Seller Note “This card is FAULTY. When tested the fans spin as normal however there is no display output to the monitor. There is slight damage to the power port on the back.”
- Blank screen, some warmth on GPU.
- Not detected as secondary card.
- Main resistances and voltages seem to be present.
- Guess there is a chance the GPU itself is dead, but this should be proved.
- Actually, there appears to be damage to a logic chip near the PCI that is involved with the PCI reset signal (RST_EN). this could explain the card not waking up (fingers crossed GPU could be OK!).
Pre Checks / Multimeter Only
|Test / Checks||Result||Notes|
|1. Visual Inspection Eye / Magnifying Glass||Superficially, like-new condition|
|2. Visual Inspection Microscope||–|
|3. Check for shorts on 12v PCI, 12v PCI-E, 3.3v||OK||Couldn’t find any obvious shorts.|
|4a. Resistance VCore (~0.5)||7.2Ω|
|4b. Resistance VMem (~60Ω)||198Ω|
|4c. Resistance 3.3v Rail (~960Ω+)||Ω|
|4d. Resistance 5v Rail (~5KΩ)|
|4e. Resistance 1v PEX Rail (~123Ω+)||291Ω|
|4f. Resistance 12v BUS (14.7kΩ )|
Power On / Test Rig Checks
|Tests / Checks||Result||Notes|
|1. Observations (e.g. PCB heat noticed, |
blank screen, power light on monitor,
bios screen, o/s loaded, artefacts, )
little heat (GPU), some warmth around the back of VRM area.
|Hard to probe with a heatsink, hopefully, safe to investigate with a small passive heatsink. There are voltages, GPU gets hot over time (>5 mins)|
|2. Voltage VCore (~0.88v)||0.9v||OK|
|3. Voltage VMem (~1.4v)||1.52v|
|4. Voltage PEX Rail (~1v)||0.99v|
|5. Voltage 3.3 BUS||–|
|6. Voltage 12 Ext||–|
|7. Voltage 5v Rail||–|
|8. Voltage VDDCI||1.08v||Not sure what is normal for this type of card, but doesn’t look too high.|
|9. Voltage 1.8v||–||U300|
GPU: Antigua PRO (215-0877000) This is available, but quite expensive (Aliexpress £45)
Chip u501 Main PWM Controller (labelled PU100 on this board)
BIOS U11 (25Q21BT)
Update – Damaged Noticed
Under a microscope I noticed damage to a chip that could explain why the card has voltages, but wont wake up:
This logic chip is responsible for deciding whether the PCI express reset signal is received:
I think the chip is actually one like thes 74LVC1G08GW SOT353 (https://www.farnell.com/datasheets/1645571.pdf) Logical AND gate.