{
  "checked_on": "2026-10-19",
  "scope": "PC 1715 drawing 56-330-2770-5; match to museum W/M specimen unverified",
  "publication": "Originals linked at source hosts, not mirrored; guide is original commentary, not a complete manual translation. No bench-qualified substitutes.",
  "sources": [
    {
      "id": "manual",
      "title": "Robotron · 1715 Servicehandbuch",
      "url": "https://www.tiffe.de/Robotron/PC1715/PC-1715-Servicemanual.pdf#page=95",
      "credit": "VEB Robotron Büromaschinenwerk Sömmerda; archive: tiffe.de",
      "locator": "§1.9; 93–101 → PDF 95–103",
      "sha256": "e810e4722d889a7e357e192486da3a8004b1fd08aca1c0dcef4f3bbc5b66021d",
      "bytes": 15312406,
      "pdf_pages": 210,
      "review": "PSU chapter OCR navigation; schematic and service check pages visually checked"
    },
    {
      "id": "drawings",
      "title": "Robotron · Schaltpläne",
      "url": "https://www.tiffe.de/Robotron/PC1715/PC-1715-Schaltplaene.pdf#page=20",
      "credit": "Robotron; archive: tiffe.de",
      "locator": "56-330-2770-5; PDF 18–20",
      "sha256": "9d020e9dd41662f85b6a9a44e300cc9800ef20284c2a689e005f69a84f6e3fd3",
      "bytes": 31837204,
      "pdf_pages": 50,
      "review": "PDF pages 18,19,20 visually inspected; schematic rotated for reading",
      "drawings": {
        "18": "63-330-2760-4",
        "19": "63-330-2767-8",
        "20": "56-330-2770-5"
      }
    },
    {
      "id": "user",
      "title": "Robotron · Bedienungsanleitung 1715 / 1715W",
      "url": "https://xepb.org/robotron/docs/pc_manu.pdf",
      "credit": "Robotron; digitisation: Ulrich Zander; mirror: XEPb.org",
      "locator": "1715 / 1715W"
    },
    {
      "id": "archive",
      "title": "Robotron 1715 unofficial support",
      "url": "https://xepb.org/robotron/docs.html",
      "credit": "XEPb.org / DtZ; links credit Ulrich Zander and Jens Müller",
      "locator": "1715W archive: https://xepb.org/robotron/docs/1715w.zip"
    },
    {
      "id": "kt818",
      "title": "КТ818 · January 2011, rev. 1.0",
      "url": "https://arbatex.ru/upload/iblock/731/731be24e9da6870ddfa9e7ea8ce684d8.pdf",
      "credit": "ОАО «ИНТЕГРАЛ», Minsk; mirror: Arbatex",
      "locator": "PDF 1–3; аАО.336.188 ТУ / 02",
      "sha256": "7beb2b0e39ae4bb56d0323d71c219d95713c8649bbedecfe946f4462a2437ac0",
      "review": "INTEGRAL manufacturer datasheet at third-party mirror; modern continuation of Soviet family, not proof of every historical lot"
    },
    {
      "id": "tip36",
      "title": "TIP35C / TIP36C · September 2008, rev. 5",
      "url": "https://www.st.com/resource/en/datasheet/tip35c.pdf",
      "credit": "STMicroelectronics",
      "locator": "PDF 1–3, 7; TIP36C is the PNP member"
    },
    {
      "id": "tip36-status",
      "title": "TIP36C · product status",
      "url": "https://www.st.com/en/power-transistors/tip36c.html",
      "credit": "STMicroelectronics",
      "locator": "Active; checked 2026-10-19"
    },
    {
      "id": "fjl",
      "title": "FJL6920 · January 2025, rev. 2",
      "url": "https://www.onsemi.com/download/data-sheet/pdf/fjl6920-d.pdf",
      "credit": "onsemi",
      "locator": "PDF 1–2; comparison only",
      "sha256": "e72447dabc976d3244f45e01c1ba7bd10eb254eb8f19ea5c44ccc505a6974398",
      "review": "Manufacturer data; comparison only, replacement not qualified"
    }
  ],
  "specimen_evidence": {
    "id": "psu002",
    "owner": "Danila",
    "specimen": "PSU002",
    "source_register": "https://github.com/ddanila/3d-models/blob/main/models/robotron-1715m/reference/owner-20261019-psu002.json",
    "owner_observations": [
      "PSU002 is otherwise identical to PSU001.",
      "One transistor, BU126, is missing."
