Mulja tv repair portal
Equipment Repairs => LCD TV forum => Topic started by: E Parton on November 25, 2011,14:34:36
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Hi friends ....
I thought this one was going to be straightforward ...but its turning into a nightmare.
My customer complained he had no freeview channels ...which was true ...but not just missing channels ...missing menus ...so couldn't perform a re-scan
When the dvbt button is pressed ..I just get a blank screen ..
Analogue is fine as is an external source on EXT1 or EXT2
So ..back removed and psu board examined ..
2 x leaky electrolytic caps ...
These were both replaced ...as was the 24C32 eprom ...
New blank 24C64...
The set bas powered up ..and the new eprom written ...but still no dvbt/freeview..
I borrowed a pretuned (channel map already stored) dvb board from a 42 inch Samsung ..
Popped this on the main board edge connector ...and was rewarded with a picture ....well several ..as the channels were already stored ..
Back came the dvb menus ...but a poor picture ...so ..I did what you'd expect ..and went into the service menu ...and performed a reset ..
This had the effect of disabling the dvb menus and wiping the channel map ...so now I have 2 non performing dvb pcbs
Im convinced this is an options problem and that the tuner which is on the main board ..not the dvb board ..is not identified correctly ..but cannot find an option to switch it on ..
has anyone encountered this issue before ..
Possibly corruption of the stored option bytes by ota upgrade ..or faulty psu ..
And has anyone got a service manual for this model ..or similar that I can use to research the options.
Failing that ..has anyone got access to one of these specific sets ..and can access the service menu ...and make a list of the correct option settings that relate to the tuner type
Any help would be appreciated ..
I cant even find a reclaimed main board on ebay ..
at least not one at a price that would make the repair economic
rgds
E Parton
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elektrotanya to the rescue..
http://elektrotanya.com/samsung_ged32se_ged40se_gnd40se_gnd46se_chassis_le32m73bd_le32n73bd_le40m73bd_le40n73bd_le46n73bd_sm.pdf/download.html (http://elektrotanya.com/samsung_ged32se_ged40se_gnd40se_gnd46se_chassis_le32m73bd_le32n73bd_le40m73bd_le40n73bd_le46n73bd_sm.pdf/download.html)
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let me know the dvb tuner card number if its the older two piece type I may well have an old one you can have with my blessing.
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@ Bambooz ...
Do I need to be a member to download from electrotanya ?
Can't see an active link to click on the page ?
@Jim ...Thanks for your kind offer ..
I don't think the fault is actually on the dvb sub board ...as I've tried a replacement ..
Still not seen by the set ..
..and I know its a good one from a 40 inch version of the same tv ..
I suspect the fault lurks on the main board ..
.and that I dont have ..as a 40 inch board wont fit ...wrong connectors..
rgds
Cheers guys ..your help _is_ much appreciated
Evan
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you dont need to be a member sometimes you gotta refresh the page for the link to appear the server can be a wee bit slow give me the main pcb no may have one o' em too used to scavage lots of smashed screens for bits !
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Many thanks Jim ..
Better still I'll take a good photo of the main board ..and send it to you ..if thats ok ..?
will do it tonight ..
rgds
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Ok Jim ..
Photos sent ..
I hope they are clear enough ..
..and thanks again ...I appreciate your help.
rgds
Evan
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@ Bambooz ...
Do I need to be a member to download from electrotanya ?
Can't see an active link to click on the page ?
2 downloads per day for non-registered members.
open the page in firefox (if possible) and wait a couple seconds.
the text "This file is downloadable free of charge from the site... processing" should change to "Get manual" after a bit. Doesn't really work in all browsers though.
anyways.. i've reuploaded it here:
http://www.4shared.com/document/zEU8eGQY/samsung_ged32se_ged40se_gnd40s.html
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Many thanks Bambooz..
I now have the manual ...from 4Shared ;)
appreciated m8
Evan
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Hmmmm ...not looking good
I've checked the options table gainst those refered to in the service manual ...
They look pretty much the same ...so chances are this set has now a corrupt flash on the main board ...or possibly a physical hardware fault ...and is not 'talking' to the dvbt sub board during reset.
According to the manual it is possible to re- flash the firmware with a serial flash jig ..
Which comprises nothing more than an adapted serial lead connecting a pc/laptop from rs232 to the service jack socket ..
A special flash loader program ....and Hyper Terminal ..
Nothing that isn't practical or possible ..
Except ...no actual instructions on where to obtain this elusive loader program ....the adapted serial lead ..and most important ...a copy of the actual firmware.
Typical ...
