On 07/02/2014 18:08, N_Cook wrote:
On 07/02/2014 16:53, 2phar wrote:
Hi all..

I have a BENQ G2420HD 24" LCD monitor.

Display backlight seems good, etc. But unit shuts down completely after
about 20-30 mins (no backlight, power LED goes out). Holding down power
switch at this point will cause unit to come back up after about 30-40
seconds. Then it will die again within 5-10 mins, but can be restarted
the same way.

I've already replaced all the elect caps on the power supply board.

Is the power board still the most likely problem here? Any suggestions
as to how to pinpoint the cause would be most welcome.

IR thermometer, targetted narrow jet freezer spray or hot air through na
silicone tube

OK..
to follow up, I ran the unit on the bench and monitored temps with IR
thermometer. Nothing on the PSU board really got more than slightly warm
(under 40C), but the main ASIC (Realtek RTD24282RD) on the controller
board really warms up.. it gets to around 70C before monitor shut down
after 10-15 mins. I bent a piece of aluminum and applied it to the
surface of the IC with some heat transfer compound, and the monitor then
seemed to stay in operation much longer.. over an hour. Eventually shut
off, but on restarting it again stays on for a long time, rather than
less than a minute.

None of the other components are getting as warm.. 50-60C max. One of two
22uF elect caps on the board (near the connector from the power supply
board) is getting warm but not hot.

Could the ASIC develop an overheating issue by itself, or would something
else be more likely?