The 2-ohm current sense resistors (PR101, PR102). In Rev 1.0 boards, they were 0805 size. In Rev 2.0 boards, they are 1206. If your ILPI354 gets hot but you have 19V on pin 17, replace these resistors even if they measure fine. They develop micro-cracks. Use 1.5-ohm to 2.2-ohm as a modern substitute.
Before you probe with a multimeter, you must understand the board’s architecture. The updated schematic divides the board into four distinct zones:
If you search the internet, you will find dozens of low-resolution, often incorrect schematics for the ILPI354 VA. The original diagrams (Version 1.0 and 1.1) contained critical errors, particularly regarding the feedback loop for the standby voltage (3.5V or 5V) and the pinout of the main transformer (T101).
The updated schematic (Version 2.2+) corrects the following:
The ILPI354 schematic hasn't been "updated" by HP. It has been updated by the repair community reverse-engineering board revisions. The schematic you need is a TPS51125 application circuit combined with the LA-3541P Rev 2.0 boardview. ilpi354 va schematic updated
Bookmark this: 19V in → 3.3V linear → 5V linear → 3.3V/5V PWM out. If that chain breaks, the ILPI354 (or its support resistors) is the culprit.
Have you repaired an ILPI354 board lately? Drop the board model in the comments—I’ve likely fixed it.
Disclaimer: Always use an ESD mat and a current-limited power supply (1A max) when probing these circuits.
Blog Title: ILPI354 VA Schematic Updated: What’s New and Why It Matters for Repairs The 2-ohm current sense resistors (PR101, PR102)
URL Slug: /ilpi354-va-schematic-updated
Reading Time: 4 minutes
If you repair monitors, all-in-one PCs, or BenQ/LG displays, you’ve likely crossed paths with the ILPI354 VA power/LED driver board. Good news for the repair community: a major update to the schematic diagram has just been released.
Here is everything you need to know about the updated ILPI354 VA schematic, what errors were fixed, and how to use it for accurate troubleshooting. Disclaimer: Always use an ESD mat and a
The updated schematic is available immediately. You can access the files below:
The schematic shows a split-rail design:
| Pin | Name | What you should see (Updated notes) | Common Failure | | :--- | :--- | :--- | :--- | | 1 | EN0 | 3.3V (from VIN divider) | 0V = Bad resistors (R319/R320) | | 3 | VREG3 | 3.3V linear out | Short to GND (replace IC) | | 4 | VREG5 | 5V linear out | 2V-4V = Blown cap on 5V rail | | 6 | VO1_ON | 3.3V enable for 5V PWM | Check R326 pull-up | | 17 | VIN | 19V (via 2-ohm resistor) | Open resistor (look for burnt) | | 18 | EN1 | 3.3V (S5 enable) | 0V = S5 state stuck | | 23 | TRIP1 | OCL (Overcurrent latch) | 0V = Replace IC |
For those new to the project, the ILPi354 is [insert a 1-sentence description of the project, e.g., a high-fidelity audio amplifier module / a precision control board]. At the heart of this design lies the Voltage Amplifier (VA) stage, which is critical for [mention function, e.g., signal integrity / gain structure].