Zimo MX648 and Hornby TTS chip

[jgsi]

This is a bit strange, but have just got a Honby 8F that is fitted with an MX648 with heavy freight sound. It stalls going through a Peco y point. All the usual stuff done --  clean , clean etc.

Still stalling. Switched to a TTS and it on shunt speed, even slower, goes over the points. No stalling. The issue is , I dont think the TTS chip will in the smoke box (older 8 pin model - not in the tender). 

Before I start messing about, is there a CV setting/  hack to make the MX648 not so fussy? Fitting a stay alive , is one solution, I know.

[SRman]

Just a thought: could the loco be momentarily shorting through the points? The Zimo decoder has overload protection built-in, the TTS does not.

[jgsi]

11 minutes ago, SRman said:

Just a thought: could the loco be momentarily shorting through the points? The Zimo decoder has overload protection built-in, the TTS does not.

That would explain the running difference.  I think it is a stay alive solution though.

[RAF96]

TTS indeed has overload protection on the motor circuit but not on the function outputs.

[jgsi]

I've programmed a simple cariable speed program for it and at the  moment it is behaving itself. Just increased the shunt speed a tiny bit. Touch wood.

[jgsi]

Just an update for this thread...  

YouChoos Life Link stay alive capacitor fitted but having to use that tiny extra circuit board to make it work for my 8F.

It now runs extremely slowly over whatever.

I've had to to extend the wires off the chip so that the stay alive is in the tender -- not a pretty solution until I sort it though with a bit of creative inspiration.