Ca$io XJ-V10X (10pcs NUBM47-A1) Current Readings

[loreadarkshade]

I've scored another XJ-V10X from ebay, which contains 10pcs NUBM47-A1. It was only $61 USD after taxes and shipping!
This unit was so cheap because it did not power on. I replaced the DMD circuit board and chip and it fired right up! The main menu indicated only 16 hours of runtime! Wow!

Before extracting them, I was curious how hard they drive these diodes, so I measured them with the projector opened and running.
Here are my results:

XJ-V10X - Clamp Ammeter
Prod. Date: 2019/11
Power saving level amperages:
7: 0.94A (max power savings)
6: 1.07A
5: 1.20A
4: 1.33A
3: 1.46A
2: 1.59A
1: 1.72A
Full Power: 2.16A

I also measured across this shunt resistor marked R033, meaning it is a 0.033 ohms resistor.
The voltage across it was 71.6mV at full power. Using ohm's law, we can calculate 2.16A at full power, which is exactly what my ammeter measured.



Thought you guys might find this interesting!

 

[Gryphon]

Great find and good job getting thing powered back on. I knew they would have been driving these diodes low for long life but I didn't think it would have been that low.

 

[RedCowboy]

IINM as the diodes age along their 20K hour MTTF or rather their mean time to half brightness, the projector will increase the current to compensate, this is one reason these diodes have so much headroom, I expect a high hour projector will drive the diodes at up to 3-3.5A

 

[loreadarkshade]

XJ-V2 also runs their 8pcs NUBM44-81 diodes at 2.22A at full power