Benq Q7t4 / Fp71g+

[Bobdee]

Re: Benq Q7t4 / Fp71g+

Just a bit more. It is a big job to replace them. Look for blackend ends of the CCFLs (PHOTO'S ATTACHED). They must break through the glass. When they were replaced they are extreamly easy to break.

Sorry for posting in wrong forum. Did not realise there were others! But more the merrier.

Jamie

Hello Jamie
Thanks for both updates, had you not updated we would not have known the outcome
As for the wrong forum we all do it, once I posted in wrong thread LOL
Sometimes a moderator will put it in the proper place
I follow the monitor forum, only this thread is of intrest and I nearly missed it
Had you not updated yesterday I would have missed it all together (seen it in New Posts)
I am sure other members who follow the monitor forum would be interested in this thread, but would have missed it among the TVs threads, still never mind
Bob

[Senthil Kumar Krishnan]

Re: Benq Q7t4 / Fp71g+

I have this LCD moniter with few resitance burned out to black in the Power supply board. Is it possible for any one to post the circuit diagram or a picture of the power supply board.

-Senthil K

[retiredcaps]

Re: Benq Q7t4 / Fp71g+

I have this LCD moniter with few resitance burned out to black in the Power supply board. Is it possible for any one to post the circuit diagram or a picture of the power supply board.

-Senthil K

Lucky for you this FP71G+ is sitting right on my desk and it is a sunny day out today.

[mbates14]

Re: Benq Q7t4 / Fp71g+

yup. those CCFL lamps are a big issue.

I had to replace them in several LCD monitors.

if the cathodes are not pulling the proper current the inverter will shut down. most power supplys have a PROTECT line now. when the inverter shuts down, it toggles PROTECT which may/may not go back to the CPU. but it DOES shut the main supply back into standby on various power supplies.

ive seen this in a few newer dell monitors and various others. but not viewsonics.

[retiredcaps]

Re: Benq Q7t4 / Fp71g+

yup. those CCFL lamps are a big issue.

I had to replace them in several LCD monitors.

if the cathodes are not pulling the proper current the inverter will shut down. most power supplys have a PROTECT line now. when the inverter shuts down, it toggles PROTECT which may/may not go back to the CPU. but it DOES shut the main supply back into standby on various power supplies.

ive seen this in a few newer dell monitors and various others. but not viewsonics.

I think this reply is meant for a different thread? If yes, please post it as it is valuable feedback.

[mbates14]

Re: Benq Q7t4 / Fp71g+

its in reply to this thread. but its just "general info" as needed fit. just throwing my 2 cents in on the CCFL issue.

[badrianiulian]

Re: Benq Q7t4 / Fp71g+

Hy
Anyone knows the value/markings of Q2 on this display M170EP01 V2 ?
Mine is kind of burned
Thanks

[selldoor]

Re: Benq Q7t4 / Fp71g+

Think its a 2N3906 same as Q3 ?

[badrianiulian]

Re: Benq Q7t4 / Fp71g+

Think its a 2N3906 same as Q3 ?

Well, I was thinking the same, but I replaced it with the same value as Q3 and also replaced power smd fuse and all it shows now is a blank white screen.
So I'm thinking it might be some MOSFET trasistor

[selldoor]

Re: Benq Q7t4 / Fp71g+

If you need more help we will need more details and photos.
Tell us what it does from the moment it is plugged in to getting the white screen.
What does the power light do - any sounds - clicks hiss screech.
You should have it all connected up and a known working input from a pc.

Please post good clear pictures pictures of each board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246

I dont know if you have the SM - it is here

http://www.eserviceinfo.com/download...7T4-FP71G.html