ADI Microscan A707 & BenQ FP731 LCD's

[Norm_au]

Hi All,
I have an annoying issue with a ADI monitor I have, I turn it on it boots up then 20 to 30 seconds latter it goes black, the led is still green but no monitor, turn it of then on, same deal, I have looked at the boards in it for a dry solder or a dead diode or a rounded pot, but nothing that catches my eye, I hope I'm in the right place for this post, and let me say what an impressive forum you lot have here, going to be a great help for future situations I can see that, ( I like playing with things that stop lol )


I also have a BenQ FP731, model Q-7T3, it just stopped one day for no reason, I thought it might be the fuse in it "T2A H250V" I took it out tonight to see if it is any good, need to get a multi meter tomorrow, any sort of a heads up with this would be greatly appreciated as well. thank you in advance and much Peace to you all.

[EGuevarae]

Re: ADI Microscan A707 & BenQ FP731 LCD's

Welcome yo the forums. As always, pictures would help.

[Norm_au]

Re: ADI Microscan A707 & BenQ FP731 LCD's

Hi eguevarae, thanks for the welcome and reply, here are some images, the ADI one, I could be wrong and no dought am, but I think the small board to the right could be my trouble, and of course there is the BenQ I replaced the fuse today I couldn't get the ceramic one so I just got the glass one, any way still only getting the green led to say it is on but black screen, I hope these pics are what you were asking for, if not please let me know. Peace

[EGuevarae]

Re: ADI Microscan A707 & BenQ FP731 LCD's

Hi eguevarae, thanks for the welcome and reply, here are some images, the ADI one, I could be wrong and no dought am, but I think the small board to the right could be my trouble, and of course there is the BenQ I replaced the fuse today I couldn't get the ceramic one so I just got the glass one, any way still only getting the green led to say it is on but black screen, I hope these pics are what you were asking for, if not please let me know. Peace

Right. The right side board is the inverter (ADI). What brand/series/rating are the two caps at the inverter's input? I fixed a similar inverter changing the caps for two Nichicons 150uf 16v. The monitor just flickered a lot, and after a while it just turned off. After the recap, no problems , and it has been working 24/7 for a month.
As for the BenQ, you should check the 5707s, check the fuse at the inverter's section input, and resolder all the transformer's pins as a start. I can't see any bulged cap on the pics. If you post the info on them, someone will jump in with a replacement suggestion in no time.
There's a great thread in the forum for the Q7T3/4 around. I think the credit goes to Davmax for that one.

[Norm_au]

Re: ADI Microscan A707 & BenQ FP731 LCD's

ok, first the ADI here is all the markings from the two caps [105 degree c] temp it can go to I guess, then [M2026] [EVL] [NKcon] [56UF] [25V] I looked on the BenQ board and could find nothing even close to 5707 or F707, and are the two square box's either side of the brass coil block the fuses you talk of ?. thx for your help.

[EGuevarae]

Re: ADI Microscan A707 & BenQ FP731 LCD's

ok, first the ADI here is all the markings from the two caps [105 degree c] temp it can go to I guess, then [M2026] [EVL] [NKcon] [56UF] [25V] I looked on the BenQ board and could find nothing even close to 5707 or F707, and are the two square box's either side of the brass coil block the fuses you talk of ?. thx for your help.

5707 is the part no. of the transistors that drive the transformers.
Look at the picture (is a bigger/better picture of your board). Green ones are the 5707. Blue ones are something you should check too. And yellow is the picofuse you must see if it is open or not.

[Norm_au]

Re: ADI Microscan A707 & BenQ FP731 LCD's

Hi eguevarae,Thanks for the picture and heads up on what to look for, I'm very new to all of this and appreciate your patience and your time, I will get all of the said items you shown me latter today and replace them all I got to get a result out of that lol, and do you think I should replace those two caps on the ADI board ? might as well it can't hurt right ?. Peace