Infocus X10 ballast bypass

[jeevs]

Hi All,
I am trying to bypass the ballast on an InFocus X10 projector. So far no success as it shuts down after the initial sequence. Here are the steps I tried.

The control cable is of 5 wire. The voltages with no lamp and boot up are as below
+3.2
0
+5
0
+5

The voltages with lamp in and bootup are below
+0.2
0
+5
+3.2 when lamp is warming up and +4.17 when lamp is warmed up and displaying image. +4.2 on power down.
+5

I grounded the +3.2 wire and used a variable resistor to supply 4.17 to the 4th pin taking power from the +5 pin but still it shuts down a fraction of a second after the bootup sequence.
I thought it is missing a lamp source so put a 100W led complete with heat sink, lens and all but still same behavior.
The 4.17v wire does not show a constant voltage in my digital multimeter but it varies 4.17 to 4.18. Whereas +5 remains a constant 5.
I think its a signal and not just a constant voltage. I am stuck on how to figure out if it is a signal and how to bypass it.

Below is the make and model of what is written on the ballast
EUC 300c P/11
9137 008 91969

The online doc in the link below is of 260d maybe the older version of the ballast, but looks and wiring is quite similar

°Ù¶ÈÎÄ¿â--ÄúµÄ·ÃÎʳö´íÁË ... 93931.html

Please, anyone share some info if this bypass can be achieved.

Thanks.

 

[bobegnops]

ballast bypass

no luck so far ?


I have the same ballast - still looking

 

[abradatanu]

I know this is an old thread but it might help others

Look at the attached image and find the 3 optocouplers on your power supply board in your projector and you'll see that one of them will be facing the oposite way. Solder its feet as shown in the image and it should bypass the lamp.

I've tried this with 3 projectors so far and they all worked