Re: Benq FP19G+ turns on and off randomly
I actually started typing that you're probably wrong because it was ok for tens of minutes and then without touchig it it would turn itself off and on.
Still, after replacing a random cap with a new one and turning it on but removing the buttons from the system it didn't do anything for quite some time.
You might just be right. Thank you
lion_sta
Member
Last Activity: 12-16-2016, 06:22 AM
Joined: 04-12-2016
Location: Chisinau
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Benq FP19G+ turns on and off randomly
Hello,
Like the title says this monitor started to turn itself on and off randmly.
It can work for 10 minutes or 30 minutes and then off, I can turn it on almost instantly.
The problem was worse before replacing a bulged capacitor.
Noticed that the main capacitor 450V/100uF was showing mostly 298V. Replaced it but the voltages stay the same.
The weird stuff is that even if I turn it off, it will turn itself on sooner or later.
It does the same without the backlights connected.
Thank you so much for... -
Re: Asus VH238 Shortcircuit
Fixed - bad soldering on my part.Leave a comment:
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Re: Asus VH238 Shortcircuit
Update 2.
Apparently it might have something to do with a connection.
If I have it in a certain position it works. Spin it a little and it's off.
How, I wonder would I find where the circuit breaks.Leave a comment:
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Re: Asus VH238 Shortcircuit
Update.
If I start the monitor without the screen attached, just the lower panel - then I have that light - on/off.
If I connect the monitor, there doesn't seem to be too much activity.
The big cap shows a reading of 295 which is weird.Leave a comment:
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Re: Asus VH238 Shortcircuit
Aaand I'm back.
Same monitor. Almost like someone unplugged it from the outlet. That was my first impression. I even turned around angrily looking who did that.
No sign of life.
So far checked until the big cap - it has 460 V.
Will try and keep on checking further.
If you know what might be the cause, please tell.
Thank youLeave a comment:
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Re: Asus VH238 Shortcircuit
Your knowledge and power of deduction on that resistance made it possible to fix another monitor.
After three months of waiting for those little pieces from China, managed to put it all together. Two for now.
Thank you to everyone who helped....Leave a comment:
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Re: Asus VH238 Shortcircuit
LD7575PS
104699
That'a what's written on that IC. If it wasn't broken before, I managed to that when desoldering. I will go to the market and try and find it.
How about that MOSFET
A 2761I
101 235
Is there any viable replacement?Leave a comment:
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Re: Asus VH238 Shortcircuit
Oh, no, we're not looking at the same IC. I was looking at the Inverter Transformer. That yellow thing. Was sure you said I should replace that. Sorry.
I will take a look at it tomorrow because it's at work.
Thank you.Leave a comment:
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Re: Asus VH238 Shortcircuit
Actually this is all that I could find on the IC:
SPW-205
SBI4 . 2 E156193
FEC 1110 A
Exactly like that. Unless there is something written on the bottom as I haven't desoldered it yet.
How about that MOSFET. Is there some replacement that I could maybe find easily?Leave a comment:
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Re: Asus VH238 Shortcircuit
Ok, I need your help guys.
I have the A 2761I MOSFET and the SMD IC - SPW-205 (SBI4 . 2 E156193 FEC 1110 A)
I cant find them both here, where I'm from. On Aliexpress I can find only the MOSFET.
Is there some alternative to these components?Leave a comment:
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Re: Asus VH238 Shortcircuit
I can't seem to find anywhere that IC.
Worst case scenario I will order the whole power board from Aliexpress.
But I will try to start it with the new mosfet and resistances.Leave a comment:
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Re: Asus VH238 Shortcircuit
Can that SMD IC be checked?
I am going to hate these resistances by the time I'm done with repairing. The other two are not too clear either. One of them shows no result. The other one shows something in the Mega Ohms.Leave a comment:
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Re: Asus VH238 Shortcircuit
Did that with the MOSFET out of circuit and the same thing. Very low resistance among all pins. Guess it's bad.Leave a comment:
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Re: Asus VH238 Shortcircuit
That resistance, that is also circled in the image, shows open circuit. No reading whatsoever.
Without removing the MOSFET from the circuit I get very low resistance between the S and D, G and D, and S and G.
I did check but wasn't sure what values I was supposed to have or which one was the ground pin. This is why I haven't put down the results. So not sure.Leave a comment:
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Re: Asus VH238 Shortcircuit
Wish I knew how you figured that out.
Thank you either way.
Do you mean I need to also replace the one I marked with one?...Leave a comment:
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Re: Asus VH238 Shortcircuit
How about that resistance, do you think I will mess it all up if I replace it with something not quite the same?Leave a comment:
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Re: Asus VH238 Shortcircuit
Right. If I remove it completely, would that do?
but first I'll check if it's actually faulty. Thanks.Leave a comment:
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Re: Asus VH238 Shortcircuit
Also, if I can't find this very resistance, what is the closest resistance that I can get away with?
50 Ohm I think would be too little?
100 Ohm, will it start at all?Leave a comment:
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Re: Asus VH238 Shortcircuit
I see. Will look for that resistance.
The audio part - not such a big deal.
Any of you have the service manual or the schematics of the board? I will want to know what voltages I need to have at the exits, where is the ground.Leave a comment:
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