Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

[imalearner]

My neighbour has got wind that I know all about computers?

See what happens when you do one nice person a favour, (defrag their hard drive or summat like that), then they talk to one of the other neighbours....the biggest gossip in the world!!!

So now I have my neighbours Viewsonic VA 1616W -2 LCD monitor. No Lights at all. Symptoms he described were that it was beginning to play up, sometimes coming on, sometimes not......so it's going in the bin....unless the "man who knows all about computers", can save it.

So everyone, no pressure here...would anyone like to suggest where I start, point by point. Please use this photograph, hope it's good enough, to pin- point parts to be investigated, replaced etc.

Hope someone can help, and thanks in advance.

Imalearner

[imalearner]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

I have simply checked for bulging on main caps, dry joints on board. I've a bog standard digital meter, and component testing is something I know almost zero about.

[Rtech]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

The first step then is to measure the Voltage across the large cap,dependant where you are in this wonderful world, it should be about 165VDC for those that have 110 AC volts mains,and 325VDC for those with 240 volts mains.If that looks Ok, then the pins on the right hand side of the board, is there a legend saying what they should be or just pin numbers ???

[imalearner]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

The first step then is to measure the Voltage across the large ... it should be ....325VDC for those with 240 volts mains.
???

Thanks for such a quick response!

I find myself in Wales at 240Volts + or - %10

Now please feel free to call me stupid but what you have said means...

Connect to power source.

Set range on multimeter > than 240V (because we're expecting a reading much higher yeah?), so in my case that's 700. I have only two choices 200 or 700.

Touch negative lead on meter to striped side on large cap, and positive lead to other.......take reading?

Take reading.....


So I did and it's a wavering result between 735V and 741V !

Unless I am doing something very wrong, could this be a confrimation that at least this component is frizzled? There is no sign of any bulge top or bottom.


And.....for my edification, where you ask for a "ledgend" to do with the pins to the side of the board, am I looking for a part number or an indication as to which pins go where?

Thanks,

imalearner

[tron]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

cap After rectifier = DC (Direct Current)

You measured in AC range?

if digital meter, then you can
put the leads the other way
too, polarity is indicated
as a minus on
the screen

[Rtech]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

There is obviously a problem with your measurement as tron pointed out,it is not possible to read that high a voltage.A legend near pins like yours is sometimes printed on the Board and indicates voltage, On/Off, Dim/brightness etc etc.

[imalearner]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

tron and Rtech, my apologies!

I have measured the AC Range by mistake. How embarrassing is that?

However, now that I know that, I have rechecked, and I am getting a stable reading of 335VDC

Mains Voltage is presently 244V

So, moving on, the reading I have got is a little higher than Rtech suggests it should be so I'm wondering what next?

I have checked for ledgends and any other info printed on the board, but nothing stands out as you have described it might. Would a closer picture(s) help, and if so which parts would it be helpful to you to have close ups of?

Grateful for any further next steps.....

Imalearner.

[PlainBill]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

tron and Rtech, my apologies!

I have measured the AC Range by mistake. How embarrassing is that?

However, now that I know that, I have rechecked, and I am getting a stable reading of 335VDC

Mains Voltage is presently 244V

So, moving on, the reading I have got is a little higher than Rtech suggests it should be so I'm wondering what next?

I have checked for ledgends and any other info printed on the board, but nothing stands out as you have described it might. Would a closer picture(s) help, and if so which parts would it be helpful to you to have close ups of?

Grateful for any further next steps.....

Imalearner.

The first picture is excellent - sharp and detailed enough I can identify components. I would like to see a picture of the bottom side of the board. We can see which points to check from that. It is easiest if you lay the board in the same position as the first picture, then flip it over left to right. That way I can easily establish a point to point relationship between the top and bottom views.

PlainBill

[imalearner]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

I would like to see a picture of the bottom side of the board. We can see which points to check from that. It is easiest if you lay the board in the same position as the first picture, then flip it over left to right. That way I can easily establish a point to point relationship between the top and bottom views.

PlainBill

Thanks on that Plainbill (still using the last monitor you helped me with).

Here is photograph of reverse side Viewsonic VA1616W -2 as requested. My cheapo camera has a little pin cushion at close range, but I think you can see what's what?

Cheers

Imalearner

[Rtech]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

JUst above the pins on the side of the Board is link J35, this is ground,At the bottom of the set of pins is a Fuse,have you checked that ?????If that is ok then with the meter on Dc Volts, put the Black probe on the j35 and measure the voltage on the pins,and advise.

[PlainBill]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

a VERY minimalist design. What is the part number of U1 on the bottom side of the board?

PlainBill

[imalearner]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

JUst above the pins on the side of the Board is link J35, this is ground,At the bottom of the set of pins is a Fuse,have you checked that ?????If that is ok then with the meter on Dc Volts, put the Black probe on the j35 and measure the voltage on the pins,and advise.

Fuse checks out okay..

Photograph shows pin arrangement in close up. I have blobbed them with colours...Black probe on the J35 and measured..

Red = 2.39 to 2.59

Green = 2.39 to 2.59

Blue = 2.31 to 2.57

All other pins obtain no reading.

Thanks,

Imalearner

[imalearner]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

a VERY minimalist design. What is the part number of U1 on the bottom side of the board?

