• Depending on the version of operating systems, some user interface instructions might not be applicable to your computer. • Documentation content is subject to change without notice. Lenovo makes constant improvements on the documentation of your computer, including this Hardware Maintenance Manual. To get the latest documentation, go to https://support.lenovo.com...
This guide addresses only those items. You should use good judgment to identify potential safety hazards due to attachment of non-Lenovo features or options not covered by this inspection guide.
4. Check for cracked or bulging batteries. 5. Remove the cover. 6. Check for any obvious non-Lenovo alterations. Use good judgment as to the safety of any non-Lenovo alterations. 7. Check inside the unit for any obvious unsafe conditions, such as metal filings, contamination, water or other liquids, or signs of fire or smoke damage.
The safety notices in this section are provided in the following languages: • English • Arabic • Brazilian Portuguese • French • German • Hebrew • Japanese • Korean • Spanish • Traditional Chinese DANGER DANGER DANGER Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
• If the voltage is acceptable, do the following: a. Replace the system board. b. If the problem persists, call the Customer Support Center. Note: Noise from the ac power adapter does not always indicate a defect. Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Step 2. Download the image file of the repair shim from http://www.lenovo.com/support . A Lenovo service credential is needed to download the image file. Attention: Make sure to download the latest version of the image file. A shim created with an earlier version of the image file may cause the repair process to fail.
GoogleRequiredTests GoogleRequiredTests checks the system status and helps reset the system back to the factory-default settings. If any tests fails, the system cannot be finalized. Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Page 33
Common issues leading to GoogleRequiredTests fail Issue Description HWID mismatch Each Chromebook has a known hardware configuration. Each configuration is assigned an HWID. HWID mismatch can be caused by using unauthorized parts, or missing parts. If the write-protect function is not turned off before recovering the computer with the repair shim, it will also cause HWID mismatch.
Lenovo will ship the CRU to you. CRU information and replacement instructions are shipped with your product and are available from Lenovo at any time upon request. You can find a list of CRUs for your product in this Hardware Maintenance Manual. An electronic version of this manual can be found at .
Major FRUs and CRUs Figure 1. Lenovo Chromebook S345-14AST exploded view Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Page 37
Note: Depending on the computer model, your computer might look different from the illustration above. Table 3. Major FRUs and CRUs FRU description Optional-service CRU Self-service CRU LCD module Upper case (with keyboard) Antennas (main + auxiliary) Touchpad assembly System board Speakers Wi-Fi card I/O board and I/O board cables...
• Screw M2.5 x 5.0, silver (4) Two acetate fabric tapes (for speakers) Conductive tape (for touchpad) Looking up the FRU information For detailed FRU information, including part numbers, descriptions, and substitution part numbers, go to: https://support.lenovo.com/partslookup Chapter 4 Identifying FRUs (CRUs)
6. When replacing a FRU, carefully retain and reuse all screws. If screws are missing, look up details in “Miscellaneous parts” on page 33 for replacement screws and order them through the Lenovo CRM system. 7. When replacing the base cover, reapply all labels that come with the replacement base cover. If some original labels are not included with the replacement base cover, peal them off from the original base cover and paste them on the replacement base cover.
M2.0 x 4.0 Black M2.0 x 6.0 Black M2.0 x 8.0 Black Step 2. Insert a pry tool to separate the lower case from upper case. Figure 4. Separate the lower case from upper case Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Step 3. Remove the lower case. Figure 5. Remove the lower case Refer to “Major FRUs and CRUs” on page 30 to look up details about the following replacement part: Lower case Remove the battery pack Make sure the following FRU (or CRU) has been removed. “Remove the lower case”...
Refer to “Major FRUs and CRUs” on page 30 to look up details about the following replacement part: Battery pack Remove the Wi-Fi card Make sure the following FRUs (or CRUs) have been removed. “Remove the lower case” on page 36 “Remove the battery pack” on page 37 Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Page 45
Step 1. Detach the main and auxiliary antenna connectors. Figure 9. Detach the 2 connectors Step 2. Remove 1 screw. Figure 10. Remove 1 screw Screw specifications Number of screws Color M2.0 x 2.5 Black Chapter 5 Removing a FRU or CRU...
