HP Rp5700 - Point of Sale System Reference Manual page 190

U32
U46
U50
U51
U52
U53
XBT
XMM1
XMM2 - XMM5
XU1
XU2
XU15/U15
XU19/U19
Y1
Y2
Y3
Y4
Y5/H5
180 Appendix E System Board and Riser Board Reference Designators
Second serial port transceiver
VRM controller
USB front port power switch
First USB rear port power switch
Second USB rear port power switch
Third USB rear port power switch
Battery retainer
Memory slot. DIMM1 or RIMM1 populated and tested
Following memory slots
Primary processor socket
Secondary processor socket
System ROM and Socket (Socket = XU15, ROM = U15)
SPI ROM and socket (XU19 = socket, U19 = SPI ROM)
Primary (TH) system clock crystal
Secondary (SMT) system clock crystal
Primary NIC clock crystal
Secondary NIC clock crystal
RTC clock crystal/tie-down
ENWW