N900 Hardware Schematic

An N900 schematic appears to be at [1] and now on [2]. Service Manuals L1_2 and L3_4 can be found under e.g. http://www.google.de/search?q=Nokia_N900_RX-51_Service_Manual_L1L2_v1_0.pdf

This might not be the exact version of the schematic used to make the phone.

Revision is given as 2JH_21A on the schematic. However, the pictured PCB in the schematic is 2JH_20 - see above the third row from the right keys. A dissasembled purchased n900 showed a revision number of 2JH_21[1].

This is a brief list of what's where on the schematic. It generally only includes major components, and any minor components that have a direct bearing on software.

Contents

[edit] Page 1 Front page

Frontpage with photo and index, version index, (C) mambojambo

[edit] Page 2 CPU, Camera, Accelerometer

[edit] Page 3 Memory

  • N5210 - uSD hotswap detector (a Hall switch or Reed, operated by magnet in back cover)
  • D4800 - OMAP3430 - N900 CPU
  • D5000 - Combo memory - 64M*32 DDR, 128M*16 Flash. (POP Package On Package on top of OMAP)
  • D5200 - eMMC 32 GB

[edit] Page 4 GAIA

  • Gaia - TWL4030 - N900 Hardware Chipset
  • N4290 - 2.5 V regulator with enable.
  • G4246 - 19.2 MHz TXCO
  • N4242 - 2.8 V regulator with enable.
  • M4270 - Vibrator motor
  • D4280 - USB PHY - N900 Hardware USB
  • N1130 - Fuel Gauge - N900 Hardware Charge Meter
  • N1140 - Battery Charger - N900 Hardware Battery Charger
  • R1129+R1130 - Sense resistor for Fuel Gauge. (actual values in milli Ohms *urgently* needed! Seems to be 20mR)
  • R1110 - 10 K thermistor in parallel with 1n to ground, to ADCIN0 on GAIA - labeled "Battery temperature sensor"

[edit] Page 5 Display

Erratum: 

I2C_2(1:0)
CPU > OMAP3430

is I2C_3, not I2C_2

[edit] Page 6 LEDs

  • N1322 - R&D mode LED driver.
  • N1301 - LED driver - keyboard, notification - N900 Hardware LED

[edit] Page 7 Keyboard

  • S4311/2 - Volume keys
  • S4313 - Lock switch
  • S4301 - Power button
  • S4314 - Capture key (two level)
  • QWERTY keyboard

[edit] Page 8 Audio, FMTX

[edit] Page 9 BTFM, WLAN

  • N6543 - 2.8 V regulator with enable, provides power to:
  • G6450 - 38.4 MHz VCTCXO - clock for Bluetooth and WLAN modules automatically enabled when either require clock, through D6450 OR gate to above regulator.
  • N6300 - WLAN module
  • N6000 - BT module / FM receiver - N900 FM radio receiver

Erratum: 

WLAN_BT(3:0)

line_3 N6300 WLAN module : BT_FREQ goes to nirvana

[edit] Page 10 GPS

  • N6200 - GPS module
  • G6200 - GPS clock - 16.368 MHz

[edit] Page 11 RAPUYAMA, GAZOO

  • N2200 - Gazoo (modem companion chip similar to GAIA)
  • D2800 - Rapuyama - Nokia BB5 Modem
  • D3000 - 128 Mbit NOR flash + 128 Mbit DDR RAM - connected only to Rapuyama

[edit] Page 12 Display flex connector

  • N1540 - Reflective optical switch (proximity sensor)
  • N1530 - Ambient light sensor
  • N1550 - CMOS camera module
  • V1540 - RGB indicator LED

Erratum: 

I2C_3(1:0)
BTFM > BTFM Module
CPU > OMAP3430

Offsheet symbol incorrect, connection to I2C_3 is via BTB(12:13). Probably, when fixing erratum on page 5, this off sheet symbol is no longer needed to make DRC happy.

[edit] Page 13 RF Part

Cellphone components RF block
  • N7560 - Aura DC/DC converter for power supply
  • N7500 - Vapaus RX I/Q sampling, TX encoder, connected to RAPUYAMA. Provides reference clock to GPS
  • N7540 - WCDMA Power amplifier TX

[edit] Page 14 Signal Overview (Top)

Full size photo front view of PCB. (higher resolution scans to be found here[1])

Wlan nominal spectrums, various clock nominal levels.

[edit] Page 15 Signal Overview (Bottom)

Full size photo rear view of PCB.(higher resolution scans to be found here[1])

More clock levels, nominal GSM and CDMA spectrum.

[edit] Page 16 Component Finder (Top)

Component placement front side

[edit] Page 17 Component Finder (Bottom)

Component placement rear side

[edit] Page 18 Component Finder-Display flex

Display Flex Connector component placement

[edit] Note on component types and values

The schematics only use symbolic labels for most components, and abstract names made up by Nokia for some of the large chips (e.g. GAYA, RAPUYAMA). However at least most resistors and capacitors have their size printed next to them. So the simpler the component, the harder it gets to tell what it actually is - except for capacitors and resistors. For a lot of chips you can read the actual printing from body of component, by looking at the photos p. 14, 15 and at Joerg Reisenweber's highres scans [1].

This webpage[2] has a pretty decent list of components from a reverse engineering teardown effort by isuppli.com. Almost a BOM, if only they had added the symbolic labels or exact component locations to link back to the schematics. Comes even with links to datasheets, physical dimensions of component, etc pp.

[edit] References

  1. ↑ 1.0 1.1 1.2 1.3 http://maemo.cloud-7.de/Gallery-N900-exploded/
  2. ↑ http://www2.electronicproducts.com/Nokia_N900_Mobile_Phone-whatsinside_text-90.aspx
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