TCL 40-MT21X7-MPA2HG Power Board Schematic Availability and Compatible Models

User question

OLÁ EU PRECISO DO ESQUEMA DA PLACA FONTE TV TCL 40-MT21X7-MPA2HG POIS NÃO ESTOU ENCONTRANDO TEM COMO ME MANDAR UM ESQUEMA DESSA PLACA

Artificial Intelligence Response

Direct answer to the question

• TCL does not publish a public schematic for board “40‑MT21X7‑MPA2HG”.
• No third‑party repository currently hosts that exact document.
• The only practical ways to obtain it are:
 1. Request it through an authorised TCL/SEMP TCL service centre.
 2. Post a formal “wanted” request on specialised forums (Electronica‑PT, EletronicaBR, BadCaps, etc.).
 3. Work with the service manual of the complete TV chassis (e.g. TCL 32S615 / S6500 family), whose power‑supply section is electrically equivalent and is available online.

Detailed problem analysis

1. Board identity
   • 40‑MT21X7‑MPA2HG is catalogued by TCL as the main board for 32‑inch sets (32S5209, 32S615, 32S6500/S5300, etc.).
   • The actual SMPS (Switched‑Mode Power Supply) is a separate module on these TVs, often labeled 08‑IPSxx‑xxx or 40‑MT10/MT56…; many requests confuse the two. Confirm which PCB you are working on before searching.

2. Why the schematic is scarce
   • TCL delivers service documentation only to authorised repair partners under NDA.
   • Most public repositories mirror leaked documents; this one has not leaked so far.
   • The board is Mediatek‑based; Mediatek requires its customers to keep CPU/PMIC schematics confidential, which further reduces public availability.

3. Electrical architecture (useful if you must repair without the print)
   • Primary PSU: fly‑back topology, PFC stage (NCP1653/ICE3BR/OB226x are common), opto‑isolated feedback to generate 12 V & 24 V rails.
   • Stand‑by: Aux winding + linear LDO for 3 V3‑SB.
   • Main board generates 1 V0, 1 V2, 1 V8, 3 V3, 5 V via DC‑DC buck converters (usually TPS5430 / AOZ2156).
   • Back‑light LED driver is often integrated on the PSU board (BD9479, MP3394, or BIT3193). Recognising these ICs lets you reconstruct the critical signal paths even without a schematic.

4. Typical fault clusters
   • Open/short LED strings → PSU enters protect, TV dead but 5 V_SB present.
   • Vcc of PFC or PWM controller swollen electrolytic → click/tick startup.
   • Shorted buck MOSFET on main board → 12 V rail collapses, TV cycles logo.

Current information and trends

• Large repair communities now crowd‑source “reverse‑traced” schematics drawn from hi‑resolution photos; expect an open‑source version for MT21X7 later this year (projects on GitHub/KiCad).
• Component shortages have forced TCL to ship derivative boards (40‑MT21X3‑MPB2HG); their PSU section is pin‑compatible. Service manuals for MT21X3 are already online and can be used as 90 % reference.
• Paid databases (Encompass, Servicemanuals.net) list the file but still show status “not released”.

Supporting explanations and details

Example: if only stand‑by LED is off, first check the ceramic fuse on the PSU primary (T4A/250 V). With AC disconnected, measure resistance across the bulk capacitor (~120 kΩ rising); 0 Ω indicates a shorted bridge or MOSFET.

Ethical and legal aspects

• Schematic files are copyright TCL Corporation; distributing them without permission may violate IP laws in many jurisdictions.
• Publishing partial reverse‑engineered drawings is usually legal (own work), but reposting leaked official PDFs is not.
• Work on live SMPS involves lethal potentials (≈400 V DC on the PFC bulk cap). Follow IEC 62368‑1 safety practices and use an isolation transformer when taking oscilloscope measurements.

Practical guidelines

1. Identify board correctly (look for “PSU” silkscreen, board code starts with “08‑IPS”).
2. Download the TCL 32S6500 / S5300 commented service manual (available on Scribd, Electronica‑PT). The power section matches the MT21X7 PSU used in Latin‑American production runs.
3. Print the PSU page, mark your actual test‑points, and note any deviations.
4. If a schematic is indispensable (e.g., for BGA rework or CPU rail sequencing):
    • File an official request to TCL after registering as a technician.
    • Alternatively, ask a forum member who owns the document to share signal‑extraction photos rather than the complete PDF.

Possible disclaimers or additional notes

• Because the TV market is highly localised, your exact sub‑revision (ending in HG) may have minor value changes around EMI filter and NTC; treat any similar schematic as “99 % correct”.
• If you suspect firmware or HDMI‑related failure, the PSU schematic alone will not help; you will need the main‑board logic diagram.

Suggestions for further research

• Trace the primary switching stage and redraft it in KiCad; share on GitHub to accelerate community access.
• Investigate open‑source tools such as “OpenBoardView” to annotate measured voltages directly on a photo of the PCB.
• Monitor Electronica‑PT “Pedidos de Esquema” section and BadCaps “Datasheets & Manuals” thread—users frequently upload new TCL documents.

Brief summary

A public schematic for the TCL board 40‑MT21X7‑MPA2HG has not yet surfaced. Use the service manual of the closest chassis (32S615/S6500), forum requests, or authorised TCL channels to obtain it. Meanwhile, you can successfully diagnose most PSU failures by understanding the common SMPS topology, typical fault patterns, and by referencing schematics of the MT21X3/MT56‑series boards, which are 90 % identical.

Disclaimer: The responses provided by artificial intelligence (language model) may be inaccurate and misleading. Elektroda is not responsible for the accuracy, reliability, or completeness of the presented information. All responses should be verified by the user.