HP w1907 2007.01.15 ILP1-027 troubleshooting

[jlum1951]

I've been struggling to find a schematic for a pesky HP w1907 monitor. Sometimes it flickers, sometimes it reverts to a 2 seconds to black. I have opened it up more times than I care to remember, reflowed solder, or switched lamps around and it magically may seem fine, then I put it back together and it will misbehave again. Some have replaced lamps but this can all the lamps suddenly go bad?

The power board marked as 2007.01.15 ILP1-027. It seems there are schematics for the later versions but they seem to be totally different. One thing I want to bring to the attention of this forum for those with the named power board is the datasheet for the IC501 Inverter Controller that is surface mounted to the back of the power board. This device is responsible for soft-start powering on the lamps, dimming, as well as shutting down the lamps in case of an OVP fault or open lamp protection. In other words, everything downstream of IC501 is slaved to it. The datasheet also includes a simplified application circuit which has been very helpful. The datasheet is attached.

But if anyone has a real schematic for this monitor with the above named power board, please post. Thanks.