Shimano SC-E8000 computer / controller / display turns off

[zez3]

I probably saw/read somewhere that shimano does not recomend anymore since the new 8000 model to attach the light to this computer and instead they made special connectors on the engine itself but I had to try.
I had anyway an extra cable that I could use/cut and fit to a pretty strong light that I bought cheap from ebay(60000Lm 16x XM-T6 LED 3Mode Cycling Bicycle Light) I think it's rated 8.4 Volt compared to 6V officially shimano blessed models.
So it looks like it's working at least on one side but then the mode-trigger/shifter stops working(does not switch anymore from/to eco/trail/boost) and that even if the light is not yet turned on. I mean, I see the green led(power status) on the light back button but it's not yet on. It does turn on/off and I can use it no problem there. The computer it self still works(switches to different odo/dst/cadence/etc. data), it's just the trigger that can't seem to work.
Is is perhaps digital signaling?? and I am jamming that signal with the light ? Can someone please shed some light on this? Can I fix it with some circuit filter perhaps?
Anyway another strange thing is that if I connect the light before powering on the battery the computer stays and remains off and only starts if I reconnect(remove and reattach) the light back to it. It can't be something like a short circuit is it ? I know it also sucks a lot of amps when it's on but at this stage it's not even turned on.
Has someone experienced this, opinions ?
Thanks in advance.

In the meantime I did some measurements and it looks like the voltage coming out of computer is 8V and when I connect my light and power it on, it drops to 6.5V. Unfortunately I cannot measure amps because the fluke multimeter that I used is a real "fluke" and only measures ~ intensity
Any ideas or suggestions are hardly appreciated

 

[zez3]

Updates, I tried connecting the light directly on the engine, near the speed sensor and where there computer comes in, same effect .

 

[amberwolf]

If it works fine without the light, then the light is drawing too much current (even when "off", it's probably not really completely "off", like a lot of electronics these days), causing the voltage to drop too much.

You'd have to use a separate power source for the light, or use a light that does not draw any more current than the system can safely provide.


If you hook up things that draw too much current long enough, you can damage the voltage regulators in the supply, and then the rest of the system won't work (or not correctly).


If your Fluke is only a DVM, you might check places like Harbor Freight and teh like for their cheap (sometimes free with purchase) multimeters. If it's actually a DMM but current doesn't work, you can replace the fuse in them (but it's expensive, $10-$20) to fix it.


BTW, if it's really a 60,000 lumen light, it probably draws almost a hundred amps at 6v, and will need quite a battery (completely separate from the bike) to run it, and it will probably be hot enough to keep you warm in freezing weather (possibly even cook things on), . Since that level of lighting is usually what they use for stadiums and such, it will blind anyone looking at it, so the police will probably remove you from the road as soon as you turn it on.

So I suspect the ebay specs are lies, like many such ads, and it's nowhere near what it claims to be. It's probably, at best, maybe 60 lumen. I wouldn't trust any of the *other* specs about it either, but they could actually be correct--you'd have to test them to be sure.

FWIW, a quick google for 60,000 lumen LED lights shows the *real* ones seem to typically require 450-500W of power (or more), and tend to cost in the nearly-$2000 range, and will be around the size of your torso, and weigh around 30lbs.

 

[zez3]

BTW, if it's really a 60,000 lumen light
So I suspect the ebay specs are lies, like many such ads, and it's nowhere near what it claims to be. It's probably, at best, maybe 60 lumen.

Clearly it's a lie. For sure not 60,000 but it is stronger than a beamer/projector which is rated 2000 lm.
I guess I need to get another wire in there