Seller Note “Was working perfectly and then one day the fans would spin but would not display a signal.”
Summary
- Looks OK, quite cheap
- Resistances
- VCore – 0.2
- VMem – 27.7
- PEX – 44
- 1.8V – 4.4K
- 5V – 45K
- 3.3V – 38K
- 12V – 6M (slot), 6M (ext)
- Voltages – all present
- VCore – 0.74V
- VMem – 1.36
- PEX – 1.0V
- 1.8v, 5v, pex rst 3.3v, 3.3v, 12v
- Fan spinning quite fast, looks suspicious, concerned the core could be faulty…
- BIOS activity – none, with PEX RST present, this is not looking good
- pin 1 – no
- pin 2 – no
- pin 5 – no
This is the PEX reset circuit. This is the first time I’ve seen one without a logic gate, the 3.3V is present though.
Here is the BIOS chip, unfortunately, no signals detected with an oscilloscope.
