Acer AL1917 restarting

[Behemot]

Re: Acer AL1917 restarting

Immediatelly as I plug in power cord.

Didn't measure voltage on input cap, but on the outputs everything was smooth (having just the power board alone, data board and CCFL unplugged).

[retiredcaps]

Re: Acer AL1917 restarting

Just curious, what voltages do you get across the

1) big filter cap? Is it stable?
2) little startup cap? Is it stable?
3) 5V SB?

when the problem happens?

[Behemot]

Re: Acer AL1917 restarting

I can open one display I repaired recently. Maybe will take photos than too :-D For a quick try (connecting it from the second display directly into this firsts inverter) that should not be a problem…

[senndogg]

Re: Acer AL1917 restarting

do you have spare ccfls, just for a try? You know that if the ccfls are aging they drain much power, maybe this puts the system in a restart loop.

[Behemot]

When I first got it, it didn't work at all - blown rectifier and fuse on primary side. After replacing them I just fired it on for a couple seconds, seemed good.

Than I recapped it just for sure (full of Taicon and CapXon), now, when everything is connected, the display powers of for a fraction of seconds, than off and on again over and over. Unpluging CCFL stops this behaviour, I see image using flashlight. Changing all the caps on inverter power supply (various 25V caps, there is up to 24 V on it) back did not help.

This leads me to bad lamp, do you think it's possible? If it was shorted transformer or transistors on inverter side, I think it would not power on at all even without CCFLs connected.