Re: HP ENVY all-in-one 27 b208na screen dark one side
I have added a photo of the display. It started in the bottom left corner then spread to the whole left side.
What is the most likely cause?...
FitPaul
Member
Last Activity: 11-01-2022, 04:07 AM
Joined: 01-21-2018
Location: London, UK
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HP ENVY all-in-one 27 b208na screen dark one side
I have a HP ENVY all-in-one 27 b208na with the screen dark on one side. I expect it's due to a faulty back light or inverter on that side.
My question is where is the inverter located? In the base or behind the display. How do I dismantle the display to check the backlights? I tried to take off the back cover but it cannot be removed completely so does not give good access to the display. Should I gain access to the display from the front? -
Re: Philips 170B4 BB/02 flashes on for a split second
Thanks RJ, budm. I know a new monitor is very cheap these days but I'm frustrated that I can't fix this one. You know what it's like. I've already learned SO much.
I'm now pretty sure the problem is with the inverter.
There are four ccfl lamps in the monitor. I have used a two lamp inverter that I had lying around to test all combinations of the four ccfls, two at a time. Every combination works and draws 0.6amp in the low voltage supply of the inverter. I tried substituting the T5 4watt...Leave a comment:
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Re: Philips 170B4 BB/02 flashes on for a split second
Ok I'll do that tomorrow and get back to you.
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Re: Philips 170B4 BB/02 flashes on for a split second
Thank you RJ. Should I put an amp meter in circuit and check all the ccfls again? See if they all draw the same current?Leave a comment:
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Re: Philips 170B4 BB/02 flashes on for a split second
Thank you all for your advice and suggestions.
Rddube, The circuit diagram RJ has posted looks like mine. It shows 3.3v on pins 1&2 and 12v on pin 7. There is no 5v. The pictures I posted earlier are of my actual board.
Dumah Brazorf: As far as I can tell, all four ccfls look the same when they light up. I got this tester on ebay.
[url]http://www.ebay.co.uk/itm/132427753417[/url]
The winding resistance of the two inverter transformers is the same. I reheated the solder points...Leave a comment:
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Re: Philips 170B4 BB/02 flashes on for a split second
I do have 12v on pin 7 and 3.3v on pin 1-2. Pin 4-5 have 0v and don't seem to be physically connected to anything. So presumably I only have 3.3 and 12v. Pin 12 gives 3.3v. I checked all the ccfls with an inverter I bought on ebay and they all light up with the same intensity.Leave a comment:
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Re: Philips 170B4 BB/02 flashes on for a split second
Thanks for your message. Like I said, the circuit diagram I found is not 100% correct for this monitor. I don't have IC7001 or any of the circuitry around it. The caps were all new electrolytics but I didn't check them before I installed them. I will check again that installed them the right way.Leave a comment:
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Re: Philips 170B4 BB/02 flashes on for a split second
JPG shows where I measured voltages...Leave a comment:
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Re: Philips 170B4 BB/02 flashes on for a split second
Pictures and circuit diagram I found attached.
Just found out how to attach a file...
Last edited by FitPaul; 02-10-2018, 10:59 AM.Leave a comment:
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Philips 170B4 BB/02 flashes on for a split second
I have been trying to fix a Philips/LG 170B4 BB/02 monitor and I need your help. Initially, it just wouldn't stay on with the power light off. I took it apart and changed all the electrolytic caps (some were bulging and some were leaking). Now when I turn on the monitor it flashes the display for a split second before going black. The power light now stays on now.
I found a circuit diagram on the internet but although it's mostly the same, some areas are different. The circuit diagram shows three voltages 3.3, 5 and 12v but on measuring, my monitor only seems to have two (3.8v and...Last edited by FitPaul; 02-10-2018, 10:11 AM. -
Re: New Members - please post your introductions here
Hi Guys,
I have been interested in electronics as long as I can remember. My dad who was a pathologist was always tinkering with electronic stuff. I remember him fixing neighbours amplifiers and radios and building Heathkits (remember them?). It must have rubbed off on me because when I was 8 and was asked what I wanted to be, I answered ‘a radioman'.
Well I never became a ‘radioman' but now age 64 I'm an anesthesiologist but still enjoy electronics as a hobby. I lament how hard it is to fix things these...Leave a comment:
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