Have an LGB 70255 starter set which came with a steam loco (in appearance almost identical to the current LGB 20753) and a yellow diesel shunter (road number 3005, product ID 20900.1).
Both come stock with primitive LGB 55020 (steam) / 55021 (diesel) decoders. I could write these OK with the LGB 55015 handset. However, when I upgraded to a Roco z21 XL I discovered that I could read/write from steam train but not the diesel. When I opened them up and moved the decoder from the diesel to the steam I could then read/write it OK.
The 55020 decoder died, so I removed both the old decoders and replaced them with Zimo decoders, fitted with harnesses to allow them to fit into the existing LGB "direct decoder" interface. To my surprise, I experienced a similar problem - I cannot reliably read the Zimo decoder when it is fitted into the diesel. Removing it from the harness and putting it into the Zimo decoder tester it reads fine.
Note: this is a programming issue. I can run the decoder fine, I just can't read the CVs. I haven't tried writing them via the Roco.
Specific example:
* read CV1 fitted to diesel: 35 (0x23)
* read CV1 fitted to decoder tester: 3 (0x3) - this is also the correct value (I can drive the train using CV3)
It's not a massive problem since I can program the decoder in the tester, but that also involves removing the body and the decoder rather than just putting the loco on the programming track. I just wondered if anyone has any ideas as to the cause of the issues?
I do have one thought: the loco has a pair of alternatively flashing lights that run directly from track power. I wonder whether the circuit to drive those lights is causing noise that is confusing the reading. I don't know if there's a way to turn them off.
Both come stock with primitive LGB 55020 (steam) / 55021 (diesel) decoders. I could write these OK with the LGB 55015 handset. However, when I upgraded to a Roco z21 XL I discovered that I could read/write from steam train but not the diesel. When I opened them up and moved the decoder from the diesel to the steam I could then read/write it OK.
The 55020 decoder died, so I removed both the old decoders and replaced them with Zimo decoders, fitted with harnesses to allow them to fit into the existing LGB "direct decoder" interface. To my surprise, I experienced a similar problem - I cannot reliably read the Zimo decoder when it is fitted into the diesel. Removing it from the harness and putting it into the Zimo decoder tester it reads fine.
Note: this is a programming issue. I can run the decoder fine, I just can't read the CVs. I haven't tried writing them via the Roco.
Specific example:
* read CV1 fitted to diesel: 35 (0x23)
* read CV1 fitted to decoder tester: 3 (0x3) - this is also the correct value (I can drive the train using CV3)
It's not a massive problem since I can program the decoder in the tester, but that also involves removing the body and the decoder rather than just putting the loco on the programming track. I just wondered if anyone has any ideas as to the cause of the issues?
I do have one thought: the loco has a pair of alternatively flashing lights that run directly from track power. I wonder whether the circuit to drive those lights is causing noise that is confusing the reading. I don't know if there's a way to turn them off.