Samsung T260 turns off and on by itself

[bammbammfran]

Re: Samsung T260 turns off and on by itself

the chip gets 3.3 volts through the one pin from the power board plug, so if the voltage is too high it can overheat.
it may also have loose solder joints which can do the same thing on this type of chip with solder being under the chip.
so , testing the 3.3volts is the first thing to do.

[diegus]

Re: Samsung T260 turns off and on by itself

Finally got time to measure the tensions, in both the larger connector that goes from the power to the logic board and in the small connector that goes to the touch button, here they are:

Monitor on (just plug in)

• PWR-DIM: 5,05
  15.0V: 15,22
  GND: 0
  5,2V: 5,26~5,27 (both of them)
  A-DIM: 0,86
  ON/OFF: 4,51
  3.3V: 3,30
  LED: 2,95
  KEY1: 3,05
  KEY2: 3,29

With the monitor turned off properly:

• PWR-DIM: 0
  15.0V: 15,33
  GND: 0
  5,2V: 5,26~5,27 (both of them)
  A-DIM: 0
  ON/OFF: 0
  3.3V: 3,28
  LED: 0
  KEY1: 0,15
  KEY2: 0

I applied heat one more time to the touch button, after a few seconds it went off and I measured again, tensions were the same as when I turn it off myself.

I'm not going to try removing the touch button board anymore since I can't risk breaking it, but I'm going to try isolating it somehow from the heat that comes from the nearest lamp.

I also tried heating up the other side of the lamp just to see if I was inadvertently applying heat to it instead of the touch board but after 30 secs. it didn't fail.

Does anyone know how the PWR-DIM, A-DIM and ON/OFF pins work? Would it be possible to bypass the touch button to keep the monitor on perhaps?

[bammbammfran]

Re: Samsung T260 turns off and on by itself

running 5 volts to the on/off pin at the power supply would turn the power supply on and may in turn fire it up
I am not sure why you have a pwm dim and an A dim ? and if those will turn on once the power supply gets turned on. usually I find that the dim pin in always on
try to see if one of those two voltages go up or down as you adjust the brightness.

3.3 to the power button board looks good
I am surprised to see 3 volts on both key1 and key 2 (I would have thought that these were going to be in millivolts)

[diegus]

Re: Samsung T260 turns off and on by itself

Hi. Sorry for the lack of updates.

A lot of work came in so I had to put the monitor back together on Saturday and could not do any further measurements, but I will certainly keep this discussion for future reference.

I put two small layers of mica insulator (the kind that you find inside hair driers) between the touch button board and the lamp housing.

So far it hasn't failed again after many hours of work during several days.

My sincere thanks all for your help.

[bammbammfran]

Re: Samsung T260 turns off and on by itself

looks like yet another design flaw !!
Good to hear it works

[Maverick Wolfe]

Re: Samsung T260 turns off and on by itself

Awesome at least you found a quick temporary Long term fix for this until you can get it completely repaired! Good to Hear!