Seller Note “The card does not show up in Device Manager and the fans do not spin around all that happens is a white LED light comes on when the power cable is plugged in I have had this card from new and has never been worked on”
Summary
- Superb condition, box perfect, hope it can be fixed!
- Resistances
- vcore – 0.3
- vmem – 120
- PEX – 65
- 5v – 2K
- 1.8v – 850
- Voltages (all missing)
- Vcore – 0v
- Vmem – 0v
- PEX – 0.04v
- 3.3v – yes
- 1.8v – 0v
- 5v – 0v
- 12v – yes
- There is an ITE power management chip.
- Could do with a schematic, but at least there are actially very helpful labelled power rails on the back of the card.
With no minor voltage rails, the priority should be to understand why 5v is not present. The minor voltage rails fr 5v, 1.8v and PEX all seem to use these same buck converters:
AMCH 190 actually means AMC = NB671 (https://www.mouser.com/datasheet/2/277/NB671LB-1079585.pdf), the H 190 are just production-related digits.
This IC is very tiny and I was unable to probe its enable pin, but a nearby test point on the back reads 3.3v, which I suspect could be the enable voltage. VCC is showing about 5v which is expected. PGOOD is 0v, no surprise there. I would expect this buck converter needs replacing.
Voltage rails normally come up in this order:
5V→ 1.8V→ VCore→ VMem/PEX