Dmtech dml-4126

[sabre504]

HI all have a strange problem with this 26" lcd ,
when first start up all works fine all inputs work, menu's work and remote all fine until you turn it off then it stays in standby.

Tried a new PSU but still the same leave it unplugged for a couple of hours and it will work again but only till you turn it off.

Before i start delving into tests just wondered if anyone had come across this with one of these before or have any suggestions .

 

[fix2003]

tip
Check / Replace Regulator Q584 NCP1117DT18RK, CHS Part No.: NCP1117.
(RS Stock No. 518-8284      25 p each must buy 5)
also  Under the metal screening can on the video PCB. I replaced C1, this capacitor
was very hot (adjacent to Q584)

all the best
vince waterbeach

[sabre504]

Hi Vince  thanks for that wiil check those ,
was pondering the 4 pin regulator as well as it has the shut off pin but will try your suggestion first
 

[sabre504]

Hi Vince well i tested Q584 and the voltage reading was up and down as the tv is trying to start .

Q584 on mine is different from the one you  qouted and not near C1 ,so i started volt testing all the regulators but when i tested Q583 the tv started up ??

Thinking i may have shorted something i turned it off and then on again but the tv just cycled trying to start
pushed down on Q583 and again it started .

So either it has a bad solder joint or one of the tabs has a bad connection inside the plastic case so going to change that one first and see what happens 

[fix2003]

ACE
glad you got it sorted

[sabre504]

Hi well got it sorted .
After changing Q583 (crack in case) still not firing up so checked Q584 as FIXITNOW had suggested (Thanks Vince) and sure enough this was no longer putting out the correct voltage .
Sorted now thanks for the input