“Remove the lower case” on page 36 “Remove the battery pack” on page 37 Step 1. Detach the two I/O board connectors from the system board. Figure 12. Detach the two I/O board connectors Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Page 47
Step 2. Remove the screws. Figure 13. Remove the screws Position Number of screws Screw specifications Color M2.5 x 5.0 Hinge (right) Silver M2.0 x 5.0 I/O bracket (right) Silver M2.0 x 3.0 I/O board Black Step 3. Remove the right I/O bracket. Figure 14.
Refer to “Major FRUs and CRUs” on page 30 to look up details about the following replacement parts: I/O bracket (right) I/O board Remove the speakers Make sure the following FRUs (CRUs) have been removed. “Remove the lower case” on page 36 “Remove the battery pack” on page 37 Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Page 49
Step 1. Detach the speaker connector from the system board. Figure 17. Detach the speaker connector Step 2. Peel off two acetate fabric tapes. Figure 18. Peel off the acetate fabric tapes Step 3. Fold the keyboard cable upwards to release the speaker cables. Figure 19.
“Remove the Wi-Fi card” on page 38 Step 1. Detach the 6 connectors from the system board as follows: • two I/O board connectors • EDP cable connector • speaker connector • keyboard connector • touchpad connector Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Page 51
Figure 21. Detach the 6 connectors Step 2. Remove the screws. Figure 22. Remove the screws Screw specifications Position Number of screws Color M2.5 x 5.0 Hinge (left) Silver M2.0 x 5.0 I/O bracket (left) Silver M2.0 x 3.0 Black System board Chapter 5 Removing a FRU or CRU...
Page 52
Figure 24. Open the left hinge Step 5. Carefully remove the system board. Figure 25. Remove the system board Refer to “Major FRUs and CRUs” on page 30 to look up details about the following replacement part: System board Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
I/O bracket (left) Remove the upper case (with keyboard) Make sure the following FRUs (CRUs) have been removed. “Remove the lower case” on page 36 “Remove the battery pack” on page 37 Step 1. Detach the EDP cable connector from the system board. Figure 26.
Make sure the following FRUs (or CRUs) have been removed: “Remove the lower case” on page 36 “Remove the battery pack” on page 37 Step 1. Detach the touchpad connector from the system board. Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Page 55
Figure 30. Detach the touchpad connector Step 2. Fold the keyboard cable upwards. Figure 31. Fold the keyboard cable upwards Step 3. Peel off the conductive tape. Figure 32. Peel off the conductive tape Step 4. Remove the 5 screws. Chapter 5 Removing a FRU or CRU...
Page 56
Color M2.0 x 2.0 Touchpad Silver M2.0 x 2.0 Touchpad bracket Silver Step 5. Remove the touchpad bracket. Figure 34. Remove the touchpad bracket Step 6. Remove the touchpad. Figure 35. Remove the touchpad Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Refer to “Major FRUs and CRUs” on page 30 to look up details about the following replacement part: touchpad assembly conductive tape Disassemble the LCD module The LCD module as a whole is not a FRU. Instead, it contains FRUs as its components. Before disassembling the LCD module, make sure it has been detached from the upper case.
Page 58
Remove two hinge covers on the left and right. Figure 37. Remove the hinge covers Step 3. Remove the 6 screws. Figure 38. Remove the 6 screws Screw specifications Number of screws Color M2.5 x 2.2 Black Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Page 59
Step 4. Remove the left and right hinges. Figure 39. Remove the hinges Step 5. Pull out two removable tapes on the left and right. Figure 40. Pull out two removable tapes Step 6. Carefully lift the LCD panel, detach the EDP cable connector from the panel, and then remove the LCD panel.
“Remove the lower case” on page 36 “Remove the battery pack” on page 37 “Remove the upper case (with keyboard)” on page 47 “Remove the LCD panel” on page 51 Step 1. Detach the camera connector. Lenovo Chromebook S345-14AST Hardware Maintenance Manual...
Page 61
Figure 42. Detach the camera connector Step 2. Release the EDP cable. Then, remove the EDP cable and camera board. Figure 43. Remove the EDP cable and camera board CAUTION: The camera board is fragile and easily bent. Remove it with great care. Refer to “LCD FRUs and CRUs”...
Appendix A. Features and connectors 1 2 3 Figure 44. Lenovo Chromebook S345-14AST features and connectors Table 6. Features and connectors Feature or connector Camera light Camera Microphones dc-in / USB-C connector dc-in light USB 3.0 (Type-A) connector Combo audio connector...