TCS 1557 | B-MB4 21-Pin Motherboard w/ Keep-Alive - Bachmann 4-4-0 & Brass | HO Scale
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Description
The TCS B-MB4 is a replacement motherboard for the Bachmann Richmond 4-4-0, accepting a 21-pin WOW121 or EU621 decoder for a quick, clean install. An on-board KA2 Keep-Alive® keeps the little 4-4-0 running smoothly over dirty track and frogs, and the universal layout also makes the B-MB4 a great choice for brass models.
Browse more DCC Accessories and DCC Decoders, or shop the full Train Control Systems lineup.
The B-MB4 ships in two 21-pin connector heights so the board seats correctly against your decoder. Choose Low Pins for TCS decoders (WOWSound 121, EU621), or High Pins for Soundtraxx & ESU decoders — just match the option to your decoder’s brand.
- Replacement motherboard for the Bachmann Richmond 4-4-0.
- Accepts a 21-pin WOW121 or EU621 decoder for fast installation.
- On-board KA2 Keep-Alive® for stutter-free running.
- Universal design — also well suited to brass model installs.
| Brand | Train Control Systems (TCS) |
| Item Number | 1557 (B-MB4) |
| Type | DCC Motherboard / Decoder Interface |
| Decoder Interface | 21-pin (WOW121 or EU621) |
| On-board Keep-Alive | Yes (KA2) |
| Fits | Bachmann Richmond 4-4-0; universal / brass |
| Scale | HO Scale |
| Condition | New |
What does this motherboard do?
It replaces the factory circuit board so you can drop in a 21-pin WOW121 or EU621 decoder, and it adds an on-board KA2 Keep-Alive for smooth running.
What locomotive is it for?
It is designed for the Bachmann Richmond 4-4-0, and its universal layout also suits many brass models.
Does it include a decoder?
No — add a WOW121 or EU621 decoder to complete the install.