Repair Agilent DSO-X 3012A Oscilloscope (Busted Power Supply)

Agilent_DSOX3012A_Scope_Repair.md

Repair Agilent DSO-X 3012A Oscilloscope (Busted Power Supply)

Main guide: https://etoast.net/posts/agilent_repair/

Repairing the power supply is not very feasible.

BOM (Parts to Buy)

• Power Supply: RPSG-160-12 [1x]
  • RPSG-160-12 Datasheet
• AC/DC Pins: SVH-21T-P1.1 [Need 8x, get 15x]
• Signal Pins: SXH-001T-P0.6 [Need 3x, get 10x]
• AC Input Housing: VHR-3N [Need 1x, get 2x]
• 8-wide DC Output Housing: VHR-8N [Need 1x, get 2x]
• Signal Housings: XHP-4 [Need 2x, get 4x]

Repair Plan

1. Buy parts.
2. Remove old power supply.
3. Install new power supply.
4. Wiring - Follow wiring diagram. Connect 3x GND, 3x +12V, and three extras (Neg Sense [-S] , Pos Sense [+S], PS_ON).
5. Adjust voltage up to 13V with trim pot, maybe. Suggested by etoast.net article.
6. Maybe: Wire the GND from the PS_ON to a GND on the scope supply. etoast.net article seemed to suggest they may be isolated.

Specs/Models

• Scope Model: Agilent DSO-X 3012A

  • May work for all 3000 and 2000 scope models.

• Original Power Supply: CCH0125F1-Z03A Rev A

  • Datasheet: https://www.alldatasheet.com/datasheet-pdf/view/568839/LINEAGEPOWER/CCH0125F1-Z03A.html
  • 125 watts, 12 V
  • 3.00 x 5.00 x 1.25” (215.9mm x 125.7mm x 38.1mm)
  • Remote Sense (compensates for up to 250mV Drop)
  • Remote on/off Control (A low signal turns the power supply off)
  • AC FAIL: Signal is high when AC input voltage signal is within specified regulation.
  • DC Good (PS OK): Signal is High when DC output voltage is within regulation.

Assessment of Options

• RPS-160-12 PSU vs. RPSG-160-12 PSU

  • The RPSG option has a "5vsb" (5V stand-by always-on) supply, whereas the RPS option does not have a standby. Standby not needed for this.
  • Forum discussion suggests that this stand-by is essential/important, so get the RPSG option. Worst case, just don't use it.
  • Datasheet seems to suggest that the "PS-ON" option is only on the RPSG model. Thus, we get it.

• RPSG-160-12

  • Has standby power (5V).
  • Power on: PS-ON = "Hi". Power off: PS-ON = "Low"
  • Note: Datasheet pinout suggests it's a "PS-ON" inverted.

Alternative Guides/Discussions

• https://www.eevblog.com/forum/repair/dso-x-3024a-power-supply-defect/?all
• https://www.eevblog.com/forum/repair/resistor-of-a-keysight-ps-doubt!/?all

Wiring Diagrams

Original Wiring

New Wiring Diagram - RPSG-160-12

Pinout of IEC 60320 (C13/C14) for Validation

aglient_scope_wires_orig.yaml

connectors:
  J1 (AC Input):
    type: Molex 640445-3 on PCB
    subtype: female
    pinlabels: [Line, N/C, Neutral]
  J4 (DC Output):
    type: Molex 640445-6 on PCB
    subtype: female
    pinlabels: [V1, V1, V1, RTN, RTN, RTN]
  J6 (Status):
    type: Molex 640456-6 on PCB
    subtype: female
    pinlabels: [RTN, Neg Sense, Pos Sense, AC Fail, PS OK, Remote PS ON]

  AC Input:
    subtype: female
    pinlabels: [Line, N/C, Neutral]

  Main Connector:
    subtype: female
    pinlabels: [V1, V1, V1, RTN, RTN, RTN, Neg Sense, Pos Sense, Remote PS ON]

cables:
  AC Wire:
    color_code: DIN
    wirecount: 2

  Main Wire:
    color_code: DIN
    wirecount: 9

connections:
  -
    - J1 (AC Input): [1, 3]
    - AC Wire: [1, 2]
    - AC Input: [1, 3]

  -
    - J4 (DC Output): [1-6]
    - Main Wire: [1-6]
    - Main Connector: [1-6]

  -
    - J6 (Status): [2, 3, 6]
    - Main Wire: [7, 8, 9]
    - Main Connector: [7, 8, 9]

aglient_scope_wires_rpsg.yaml

connectors:
  CN1 (AC Input):
    type: JST B3P-VH on PCB, JST SVH-21T-P1.1 on wire, JST VHR housing
    subtype: female
    pinlabels: [Neutral, N/C, Line]
  CN2 (DC Output):
    type: JST B8P-VH on PCB, JST SVH-21T-P1.1 on wire, JST VHR housing
    subtype: female
    pinlabels: [+V, +V, +V, +V, -V, -V, -V, -V]
  CN3 (Power Good):
    type: JST B4B-XH on PCB, JST SXH-001T-P0.6 on wire, JST XHP housing
    subtype: female
    pinlabels: [PG, GND, Neg Sense, Pos Sense]
  CN901 (Standby):
    type: JST B-XH on PCB, JST SXH-001T on wire, JST XHP housing
    subtype: female
    pinlabels: [N_PS_ON, GND, 5VSB, GND]

  AC Input:
    subtype: female
    pinlabels: [Line, N/C, Neutral]

  Main Connector:
    subtype: female
    pinlabels: [V1, V1, V1, RTN, RTN, RTN, Neg Sense, Pos Sense, Remote PS ON]

cables:
  AC Wire:
    # gauge: 0.25 mm2
    # length: 0.2
    color_code: DIN
    wirecount: 2

  Main Wire:
    # gauge: 0.25 mm2
    # length: 0.2
    color_code: DIN
    wirecount: 9

  Pigtail Loopback:
    # gauge: 0.25 mm2
    # length: 0.2
    color_code: DIN
    wirecount: 1

connections:
  -
    - CN1 (AC Input): [3, 1]
    - AC Wire: [1, 2]
    - AC Input: [1, 3]

  -
    - CN2 (DC Output): [1-3, 5-7]
    - Main Wire: [1-6]
    - Main Connector: [1-6]

  -
    - CN3 (Power Good): [3, 4]
    - Main Wire: [7, 8]
    - Main Connector: [7, 8]

  -
    - CN901 (Standby): [1]
    - Main Wire: [9]
    - Main Connector: [9]

  # TODO: Make this loopback pigtail work.
  # -
  #   # - Main Wire: [10]
  #   - CN2 (DC Output): [8]
  #   - Pigtail Loopback: [1]
  #   - CN901 (Standby): [2]