PlainBill

Minimalist...that's what I thought too, even though I do not know much about anything yet - I have just taken things apart for the fun of it.

I can only see one part with a prefix 'U' Plainbill, and thats U31 ( I call this the top of the board.....is that the part you mean please.

Thanks,

Imalearner

[Rtech]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

Well trying to follow part of the circuit,the voltages all seem to be from interconnected pins ??, and they should be at leat 5V,as that is normally what the Logic board uses.So, it looks as though the 5v is derived from D32,so that needs testing with the diode test settong on your meter,if you have one ???if not use the resistance range,also the two caps near those should be checked and changed to see if they are the cause.It is also possible that the reason for the low voltage is due to a problem in the inverter side.D31 looks l;ike it produces 12v for the inverter.and it looks like FS51,J32 and J33 take that voltage up to the inverter circut,so if that is the case,and you will have to trace it from D31,then lifting one end of them and then checking the 5V again,may help to indicate where the problem is ,and the part code of Q54 on the bottom of the Board is maybe what Bill wants !!

[PlainBill]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

Minimalist...that's what I thought too, even though I do not know much about anything yet - I have just taken things apart for the fun of it.

I can only see one part with a prefix 'U' Plainbill, and thats U31 ( I call this the top of the board.....is that the part you mean please.

Thanks,

Imalearner

U1 appears to be the SMPS controller. It's the 6 pin IC circled in yellow on the attached picture.

PlainBill

[imalearner]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

U1 appears to be the SMPS controller. It's the 6 pin IC circled in yellow on the attached picture.

PlainBill

Wowee, I found U1 - that's a very small component to read - found my glasses - and now when I look on the back of the board it feels like I am on another planet.

The 6 pin component is very poorly marked. It appears to have a trademark - a capital getter G in a square.

Then from what I can make out, it looks like JP 35 (but the letter J is neither capitalised or lower case). It's very thinly scribed - and I am best guessing what the charcters actually are, considering what there is to see. Hopefully, what I've noted might be enough?

Photo is for confirmation that we are on the same component.

Cheers,

Imalearner

[imalearner]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

Well trying to follow part of the circuit,the voltages all seem to be from interconnected pins ??, and they should be at leat 5V,as that is normally what the Logic board uses.So, it looks as though the 5v is derived from D32,so that needs testing with the diode test settong on your meter,if you have one ???if not use the resistance range,also the two caps near those should be checked and changed to see if they are the cause.It is also possible that the reason for the low voltage is due to a problem in the inverter side.D31 looks l;ike it produces 12v for the inverter.and it looks like FS51,J32 and J33 take that voltage up to the inverter circut,so if that is the case,and you will have to trace it from D31,then lifting one end of them and then checking the 5V again,may help to indicate where the problem is ,and the part code of Q54 on the bottom of the Board is maybe what Bill wants !!

Here's the meter at my disposal - thanks for all flying lessons on how to use it properly - I'm wondering again ...should I be removing each component for testing? The reason I ask is because there seems to be quite some conflicting info about the net in general, some say complete removal, some say no need - but since I am asking here for some help - I want to 'do it right', your way?

Thanks

Imalearner

[PlainBill]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

Wowee, I found U1 - that's a very small component to read - found my glasses - and now when I look on the back of the board it feels like I am on another planet.

The 6 pin component is very poorly marked. It appears to have a trademark - a capital getter G in a square.

Then from what I can make out, it looks like JP 35 (but the letter J is neither capitalised or lower case). It's very thinly scribed - and I am best guessing what the charcters actually are, considering what there is to see. Hopefully, what I've noted might be enough?

Photo is for confirmation that we are on the same component.

Cheers,

Imalearner

Well, that's the right part, but the markings don't seem to appear on any cross reference list. I'd have to say that following Rtech's suggestions is more likely to produce results. The SMTP controller IS working; the output voltage is too low, which would point to either an excessive load or a bad component other than the controller.

PlainBill

[Rtech]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

Here's the meter at my disposal - thanks for all flying lessons on how to use it properly - I'm wondering again ...should I be removing each component for testing? The reason I ask is because there seems to be quite some conflicting info about the net in general, some say complete removal, some say no need - but since I am asking here for some help - I want to 'do it right', your way?

Thanks

Imalearner

On the meter it is the setting between 200 and HFE.With the black on the end of the diode where the 'white band' is and the red on the other end you should read between approx .3 to .5, that is the voltage drop...turn the lead around and the reading shoud be infinity.You can aslo do the same on D31.

[imalearner]

Re: Viewsonic VA1616W Non Starter, No Lights, Suggestions Please!

On the meter it is the setting between 200 and HFE.With the black on the end of the diode where the 'white band' is and the red on the other end you should read between approx .3 to .5, that is the voltage drop...turn the lead around and the reading shoud be infinity.You can aslo do the same on D31.

Thankyou. Please don't mind me being so methodical (some might call it slow) but it's the only way it sinks in.

So, how my doing...and am I doing it right?

Photographs attached, and the diode tested is marked D79 SR360

Cheers
Imalearner

P.s. D31 is reading 404 in circuit ( and 1 when reverse tested - like the others) To I.D. it, I would have to remove it as it's squashed with what looks like chewing gum -something to keep it stable on the board no doubt.