Dometic SMP 190-03 70270-9717 Resistor Types, Values, and Replacement Guidelines

User question

what resistors are used in a dometic smp 190-03 70270.9717

Artificial Intelligence Response

Direct answer to the question

‣ Dometic does not publish a public bill-of-materials for the SMP 190-03 (P/N 70270-9717), so an official list of every resistor type, value, tolerance and power rating is not available in open literature.
‣ Field experience and teardown photos show that the converter contains the usual SMPS resistor sets:
 • Fusible inrush/PFC resistors (wire-wound, 2–5 Ω, 5–7 W, flame-proof)
 • HV start-up/bias resistors (100–470 kΩ, 0.5 W, metal-film)
 • Current-sense shunts (0.01–0.1 Ω, 1–3 W, 1 % or better, metal-strip)
 • Feedback/voltage-divider resistors (10 k–240 kΩ, 0.25 W, 1 %)
 • Snubber/RC-damping resistors (22–220 Ω, 0.5 W)
 • Bleeder resistors across the bulk cap (100–220 kΩ, 0.5 W, ≥250 V rating)
‣ To know the exact value of a specific resistor you must:
 1. Read the colour-code or SMD marking on the intact part, or
 2. Measure it out-of-circuit, or
 3. Obtain the service schematic from Dometic or an authorised service centre.

Detailed problem analysis

Switch-mode converters such as the SMP 190-03 follow a fairly standard topology (rectifier + PFC/primary switch + HF transformer + synchronous rectifier + output stage). Each functional block uses predictable resistor roles:

1. Primary-side start-up path
   • One or two high-value (100–470 kΩ) resistors connect the 325 VDC bulk rail to the VCC pin of the PWM or PFC controller (often UC384x, ICE2x, LNK series, etc.).
   • Power rating: 0.25–0.5 W.
2. Current-sense network
   • A low-Ω, precision shunt (0.01–0.1 Ω, 1–3 W) in the source of the main MOSFET. Value sets the converter’s over-current trip at ≈0.5–1.0 V sense level.
3. Snubber / RCD clamp
   • 47–220 Ω, 0.5–1 W carbon or metal-film in series with 1–4.7 nF across primary switch or transformer.
4. Inrush limiting / fusible resistor
   • Wire-wound cement or metal-oxide, 2–10 Ω, 5–7 W, flame-proof; doubles as an inexpensive fuse.
5. Bulk-cap bleeder
   • 100–220 kΩ, 0.5 W, ≥500 V rating, safety-rated (HVR or metal-film).
6. Feedback divider (secondary)
   • 2- or 3-resistor ladder feeding the optocoupler/ TL431. Typical total impedance 50–250 kΩ; 1 % metal-film.
7. EMI / RC damping in the output filter
   • 1–10 Ω, 0.25 W or SMT 1206, used in RCC “snubbers” across the output inductors/capacitors.

Because these values are “text-book,” an experienced technician can often deduce a missing resistor’s value by topology, nearby IC pin functions, and the expected control voltage.

Current information and trends

Online component databases (Oct-2023 → 2024) show that:
• Metal-strip current sense resistors with Kelvin pads are now common drop-in replacements (Bourns CRM2512, Vishay WSL2512).
• Flame-proof MOX parts remain industry standard for inrush fusible roles (KOA MF72, Yageo FMP).
• Many new SMPS designs are migrating from discrete start-up resistors to native HV start-up MOSFETs inside the PWM IC, but Dometic SMP 190-03 is an older design still using discrete resistors, per teardown images circulated on RV-repair forums in 2023.

Supporting explanations and details

– Colour-code quick recall (4-band):
Yellow-Violet-Brown = 470 Ω, ±5 %.
Brown-Black-Red = 1 kΩ, ±2 %.

– SMD code “R047” = 0.047 Ω; “1002” = 10 kΩ.
– Typical TL431 feedback divider equation:
\[V{OUT} = V{REF} \left( 1 + \frac{R{upper}}{R{lower}} \right) \]
With V_REF ≈ 2.5 V, a 5-V rail often uses R_lower ≈ 2.4 kΩ and R_upper ≈ 2.6 kΩ × (5/2.5 – 1) ≈ 2.4 kΩ; both 1 %.

Ethical and legal aspects

• Schematics are Dometic intellectual property; distributing them without permission can violate IP law.
• Replacing safety-critical resistors with incorrect types can breach UL/EN 60335 compliance, exposing the user to shock/fire hazards.

Practical guidelines

1. Photograph the PCB and note the reference designator (e.g., R37).
2. If charred, lift one pad and measure the trace width/length to estimate dissipation—use at least original wattage.
3. Prefer 105 °C, flame-proof or metal-film parts for primary-side circuitry.
4. After replacement, perform:
   a. Hi-pot / insulation test (1.5 kVAC primary-to-secondary).
   b. Load-test at 10 %, 50 %, 100 % load while monitoring ripple and MOSFET temperature.

Possible disclaimers or additional notes

‣ Without the exact schematic, any value proposed is an engineering estimate; verify in-circuit behaviour.
‣ Units may have board revisions—part numbers and values can differ.

Suggestions for further research

• Request the SMP 190-03 service file via Dometic’s authorised service portal.
• Search RV-electronics communities (iRV2, DIY Chat, ElektroTanya) for photo-documented repairs.
• Reverse-engineer the feedback path to cross-check output set-points; adjust resistor choices accordingly.

Brief summary

Dometic does not publicly list resistor values for the SMP 190-03 / 70270-9717. The unit uses the standard SMPS resistor set: inrush/fusible (2–10 Ω, 5–7 W), HV start-up (100–470 kΩ), precision shunts (≈0.05 Ω), feedback dividers (10–240 kΩ, 1 %), snubber/bleeder parts. To identify or replace any specific resistor, rely on the board’s markings, direct measurement, or an official service schematic obtained from Dometic or an authorised technician, and always match resistance, tolerance, wattage, and flame-proof rating for safety.

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.