    ],
    "visible_observations": [
      {
        "photo": "PXL_20261019_085745986.jpg",
        "observation": "PSU002 inventory label on component side."
      },
      {
        "photo": "PXL_20261019_085940666.MP.jpg",
        "observation": "Connector board marked 105-330-2757-7; rail labels 5N, 12N, 12P, 5P and 0V."
      }
    ],
    "limits": [
      "PSU002 is a separate specimen; owner comparison does not transfer PSU001 repair history or identify the installed museum supply.",
      "V15 is identified by placement correlation; full pin-to-net continuity is not verified. The fitted BU126 differs from SU169 in the reference drawing.",
      "Photographs support placement, markings and visible copper inspection; hidden connections and electrical condition are not established."
    ],
    "previews": [
      {
        "file": "photos/PXL_20261019_085745986.webp",
        "sha256": "e039d0e420c0206d80412f257fd7ead6d32a9cba630445e89723781419a3022b",
        "original": "PXL_20261019_085745986.jpg",
        "original_sha256": "1a3fe0aeed830e4462bb31ba623633248ae6d5d00417c9f1f423bc22f91f5ea1",
        "width": 1600,
        "height": 1205
      },
      {
        "file": "photos/PXL_20261019_085748827.webp",
        "sha256": "c8c3db03f254564f2cb8cde3809dee2f1ea3b9fbc713723dcbca0acafa2c959c",
        "original": "PXL_20261019_085748827.jpg",
        "original_sha256": "f0b6822b76a2ed1c501a3631ab72b267485c8eed50c44b6c57dc8675b673c42d",
        "width": 1600,
        "height": 1205
      },
      {
        "file": "photos/PXL_20261019_085903438.webp",
        "sha256": "57e5f62a0a858248f2f02be3fb52d58f03df50603fc89f63299b5212762d5314",
        "original": "PXL_20261019_085903438.jpg",
        "original_sha256": "29017b761210b36d2002aba54769c0e49a852319d0c30d0262346d30cf8e5cca",
        "width": 1600,
        "height": 1205
      },
      {
        "file": "photos/PXL_20261019_085940666.MP.webp",
        "sha256": "1044a2fb096ceb43854440aedd136082f783d2992a7153b136996eef5fd55a3b",
        "original": "PXL_20261019_085940666.MP.jpg",
        "original_sha256": "492b00c3debe720bdae94b38fe823ce56e72a561e8647d5db4054da62daf8a29",
        "width": 1205,
        "height": 1600
      }
    ],
    "comparison": {
      "specimen": "PSU001",
      "owner": "Danila",
      "source_register": "https://github.com/ddanila/3d-models/blob/main/models/robotron-1715m/reference/owner-20261019-psu001.json",
      "visible_observations": [
        {
          "photo": "PXL_20261019_091009588.jpg",
          "observation": "Transistor marked BU126 and 04 87 on a vertical plate heatsink."
        },
        {
          "photo": "PXL_20261019_091015286.jpg",
          "observation": "PSU001 inventory label and surrounding assembly visible."
        },
        {
          "photos": [
            "PXL_20261019_091012624.jpg",
            "PXL_20261019_085748827.jpg"
          ],
          "observation": "BU126 heatsink position in PSU001 corresponds visually to the empty heatsink position in PSU002, using the adjacent magnetic component, capacitor group and resistor pair as landmarks."
        }
      ],
      "limits": [
        "The populated and empty positions correlate with V15 in placement drawing 63-330-2760-4; no complete pin-to-net verification.",
        "The fitted BU126 does not establish factory population, repair history or qualification as a replacement for the reference drawing transistor."
