G649D Industrial PLC Controller: Complete Technical Guide and Applications
On this page
What is the G649D?
The G649D is a graphic LCD display module from Seiko Instruments (SII), made in Japan — not a PLC controller as the listing title suggests. The board itself carries the maker's silkscreen: G649D JAPAN SII, on a TW-22 94V-0 PCB. This is the full display assembly: the LCD panel in its metal frame, a CCFL backlight tube along the bottom edge, and the driver board on the back with the SII custom driver packages and OKI M6294A-01 column drivers already fitted. This record covers three complete modules, each with the protective film still on the glass, intake recorded 26 December 2025, record weight 1 kg for the lot. Nine photos and an inspection video document these exact units, including the maker's marks and the driver-board layout.
Part details
| Field | Value |
|---|---|
| Brand / origin | Seiko Instruments Inc. (SII) — silkscreen G649D JAPAN SII |
| Type | Monochrome graphic LCD module with integrated driver PCB and CCFL backlight |
| PCB | TW-22, 94V-0 flammability grade (board marking) |
| Drivers on board | Eleven large QFP packages (IC1–IC11): SII custom driver ICs in the top row, OKI M6294A-01 (2022 date-marked) on the lower rows; SOP-level support ICs and tantalum caps around IC12–IC19 |
| Backlight | CCFL tube in a metal channel along the bottom edge, white high-voltage leads (UL E203950 AWM) to a brown 6-pin connector |
| Condition | New with protective film on the glass; service-warranty seal (techjxv, dated 6 July 2025) on each board |
| Lot | 3 complete modules, Made in Japan; intake 2025-12-26, record weight 1 kg |
Values are read from the silkscreen, the IC markings and the photographed construction; the record adds the intake date, quantity and weight.
What the driver board tells you
Older graphic LCD modules ship as two halves — a bare glass panel and a separate driver board joined by a zebra strip — but the G649D integrates the whole chain on one green PCB. The back shows the full driver stack: a row of eight SII custom QFP packages across the top (IC1–IC8), three more large packages below including the OKI M6294A-01 with a 2022 date mark, and the support passives bunched around IC12–IC19 on the right edge, where the interface header sits. The CCFL backlight runs in a metal channel along the bottom edge, and its white high-voltage leads — printed with the UL E203950 AWM file number — land on a brown 6-pin connector for the inverter feed.
Three identical modules make up this record, photographed together in one frame and individually. Each glass still carries its protective film, the frames are unmarked, and each board carries the service shop's dated seal (6 July 2025). For keeping an ageing HMI, tester or instrument alive, a same-model display with its original SII driver chain avoids the adapter boards and timing rework that a third-party substitute usually drags in — the module drops into the original bezel and connects as the OEM intended.
Photos and video
All images below are original KOEED warehouse photos. Click any photo to view it full size.
For a colour industrial panel from the same shelf, see the AUO B084SN03 8.4-inch LCD — documented the same way, warehouse photos included.
Sourcing help
KOEED supplies this product, in active and EOL stock. Send the part number for a quote.
Need a quote for this part?
Send us the part number or article link — we will confirm price, availability and lead time.
