Dataland R9 370 2Gb

Seller Note “Was working fine until I turned the PC on one day and there was no power going to it.”

Summary

  • Visually seems ok, couldn’t see any missing components. A bit dirty in places.
  • Check fuse F1800, F400 (top left) – Both seem fine.
  • Resistances seems OK. Main voltages present, but missing Vcore and Vmem at least.
  • Need to deep dive on buck converters etc to try and understand power rail logic (no boardview available)
  • Don’t think COMP is high enough on the Vmem drivers U701 & U801 – Need to understand more
  • Need to check U601 PWM for Vcore

Pre Checks / Multimeter Only

Test / ChecksResultNotes
1. Visual Inspection Eye / Magnifying GlassA bit dirty in places. Nothing obviously missing.
2. Visual Inspection MicroscopeFound two fuses, think both are OK.
3. Check for shorts on 12v PCI, 12v PCI-E, 3.3vOKCouldn’t find any obvious shorts.
4a. Resistance VCore (~0.5)4.6Ω
4b. Resistance VMem (~60Ω)40Ω+
4c. Resistance 3.3v Rail (~960Ω+) 420Ω
4d. Resistance 5v Rail (~5KΩ)1.7KΩ
4e. Resistance 1v PEX Rail (~123Ω+)88.5Ω
4f. Resistance 12v BUS (14.7kΩ )1.8KΩ
4g. VDDCI40Ω+

Power On / Test Rig Checks

Tests / ChecksResultNotes
1. Observations (e.g. PCB heat noticed,
blank screen, power light on monitor,
bios screen, o/s loaded, artefacts, )
Few voltages.
No picture.
No heat (GPU).
2. Voltage VCore (~0.88v)0vMissing
3. Voltage VMem (~1.4v)0vMissing
4. Voltage PEX Rail (~1v)1.0vL900
5. Voltage 3.3 BUS3.3v (F1800)
6. Voltage 12 Ext12v
7. Voltage 5v Rail5v (F400)
8. Voltage VDDCI0vMissing
9. Voltage 1.8v1.8vLDR U300 (back)

Deep Dive Buck Converters & LDRs

Vram VRMs U701 & U801

R9 370 U701
R9 370 U801

Both are APW7165C https://datasheetspdf.com/pdf-file/971451/AnpecElectronicsCoropration/APW7165C/1 these appear to drive the Vram and VDDCI MOSFETS.

Check pins 1 (BOOT) and pin 5 (VCC)

U701 Pins

  • 1 BOOT -> 12v
  • 5 VCC -> 12v
  • 7 COMP -> 0.4 (<0.6 disable)

U801 Pins

  • 1 BOOT -> 11.69v
  • 5 VCC -> 12v
  • 7 COMP -> 0.4 (<0.6 disable)
R9 370 U200

I don’t actually know what C23 57Z is.

R9 370 U900 APW8713A

PWM APW8713A https://datasheetspdf.com/pdf-file/1091961/ANPEC/APW8713A/1

L900 is PEX, measuring healthy 1.0v

Check pins:

  • 1 POK -> 3.3v
  • 2 EN -> 5v
  • 20 BOOT
  • 8,9,22 VIN
  • 21 LDO
R9 370 U300

This is an LDR https://datasheet.lcsc.com/lcsc/1912111437_Anpec-Elec-APL5932AKAI-TRG_C351167.pdf

Check Pins:

  • 1 POK -> 0.9v
  • 2 EN -> 3.3v
  • 3 VIN -> 3.3v
  • 6 VOUT -> 1.8v

Looks healthy. This is the 1.8v source.

R9 370 U601

This is the PWM for the 3 phase Vcore VRM https://www.onsemi.com/pdf/datasheet/ncp5395t-d.pdf

Pins to check:

  • 24 VCC ->
  • 33 EN ->
  • 34 VR_RDY ->