HP 5850 - Deskjet Color Inkjet Printer Reference Manual page 239

U4 South bridge
U5 Super I/O
U6 Clock chip
U7 64 bit Bridge
U10 LOM1
U11 LOM1 EEPROM
U12 LOM1 PHY
U13 Audio Codec
U14 Audio amplifier
U16 LOM2
U17 LOM2 EEPROM
U18 LOM2 PHY
U19 SPI ROM - SOIC-8 footprint
U20 Fan controller
U21 SPI ROM - SO16 footprint
U29 TMDS controller
U30 Parallel port diode array
U31 First serial port transceiver
U32 Second serial port transceiver
U46 VRM controller
U50 USB front port power switch
U51 First USB rear port power switch
U52 Second USB rear port power switch
U53 Third USB rear port power switch
XBT Battery retainer
XMM1 Memory slot. DIMM1 or RIMM1 populated and tested
XMM2 - XMM5 Following memory slots
XU1 Primary processor socket
XU2 Secondary processor socket
XU15/U15 System ROM and Socket (Socket = XU15, ROM = U15)
XU19/U19 SPI ROM and socket (XU19 = socket, U19 = SPI ROM)
Y1 Primary (TH) system clock crystal
Y2 Secondary (SMT) system clock crystal
Y3 Primary NIC clock crystal
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