Proview 17 inch lcd monitor model #700P

[kc8adu]

Re: Proview 17 inch lcd monitor model #700P

http://www.aosmd.com/web/products/pr...tnumber=AO4606

[smoresh]

Re: Proview 17 inch lcd monitor model #700P

shirt=short, sorry, keyboard mistake. Yes, it didn't work at all, fluke 75 meter.
measured short d to s on u101, .3-.4 ohms, that explained 7815 not function. R17 measured 5-6 ohm, as sleeved, unable to proof correctness.
according AO 4620 replaces 4606. the point now is living in GMT+2 area, it's difficult to get parts. Thanks

[smoresh]

Re: Proview 17 inch lcd monitor model #700P

found U101 shorted bn d to s both, probably there was an electrical problem on the site that caused a spike, and the screen didn't lit the power led. found AO recommends 4620 instead. living in GMT+2 area, I have difficulties in getting this part.
Thanks for the site, helping very much.

[johnboy183]

Re: Proview 17 inch lcd monitor model #700P

I have been working on one of these monitors in recent days with the typical symptoms of 2-3 seconds then black but it had no capacitor problems and everything else checked out fine. In desperation I disconnected one ccfl and then the other and found that one flashed up for the two seconds far brighter than the other (however it also did the same if I connected another good screen as well ruling out the ccfls). I then began swapping components over from the "good" side to the "bad" and the sypmtom remained the same until I swapped the two transformers over an lo and behold the bright ccfl became the dim one and vice versa. I had never tried this before but certainly will again as it is a way of identifying components for those of us more in the DIY world without the sophisticated tools of those who mend monitors for a living and not for a hobby like myself.
Of course now I am left with the problem of trying to find a suitable transformer. I have many salvaged inverters but none with the identical transformer (markings are P0316 PD206 and its physical type can be seen in the 700p photos elsewhere in this thread).
Anyone know if there are data sheets available for such components and/or equivalents charts and where I might access them? Shame to get to the point of having found the fault without being able to do a fix.
Many thanks
Johnboy183

[ecking767]

Re: Proview 17 inch lcd monitor model #700P

it had no capacitor problems and everything else checked out fine.

How did you check the caps? The Proview power supply in your model monitor is known for having bad caps even if they are not swallowing.

Also what is the part number for the output transistor?

[johnboy183]

Re: Proview 17 inch lcd monitor model #700P

Hi,
I checked the caps with my PG015 cap tester and even though they read fine I replaced them all anyway.
I am not sure why you are asking about the transistors as I have eliminated them by what I described above I thought (ie if I could move the fault by what I did from one inverter circuit to the other then surely the transistors cant be involved - only the faulty transformer). Am I missing something as if I am I would be very keen to know so I dont go down the wrong route?.
Many thanks
Johnboy183

[ecking767]

Re: Proview 17 inch lcd monitor model #700P

I am not sure why you are asking about the transistors

I have see three types of power supply & inverter board for your model LCD monitor:

first having only two out transistor: D444
second having : AO4606 four of them
third having P2103NV four of them.

since you haven't posted any picture I needed to know which board you have.
the second and third with the four output transistors are known to fail in time.

Did you replaced the two cap near the output transistor? its should be 100uF or 150uF

[johnboy183]

Re: Proview 17 inch lcd monitor model #700P

Hi,
I understand what you mean now about the 3 boards but as I said in my first post the board (and the transformers and transistors) are exactly as per the one shown at the start of this thread top and bottom of board. The transistors are 4 x AO4606 (I assume you mean the ones at U101 U102 U104 and U105). They are unburnt (first things I checked when I saw others had had those problems. Yes the two caps next to them have been changed.
I would have thought U101 and U105 control one transformer and U102 and U104 the other (unless someone tells me different) so if I have swapped the two transformers to each others place in the circuit and the fault moves with the transformer then I fail to understand why the transistors should make any difference and as the two caps were changed and are balanced in output which I realise is critical with this set up then surely I have a failed transformer.
All I was asking is whether such transformers can be substituted by others of a similar type and how may I find out which (at least I think that is what I asked).
Cheers
Johnboy183

[ecking767]

Re: Proview 17 inch lcd monitor model #700P

remove both transformers from the circuit board and measure both primary and secondary and post the reading. this will confirm if one of the two are truly bad.

[PlainBill]

Re: Proview 17 inch lcd monitor model #700P

remove both transformers from the circuit board and measure both primary and secondary and post the reading. this will confirm if one of the two are truly bad.

This may or not prove it to your satisfaction. Depending on the nature of the flaw, there may be little difference in resistance.

The troubleshooting johnboy has done demonstrates clearly that one transformer is defective. The only more definitive test requires a ring tester.

PlainBill

[Alan123]

Re: Proview 17 inch lcd monitor model #700P

Same monitor - Proview 17 inch lcd 700p . Got it used for free, and used it daily as a second monitor for over two years. Occasionally has some minor wiggling. interference (likely the capacitor going or something similar)
Suddenly, my power went out, not lights at all, no power light. My capacitors all looked good EXCEPT the big one that is not included in the kits - 100ufd 450v for 105 degrees. (online they say they rarely fail.) Well, mine did. It was bulging on the top and has some leakage near the bottom wire. Researching it brought me to this great site. Ordered a new one online from DigiKey, will see if this will this fixes the issue. Also, the rectifier (?) attached to the Aluminum Heat Sink does not seem to have a good solder to the board. (The triangle of 3 solder points, surrounding the center cut out on the bottom of the board, near C001). I will clean and reflow those as well when I do the repair.

[Rtech]

Re: Proview 17 inch lcd monitor model #700P

Have seen these with ALL caps bulged,and occasionally the big one as well.Normally the caps near to the inverter transformers also are regular failures BUT always look good.