      ],
      "previews": [
        {
          "file": "photos/PXL_20261019_091009588.webp",
          "sha256": "cda9f8d5c9bad2288a3fcb27826b52bfd1a837db138060f41e88a106a2fc39d7",
          "original": "PXL_20261019_091009588.jpg",
          "original_sha256": "a37cac14ea1a55fb8f93ce093ac79b5892b0a942078fbdeeaaef46f343855a6a",
          "width": 1600,
          "height": 1205
        },
        {
          "file": "photos/PXL_20261019_091015286.webp",
          "sha256": "31d34d39c343c3b029f72eec38bb818baaecb995a2a91884a834b922662839b9",
          "original": "PXL_20261019_091015286.jpg",
          "original_sha256": "c7fe307fc7ccbbb981ee4d44467d5f47dcab554470001f48ce9e180f1b3f2971",
          "width": 1600,
          "height": 1205
        }
      ],
      "completeness": {
        "observation": "Additional vertically mounted PCB absent",
        "evidence": "owner report",
        "reported_on": "2026-10-19",
        "board_identification": "Exact assembly/revision not established"
      },
      "disposition": {
        "owner_intent": "Retain for parts or possible custom PSU installation reusing enclosure and contacts",
        "status": "Not the current restoration focus; custom conversion is an option, not an implemented design"
      }
    },
    "layout_correlation": {
      "reference": "V15",
      "status": "placement-correlated; not continuity-tested",
      "fitted_PSU001": "BU126",
      "PSU002": "unpopulated",
      "reference_type": "SU169",
      "reference_role": "Primary switch for the Tr3 / 12PM flyback section",
      "placement_drawing": {
        "number": "63-330-2760-4",
        "pdf_page": 18
      },
      "schematic": {
        "number": "56-330-2770-5",
        "pdf_page": 20
      },
      "photos": [
        "PXL_20261019_091009588.jpg",
        "PXL_20261019_091012624.jpg",
        "PXL_20261019_085748827.jpg"
      ],
      "basis": "Vertical heatsink between R9/R10 and Tr3, next to the V11–V14 rectifier bank and C13–C15 group. The same landmarks locate the absent part in PSU002.",
      "remaining": "No complete pin-to-net trace or continuity measurement; factory population and BU126 replacement qualification remain unknown."
    },
    "connector_orientation": {
      "photo": "PXL_20261019_085940666.MP.jpg",
      "view": "Solder side with 105-330-2757-7 text upright",
      "pad_rails_left_to_right": [
        "5N",
        "12N",
        "12P",
        "12P",
        "5P",
        "5P",
        "0V",
        "0V",
        "0V"
      ],
      "limit": "Solder pad groups only; mating-face pin 1 is not established by these photographs."
    },
    "identification": {
      "shield_number": "043024",
      "pcb_serial_stamp": "none observed",
      "evidence": "owner report",
      "reported_on": "2026-10-19"
    },
    "completeness": {
      "observation": "Additional vertically mounted PCB absent",
      "evidence": "owner report",
      "reported_on": "2026-10-19",
      "board_identification": "Exact assembly/revision not established"
    },
    "disposition": {
      "owner_intent": "Retain for parts or possible custom PSU installation reusing enclosure and contacts",
      "status": "Not the current restoration focus; custom conversion is an option, not an implemented design"
    }
  },
  "additional_specimens": [
    {
      "id": "psu003",
      "owner": "Danila",
      "date": "2026-10-19",
      "specimen": "PSU003",
      "identification": {
        "metal_shield_serial_number": "010438",
        "evidence": "owner report",
        "reported_on": "2026-10-19"
      },
      "disposition": {
        "owner_intent": "Concentrate restoration work on PSU003"
      },
      "limits": [
        "Shield serial number is not a PCB serial number.",
        "Assembly completeness, electrical condition and schematic revision match have not been established."
      ],
      "source_register": "https://github.com/ddanila/3d-models/blob/main/models/robotron-1715m/reference/owner-20261019-psu003.json"
    }
  ]
}