Reading through this again, FixItFelix hit the nail on the head with the hidden HDD BIOS partition theory. Compaq’s implementation of what was essentially a Phoenix BIOS stored in a protected area of the drive (often the first few tracks, outside the normal partition table) was a notorious single point of failure. The fact that the DVD drive kept blinking with no disc is the classic symptom of a system that has lost its boot vector entirely — the BIOS firmware in the SPI flash would still be intact enough to initialize the SATA/IDE controller, but without a valid master boot record or BIOS extension loaded from the HDD’s hidden sector, it cycles through possible boot devices and hangs.
One thing I’d add: this specific failure mode (first boot works, then dead after a forced shutdown) strongly suggests a write failure during initial setup. Windows XP setup writes to the boot sector and the BIOS partition concurrently. If the HDD had a weak sector in that region — maybe from a head slap during shipping — the write would succeed partially, but the next read would fail, corrupting the reference the BIOS needs to pass control to the OS. A head crash or a bad sector in that precise location would leave the BIOS looking for a valid signature that no longer exists.
Modern diagnostic techniques, like attaching a POST card to the mini-PCI or LPC bus, would show you exactly where the boot process halts. But for vintage Compaqs, I’d follow this sequence:
- Remove the hard drive entirely.
- Pull the CMOS battery, hold power button for 60 seconds, then replace only one known-good RAM stick.
- Try booting from a known-good Windows XP CD (not the recovery disc, just a retail disc).
- If still no POST, test the power rails with a multimeter — a failed capacitor on the voltage regulator module can cause the CPU to never receive its core voltage, which matches the “no beeps” symptom.
The blinking DVD drive is a red herring; it’s just the default fallback behavior. The real failure is most likely a corrupted BIOS partition on the HDD or a marginal component that died under thermal stress during first boot.
One more nuance: Compaq’s “system restore” function required a pre-set key combination (like F10 or Ctrl+F10) during POST, but POST never initialized, so that path was dead too. The lack of any audible error codes (no beeps at all) points to a failure before the POST handler even runs — the CPU or chipset never signalled the speaker driver. I’ve seen similar on other laptops where a bulged capacitor on the output side of the DC-DC converter robbed the CPU of its 1.3V rail. That would explain the “works once, then never again” pattern: the cap was marginal, heated up during first boot, expanded, and failed short, killing the rail permanently.
So if I had to put money on it, my guess is a combination of a marginal capacitor on the motherboard (most likely a 6.3V 1500µF near the CPU socket) and a coincidental weak sector on the HDD’s BIOS partition. The first boot worked because both were barely alive; the forced shutdown stressed the capacitor past its limit, while the setup write nuked the BIOS signature. Double whammy.
Below is a quick diagnostic flowchart summarizing the recommended isolation steps:
flowchart TD
A[Compaq Presario: No POST, blinking DVD drive] --> B{Remove HDD and try to boot from CD/USB}
B -->|Still no POST| C{Reseat RAM, one stick, known-good}
C -->|Still no POST| D{Clear CMOS: battery removal + power drain}
D -->|Still no POST| E{Check motherboard voltages with multimeter}
E -->|CPU Vcore missing| F[Replace failed capacitor on VRM]
E -->|All rails present| G[Likely dead chipset or CPU - replace motherboard]
B -->|Now POSTs| H[Corrupted BIOS partition on original HDD]
H --> I[Replace HDD, restore BIOS via vendor disk if possible]
That covers the most likely scenarios. The lack of beeps really narrows it down to either a power delivery issue or a completely dead CPU/chipset, and given the thermal history, I’d inspect that VRM area first with a bright flashlight. Good discussion — brings back memories of salvaging these machines from the e-waste pile.
