Plugable TBT4-UD5: problems, parts and running costs

Checked: 2026-10-25

Summary

The main risk is host compatibility, not the dock: both HDMI outputs work only when the host supplies two native video streams, and base M1/M2 Macs usually give one. A functioning unit costs about $2.92-$5.84 a year in electricity at an illustrative 5-10 W, plus a possible $39.50 replacement power adapter after warranty. It is a good buy at $170 or less new; at $199.95 it matches standard pricing, and above $220 it is worth cross-shopping the TBT4-UDX1.

Common problems and fixes

Dual HDMI not recognized on some hosts — February 2026 cases: a Lenovo Legion Pro 7 owner found each HDMI worked alone but not together, and Plugable concluded the host ports lacked native Thunderbolt/TB4 dual-output capability; ThinkPad E16 Gen3 and Dell 14 Plus 2-in-1 owners reported the same. Fix: verify the exact laptop’s display-stream capability before ordering; use one display direct to the laptop if needed. Warranty: not a hardware defect; Plugable support continued by email with no published final resolution. [10][19]
Intermittent HDMI/VGA dropout — a September 2025 Dell Pro 14 case showed a second screen disappearing with roughly one-second flicker over HDMI-to-VGA adapters. Fix: use the included Thunderbolt 4 cable, check adapter models and exact laptop ID; no final fix was posted publicly. [9]
Total power failure — an August 2026 owner reported no power or LEDs after about five months, with outlets and peripherals tested. Fix: verify a known-good AC outlet and cord; support moved the case to email. This is one report, not an established failure rate. [11]
External 2.5GbE adapter slowdown through the dock — a September 2026 owner measured 136-148 Mbps receive via the rear USB-C and about 159 Mbps via downstream Thunderbolt 4, against above 2 Gbps transmit, for a Plugable USBC-E2500. Fix: plug the adapter direct when speed matters; the built-in 1 Gbps Ethernet performed better in the same path. [12]
No firmware available for blanking issues — in June 2025 Plugable said no TBT4-UD5 firmware update was available and directed the owner to private troubleshooting. Fix: do not install firmware meant for the TBT4-UDZ. [13]
USB and peripheral wake problems — forum posts report front USB-A ports not seeing mouse or keyboard, headset not reappearing after wake, and Ethernet failing to obtain an IP. These may come from host power management, permissions or cables; no sampled incidence was published. [8]
60 Hz ceiling on HDMI 2.0 — the two rear HDMI outputs are HDMI 2.0, so 4K runs at 60 Hz and 4K/120 Hz or higher is not available from this dock. Fix: connect high-refresh monitors directly to the computer. [1][3]
Single downstream Thunderbolt 4 port — with two HDMI displays occupying both video streams, only one downstream Thunderbolt 4 port remains for accessories. Fix: cross-shop a dock with two downstream Thunderbolt 4 ports if multiple Thunderbolt peripherals are needed. [1][2][17]

Parts and consumables

Replacement power adapter (PSU model FJ-SW202721006400, listing code PS-TBT4-UD5) — $39.50 refurbished on the Plugable eBay store, shown as over 10 in stock, free US 2-4 day shipping, 30-day returns. Replace only if diagnosed failed; the original supply is 21.0 V/6.4 A, about 134 W rated. [15][16]
SD and microSD cards — optional; not included. UHS-II ceiling is 312 MB/s and needs suitable media. No card is a required consumable. [1]
Ethernet cable — standard Cat5e/Cat6, not included. Replace only if damaged; the port stays 1 Gbps. [1]
Headset — 3.5 mm TRRS combo jack; no headset included, no proprietary consumable. [1]
USB-C to DisplayPort or HDMI adapter — optional for a display on the downstream Thunderbolt 4 port. Not included; unlike the TBT4-UDX1 kit, no adapter ships in the box. [1][17]

Yearly running cost

No subscription is required for basic native Thunderbolt 4 operation. Electricity is the only recurring cost, and Plugable publishes a 134 W supply rating, not a measured draw, so the figures below are illustrative at $0.20 per kWh over 8 hours a day for 365 days (2,920 powered hours): 5 W average gives 14.6 kWh, about $2.92 a year; 10 W gives 29.2 kWh, about $5.84 a year. If dock-delivered laptop charging adds an average 40 W over those hours, that adds 116.8 kWh, about $23.36 a year, before conversion losses, and that energy powers the laptop rather than the dock alone. A single post-warranty adapter replacement adds $39.50 to the $199.95 direct list price, giving $239.45 before tax; that is a scenario, not a prediction that every unit needs a new adapter. [1][11][14][16]

When it is a good buy

Direct from Plugable: $199.95 with free continental US shipping above $35, a 30-day money-back position and a two-year limited warranty. B&H listed $199.95 new and $163.95 used; Best Buy and Adorama showed $199.95; Walmart Business showed $199.95; Office Depot showed $223.99. A good new unit is attractive at $170 or less through an authorized channel; $170-$200 is consistent with observed standard new pricing; above $220 it is worth cross-shopping the TBT4-UDX1 at $249.95 for 2.5GbE and two downstream Thunderbolt 4 ports. Alternatives: the Plugable TBT4-UDX1 at $249.95 for a fast LAN and more Thunderbolt peripherals; the CalDigit TS4 at $379.99 (out of stock on the opened listing) for a creative workstation needing more ports; the Plugable TBT4-UDZ at $289.99 for up to four Windows displays, with different power supplies and firmware. [1][5][6][7][14][17][18][20][21]