The COMPAL LA-4501P (KALA0) is a classic example of the AMD Puma/Griffin platform architecture found in the Acer Aspire 5536 and 5738G series. As a veteran engineer, I can attest that this board is a staple in the repair community due to its specific thermal characteristics and power management logic. Built around the AMD RS780M Northbridge and SB700 Southbridge, this motherboard requires a deep understanding of legacy rail sequencing and the common failures associated with the ENE KB926QF Super I/O controller.
Board Architecture & Technical Specifications
| Feature | Specification |
|---|---|
| Motherboard Model / ODM Part Number | COMPAL LA-4501P Rev: 1.0 (KALA0) |
| Target Laptop Series / Form Factor | Acer Aspire 5536 / 5536G / 5236 |
| Chipset / CPU Architecture | AMD RS780M + SB700 / Socket S1g3 (Athlon/Turion X2) |
| Super I/O (EC/KBC) Controller | ENE KB926QF D3 |
| Key Voltage Rails & Switching Coils | PL4 (+3VALW), PL5 (+5VALW), PL8 (+1.1V_HT), PL10 (+VCC_CORE) |
Real-World Motherboard Diagnostic Procedures
1) DC-IN Protection & ISL6251 Charging Logic
On the LA-4501P, the +19VB rail is managed by the ISL6251 (PU1) charging IC. If you have no power and no LEDs, first check for 19V at the drain of PQ1 and PQ2 (SI4407 P-Channel MOSFETs). A common failure point is the gate drive signal PACIN. If PACIN is low, the main MOSFETs won't open. Ensure PR3 (current sense resistor) isn't open and that the ACIN signal (pin 2 of PU1) is approximately 3.2V. If the battery is detected but won't charge, inspect PQ11 and PQ12 for high-side switching shorts.
2) Standby Rail Generation (+3VALW / +5VALW)
The standby voltages are generated by PU4 (TPS51125). This IC must output +3VLP (LDO) on pin 8 to power the EC (KB926QF) before the main switching rails +3VALW (PL4) and +5VALW (PL5) are enabled. If these rails are missing, measure the resistance to ground on PL4 and PL5. Normal readings should be in the K-ohm range. If PL4 is shorted, the Southbridge (SB700) or the EC itself is the primary suspect. Check the ENTRIP1 and ENTRIP2 signals; if the EC does not pull these high, the buck converter will remain dormant.
3) AMD Platform Power-On Sequence & RS780M Failure
This board often suffers from "No Display" despite fans spinning. This is frequently due to the RS780M Northbridge failing under thermal stress. Before reflowing or replacing the BGA, track the power sequence: EC_ON triggers the secondary rails, followed by SYSON and SUSP#. Verify that RSMRST# (pin 100 of KB926) goes high (3.3V) when the power button is pressed. If +VCC_CORE on PL10 is present but there is no POST, check the 32.768kHz crystal (Y3) near the Southbridge. If the clock is stable, a corrupted BIOS dump on U17 (SST25VF016B) is a likely culprit before condemning the Northbridge.
Download Schematic & Boardview Files
Direct download link. Verified schematic / boardview archive for Acer Aspire 5536/5738G.
Professional Repair Assistance
Explore our technician resources:
- 🛠️ Diagnose No-Power & Short-Circuit faults step-by-step: Interactive Laptop Diagnostic Lab
- 🛒 Original Replacement Motherboards & IC Components: Official Spare Parts Mega Store
