abbreviation List
Index of this chapter
1. Introduction
2. Block diagram
3. Power supply
4. Control
5. Tuner & IF
6. Video: High-end Input Processor
7. Video: Feature box
8. Video: High-end Output Processor
9. Synchronisation
10. Horizontal deflection
11. Vertical deflection
12. Audio
13. Teletext / NexTView
14. CRT / SCAVEM / Rotation
15. Software related features
16. Abbreviation list
9.1 Introduction
The EM3 Europe is a higher specified chassis as the EM2
Europe. EM stands for Eco-MG, 3 for an indication that this
set is higher specified as the EM2E. So EM2E is a known
chassis with Digital Scan, EM3E is set with Natural Motion,
EM4E will be the EM3E set inclusive a Digital Reception
board. -
Differences between the EM3E versus EM2E:
– the start-up method is much more simple (no POR-bit
anymore)
– the set has an advanced Standby Power Supply,
including MOSFET-switches for making Semi-standby
(needed for Easylink and digital reception in future)
– added features as Natural Motion, EPG, LTP and
upgraded Auto-TV
– the sound amplifiers have symmetrical supply voltages
now. The IC is changed from TDA2616 to TDA7490
(class-D amplifier, needing very little cooling)
– the vertical amplitude hardware alignment is changed to
a software alignment via the SAM menu
– the vertical shift alignment is split into a hardware
and a
software alignment (needed due to spread)
– the Frame drive signals from the HOP are symmetrical.
The architecture consist of a conventional large signal panel
(LSP) and a small signal board (SSB) module, placed into a
so called SIMM-connector (Standard Interface, 80 pins).
The LSP is built up very conventional, with hardly any surface
mounted components on the copper side. Similar with the
EM2E (but different as with the MG-chassis), the EM3E LSP
has a very large 'hot' part, including both deflection coils.
The SSB is a high tech module (2 sides reflow technology,
full SMC) with very high component density and complete
shielding for EMC-reasons. Despite this, it is designed in
such a way, that repair on component level still is possible.
To achieve this, attention was paid to:
• The position of service test lands: most of them are at the
Tuner side.
• Accessibility (Tuner side). If there are still problems with
the accessibility, one can order an extension board (see
parts list).
• Clearance around surface mounted ICs (for replacing).
• Detailed diagnostics and fault finding is possible via
ComPair.
Attention: During the first 4 to 6 months of production, the
EM3E set-software will be integrated into a Flash-RAM on
the SSB. After that period, a Mask-ROM will be used. Which
IC is used is not of interest for Service, however for both
solutions it means that Service Workshops must be equipped
with dedicated (de) solder equipment for exchanging these
ICs.
In case one must replace a Flash-RAM or a Mask-ROM in the
field, the Dealer will receive always an up-to-date Flash-
RAM.
Warning: Be aware that half of the LSP-circuitry is 'hot',
including the deflection coils.