Phillips 170B Screen goes Blank after 1-2 seconds

[thestigp11gt]

My current monitor is being a pain in the backside, as it takes about 20-30 hits to get the screen to come on. I was then given Phillips 170B monitor, however the monitor did sit in a shed for 4 years, which meant temperatures were down to -10*c and potentially dampness

Anyway I got it, let it get to room temperature (infact was about 3 metres from a radiator for a full day), I plugged it in, and the screen came on, for around 2 seconds and then went back off.

Done the usual search on Google, and suggested that the caps were probably done, The old caps were CapXon ones, There was no physical evidence that the caps were done as they were not leaking and were not bulging. I replaced the caps on the main power supply board anyway, plugged it up, exact same problem,

I am out of ideas not as Google is now limited.

[selldoor]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

boom, exact same problem,

Is the "boom" just for effect or did it happen? Did you have the correct
value caps and were they in the right way round.

I am out of ideas not as Google is now limited.

??

Perhaps repairs to your current monitor before it gives up completely
would be easier - sounds like the startup cap at the moment but it could get a lot worse. - Suggest start another thread for that.

Either way we are going to need really good clear in focus pictures you will need to take in good light and without flash.

[thestigp11gt]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

Is the "boom" just for effect or did it happen? Did you have the correct
value caps and were they in the right way round.



??

Perhaps repairs to your current monitor before it gives up completely
would be easier - sounds like the start-up cap at the moment but it could get a lot worse. - Suggest start another thread for that.

Either way we are going to need really good clear in focus pictures you will need to take in good light and without flash.

Ignore the part where i say boom, it's Scottish slang, i have a habit of forgetting to leave it out. I will start a new thread about the other monitor.

As I said the monitor goes off after 2 seconds, but what i have noticed is that the power LED remains on after the screen goes back off.

What I have also notices after trying to switch it on and off for about 10 times, when i did it once, there was a weird buzzing from the monitor, and then it went off once the screen went off again.

[selldoor]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

What is the part number on the power supply may be 715G1813-1 or something like that

[thestigp11gt]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

Model Number: EADP-43AF A

This is the PCB

[selldoor]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

Ok I will have a look at the pic though we normally require a straight down
and a pic of the back.
Here is a youtube video of someone diagnosing this board which has 2 sec to black.
I cant believe you could be so lucky!!
May just want to start at 20 minutes in.
If you have the voltages at the connector - think you will have - as otherwise it probably wouldnt flash at all you need not test most of the stuff - just th e inverter transformers for now.

http://www.youtube.com/watch?v=FYoS13Ox214

[thestigp11gt]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

Nice one, I need to order a new Tester, mine has went haywire, Will check it out as soon as it arrives.

[thestigp11gt]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

New tester arrived today, went though what that video did, but the inverters are fine, I have continuity though both of them

One thing i noticed is that one of the outputs which is for 12v, shows 13.5v when on power. Is this normal or is this the issue?

Just a note also, When connected to the power, and screen comes one, as i said you hear a funny noise (similar to the old snowy picture noise on old TV's but low volume) which happens for 2 seconds, Once the screen goes off it goes away.

When you turn off the monitor IE pressing the switch so the LED goes off, you can then hear a high pitch squeal, It is very faint, but goes off when you power on the device.

[Rtech]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

Just by chance I have a complete set of working boards for this monitor,although like a lot of monitors with the same model number the insides can be totally different.My lot include the PSU/Inverter 715G1813-2 and the Logic 715G1767-1 VB,the latter having a little plug in PC for the Audio.
I set it up on a Dell 17"Test Screen and it all works fine,BUT I did noticethat like yours the LED stays on Green as soon as the Power is connected, AND stays on irrespective of whether there is a PC signal or not,so I think yours is acting the same and is correct.As you do get a 'flash' of Screen initially,for the moment I suspect it is getting a PC signal,and what you need to do is eliminate the PSU/Inverter AND the Backlights !!.
On the Power supply connector that goes to the Logic board is there any markings to indicate what should be on each pin ???,and have you a set of test backlights from another monitor ??.I have added photos of my boards,and the same from you may be helpful !!

[thestigp11gt]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

The back light connectors are funnily enough the same as my Proview monitor, I wonder if I could use the power supply board to power the back light screen itself, to eliminate the actual back light being broken.

[Rtech]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

On the connector mentioned there may be a pin marked On or O/F or En(for enable),So if you connect ONLY your Psu to the mains,Plug in your screen backlights to the sockets and then apply 3v Dc(maybe from a battery) between the pin I have indicated and GND,or use a !K Resistor from the 5V which should also be on that connector, the lamps should work,if not then you have confirmed the fault is the PSU or backlight, then you can plug in the other set from the other monitor LAMPS ONLY and see if they work

[thestigp11gt]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

the 3.3vdc from a computer PSU will do the trick for that.

[thestigp11gt]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

Okay, So i built my Arduino Capacitance meter, One of the capacitors, which is the 100uf 450v one, shows as only 81uf - Could this just be another faulty cap?

[newtothis]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

What brand of caps did you use for replacements and which ones have you changed?

[thestigp11gt]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

I replaced all of them, All others seem okay

Unsure of the make, just has KXG on the capacitor.

[newtothis]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

I replaced all of them, all others seem ok.

So not all of them replaced???

Were they low ESR caps?

[thestigp11gt]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

Yes, All of them replaced, the capacitor in question is a KXG model, the other new capacitors are cheng.

Testing of other capacitors check out okay, the KXG model is the only one that seems out by a margin.

[budm]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

May be its time to use test lamps to verify the function of the inverter circuit.

[Rtech]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

I assumed he had done this from Post 11 ??

[budm]

Re: Phillips 170B Screen goes Blank after 1-2 seconds

I did not see if he indicated that he did or not after your post 11.
Post 10: "The back light connectors are funnily enough the same as my Proview monitor, I wonder if I could use the power supply board to power the back light screen itself, to eliminate the actual back light being broken"