Dell P80G, Service Manual

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Curved edge
DDR4 modules feature a curved edge to help with insertion and alleviate stress on the PCB during memory installation.
Figure 3. Curved edge
Memory Errors
Memory errors on the system display the new ON-FLASH-FLASH or ON-FLASH-ON failure code. If all memory fails, the LCD does not
turn on. Troubleshoot for possible memory failure by trying known good memory modules in the memory connectors on the bottom of the
system or under the keyboard, as in some portable systems.
NOTE: The DDR4 memory is imbedded in board and not a replaceable DIMM as shown and referred.
USB Type-C
USB Type-C is a new, tiny physical connector. The connector itself can support various exciting new USB standards like USB 3.1 and USB
power delivery (USB PD).
Alternate Mode
USB Type-C is a new connector standard that is very small. It is about a third the size of an old USB Type-A plug. This is a single
connector standard that every device should be able to use. USB Type-C ports can support a variety of different protocols using
“alternate modes,” which allows you to have adapters that can output HDMI, VGA, DisplayPort, or other types of connections from that
single USB port
USB Power Delivery
The USB PD specification is also closely intertwined with USB Type-C. Currently, smartphones, tablets, and other mobile devices often
use a USB connection to charge. A USB 2.0 connection provides up to 2.5 watts of power — that'll charge your phone, but that's about
it. A laptop might require up to 60 watts, for example. The USB Power Delivery specification ups this power delivery to 100 watts. It's bi-
directional, so a device can either send or receive power. And this power can be transferred at the same time the device is transmitting
data across the connection.
This could spell the end of all those proprietary laptop charging cables, with everything charging via a standard USB connection. You could
charge your laptop from one of those portable battery packs you charge your smartphones and other portable devices from today. You
could plug your laptop into an external display connected to a power cable, and that external display would charge your laptop as you used
it as an external display — all via the one little USB Type-C connection. To use this, the device and the cable have to support USB Power
Delivery. Just having a USB Type-C connection doesn't necessarily mean they do.
USB Type-C and USB 3.1
USB 3.1 is a new USB standard. USB 3's theoretical bandwidth is 5 Gbps, while USB 3.1's is 10 Gbps. That's double the bandwidth, as fast
as a first-generation Thunderbolt connector. USB Type-C isn't the same thing as USB 3.1. USB Type-C is just a connector shape, and the
underlying technology could just be USB 2 or USB 3.0. In fact, Nokia's N1 Android tablet uses a USB Type-C connector, but underneath
it's all USB 2.0 — not even USB 3.0. However, these technologies are closely related.
Technology and components 11