Does anyone own a DELL E153FPf lcd/tft monitor ?

[Vipersan]

Hi friends ..
I have one of these on my bench for repair ..and have already done most of the work to repair it ..
I've searched the internet for days ..but cannot find a schematic ..ealier versions such as E153FPc ..yes ...but these used single sided pcb and mostly discrete components ..
However...
...this is my last attempt at getting the information I need to fix this monitor ...as the schematic for the fpf double sided print surface mount component version doesn't seem to exist..
I have a theory on this..
Since the later boards went double sided print ..and high density surface mount components ..I'm assuming the chinese manufacturer ..considers the whole board now a single component ..and thus not serviceable..
Absolute crap of course ..
They just dont_want_ it fixed ..
I'm uploading 3 successively closer pictures of the mostly repaired board ..the power fet ..switch mode chip ..opto and various other bits have already been replaced by me ..
BUT ..I cannot decipher the values written on the 2 resistors ringed in yellow
They are both o/c with burnt tracks lengthways across the letters and numbers ..
Particularly R861 wich I think starts 47 but the last number I cannot make out ..
Also R856 which might possibly be 15R0 ..but not sure ..
So ..I'm hoping some kind soul out there has the same monitor ..and would be kind enough to open it and read these resistor values for me ..
No need to meter them ..just tell me exactly whats written on them..?

Please...help me ..and stop the Chinese junk peddlers win yet another round.
rgds
VS

 

[Analoguesat]

If you can post a crop of a high res pic (cropped to just around the affected components) I'll have a go at reading the values by tinkering with the image properties

 

[Vipersan]

If you can post a crop of a high res pic (cropped to just around the affected components) I'll have a go at reading the values by tinkering with the image properties

Thanks AS ..but I suspect it wont make any difference ...I've had a high res camera on the 2 resistors in question ...the burn or track mark runs lengthways through the printed values ..and has vapourised the centre area of the resistors ..
effectively nothing there to read ..
for example a burn through an 8 ..makes it look like a zero as the centre is missing ..but it could just as well be a 2 or a 5 with just the top and bottom bars remaining so to speak ..
but thanks anyway..
VS

 

[Vipersan]

This is as close as I can get with my camera ..
The Hi def one was borrowed and went back a few days ago ..
cheers anyway ..
VS

 

[Analoguesat]

Overdriving the contrast and brightness the one nearest R861 looks like its got "28" on it to me. Would that make any sense?

 

[Vipersan]

Hi AS I'm 90% sure the first 2 numbers are 4 & 7 seen through a jewellers eyeglass ..
The combination of human eye and grey matter makes better sense of what _might_ be expected ..
The last number could be 0 or 2 or 3 or 5 or 6 0r even 8 ...1 4 7 9 are not possible..
Sorry to say the last image I sent is upside down ..so needs rotating through 180 deg..
applogies m8
and thanks for trying.
rgds
VS

 

[Channel Hopper]

I'm using an E173 in the office. If you can confirm it's the same I'll pull the back off tomorrow.

 

[Vipersan]

Hi CH ...
Sadly I can't confirm it is the same ..
There is a small chance its similar and might provide the info I need if close enough ...
BUT ...its the FPf thats important ..as this is the version or revision type ..
If for example it was an E173 PFc or PFb etc ..then it wouldn't even be close ...
If its an E173 FPf ....then theres a chance ...and I might be able to work it out from a good photo ..with as much detail as the ones I uploaded.
My best guess ..the 15 or 17 refers to screen site ...the 'E' to the design type ...and the FPf to the revision ...or board type fitted.
Please don't go taking the back off ..if its not at least an FPf....theres just no point.
Thanks buddy
VS

 

[Channel Hopper]

Ah, the receipt shows 'fPc on the end of it.

(phew!)

 

[Vipersan]

No probs CH ..
Thanks for even considering it..
rgds
VA

 

[Vipersan]

Just as a footnote ..please don't attempt this unless you are somewhat Tech Savvy...
To expose the pcb and get those values ..does require removing the case ...removing the screening and pcb en block ..and then removing the pcb temporarily ..
Tricky if you don't know how to do it ..
But requires a flat knife like a butter knife ...a philips head screwdriver ...and possibly a nut spinner or small pliers
rgds
VS

 

[Llew]

VS, have you tried tracing the resistors' path to any IC's that they may be hanging off of? I see there's an IC adjacent to the resistors.

It's the way I found duff resistors on one or two power supplies in the past. If you're lucky, the IC schematic (if you can find one) often gives possible resistor values, if only in the test circuits usually accompanying the IC info.

 

[Vipersan]

VS, have you tried tracing the resistors' path to any IC's that they may be hanging off of? I see there's an IC adjacent to the resistors.

It's the way I found duff resistors on one or two power supplies in the past. If you're lucky, the IC schematic (if you can find one) often gives possible resistor values, if only in the test circuits usually accompanying the IC info.

A very valid method Llew ...and one I've already persued ..
Sad to say ..the example cct gived in the ic pdf shows no resistors in these two locations ..
They show as wired directy from the IC pins to the power FET ..
The circuit has obviously been adapted to suit the FET thats actually used ..so these resister particularly the feedback one ..that I cannot read is critical ..for reliability
The resistors in question
One of them is connected from the IC to the gate of the Power fet ..pin 8 of the chip to FET gate ..
The other is in the feedback loop and is more critical ...connected between FET drain ..and a .39 ohm /1 Watt resistor to ground .....and pin 6 of the chip.
Neither is used in the example that comes in the chip pdf.
rgds
VS

 

[Llew]

Just out of interest VS, what's the type numbers of the chopper IC and FET? I'm always up for a bit of research when it comes to SMPS's

 

[Channel Hopper]

Just out of interest VS, what's the type numbers of the chopper IC and FET? I'm always up for a bit of research when it comes to SMPS's

If it's a 7552 IC then this may help

 

[Vipersan]

Just out of interest VS, what's the type numbers of the chopper IC and FET? I'm always up for a bit of research when it comes to SMPS's

Hi m8s ..
The FET is an A27611
and the 8 pin switch mode chip is an SG6841S

Had to source them in China to get replacements ...
might be available in the UK but I couldn't find 'em here ..and you can moltiply the cost by a factor or 6 > 10 usually..
rgds
VS

 

[Channel Hopper]

and the 8 pin switch mode chip is an SG6841S

Bing !

_http://translate.google.co.uk/translate?hl=en&sl=pt&u=http://www.forumnow.com.br/vip/mensagens.asp%3Fforum%3D32226%26topico%3D3009886&ei=b13yTqrtMcad8gOdmJiwAQ&sa=X&oi=translate&ct=result&resnum=8&ved=0CIMBEO4BMAc&prev=/search%3Fq%3DSG6841S%2Bequivalent%2B7552%26hl%3Den%26safe%3Doff%26prmd%3Dimvns

 

[Channel Hopper]

The FET is an A27611

Can't see that in any catalogue/search here. Could it be the A2761L ?

 

[Vipersan]

Can't see that in any catalogue/search here. Could it be the A2761L ?

The Very same CH ...
indeed its listed as both ...
Probably as the printed ident is so unclear ..

fleabay item 280779082214
rgds
VS

 

[Vipersan]

Thanks also for the link CH ..sadly it still doesn't identify the 2 resistors ..though explains the functionality of chip (at least the DIL through hole version)..
The resistors are very much dependent on the current requirements ..and the type of MOSFET used..
..and these need to be correct ..in order that the repair is reliable.

A service manual ..would probably have the current data required ..but like the schematic ..the manual isn't available.
rgds
VS