I suspect that process is Samsung 'in-house' only...and Non specific Tv Engineers are excluded.
If this _is_ the case ..my only option would be to try and obtain and fit a replacement main board..
Well done Samsung ...looks like you've managed to make a repair at this level ...elitist..
rgds
to all
Evan
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the cable shouldn't be a problem. If the TV has a 3.5mm headphone service jack, the cable is called ExLink
http://wiki.samygo.tv/index.php5/Enable_Serial_Console_on_non_CI%2B_Devices
if it doesn't, it get's a bit hacky..
http://wiki.samygo.tv/index.php5/Ex-Link_Cable_for_C/D_Series
the main problem is getting the firmware tool and the firmware itself.
Haven't found anything in an hour worth of searching. Well actually i found the tool, but the download was taken down by Samsung (DCMA request) :(
Even if you found the tool somehow, you still don't have the firmware to flash it.. so it's kinda pointless.
Are all the LDO's working? I've had a Samsung LCD monitor once which went berserk because a 2.5V LDO was going down to less than 2V under load.
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Hi
Try putting the set into analogue and then carry out a plug and play
Brian
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Hi
Try putting the set into analogue and then carry out a plug and play
Brian
Already done Brian ...During Plug n Play setup ...the DVBt section of the tV isn't accessed ...
Its simply not recognised ..as though it doesn't exist ..
And yet a preprogrammed DVBt sub board borrowed from a 40 inch TV will bring up the missing menus ..and produce picture ..
Sadly that TV and its board has since been returned to the customer ..but it does prove the sets tuner (on the mainbaord) is ok ...and that the set _should_ be working in DVB mode ...but alas it looks like the option to activate it from plug and play is missing from the firmware ..
Round and round we go ...and I'm still convinced this is a corrupted firmware /flash (not eprom) issue ..
rgds
Evan
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the cable shouldn't be a problem. If the TV has a 3.5mm headphone service jack, the cable is called ExLink
http://wiki.samygo.tv/index.php5/Enable_Serial_Console_on_non_CI%2B_Devices
if it doesn't, it get's a bit hacky..
http://wiki.samygo.tv/index.php5/Ex-Link_Cable_for_C/D_Series
the main problem is getting the firmware tool and the firmware itself.
Haven't found anything in an hour worth of searching. Well actually i found the tool, but the download was taken down by Samsung (DCMA request) :(
Even if you found the tool somehow, you still don't have the firmware to flash it.. so it's kinda pointless.
Are all the LDO's working? I've had a Samsung LCD monitor once which went berserk because a 2.5V LDO was going down to less than 2V under load.
Thanks for all your searching m8 ..
Sounds like you arrived at the same conclusion I did ..
Samsung don't want this in the public domain ..
Either Flash tool ..or Firmware ..
Also ..fairly sure there are no faulty LDOs ...as I have had the dvb section working with a borrowed sub board ..
But can't activate dvb with its own board ..which is ok ...of that I'm sure too..
rgds
Evan
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Just in case anyone is curious ..
I've spent hours searching ebay for a working board ...
Nothing at all
BN94-01077B
Not surprising as there must be hundreds of variations to this board ..
Some very similar ..but maybe 2 sets of phonos instead of 2 scarts etc etc ...
Anyway ..there is a picture ...but sadly not a board listed at Sendz..
Here is a link in case anyone wants to see the culprit ..
rgds
Evan
_http://www.sendz.co.uk/index.asp?function=PRODUCTIMAGEWINDOW&closedelay=20000&SRC=http://www.sendz.co.uk/ekmps/shops/mickclark/images/samsung-le40n73bdx-xeu-bn94-01077b-main-av-147-p[ekm]326x300[ekm].jpg
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..Hi friends ..
Spent most of my morning searching once again for a replacement main board ..
..and maybe I found one that will do the job ..
BN94-01077E
Whereas mine is a BN94-01077B
It certainly looks the same ...i/o connections etc ..
but the number is slightly different ..
Anyone know if there is enough difference to be an issue ?
Its a bit pricey ...so don't want to make a mistake if I do decide to buy it ..
Unless one of you guys has an exact match ...I might well have to take the risk..
The company selling it is SJS ....
Anyone had dealings with them before ? ..and if so ..are they reliable ?
rgds
Evan
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hi
yes good firm send him a email he might be able
to say if compatable
dave
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Thanks Dave ..
Surprised when Stewart from SJS rang me an hour or so ago ..
I had emailed them with my address and details ..but without a phone number ...so was quite surprised when he rang me ...having obviously gone to the trouble of finding the phone number himself.
We discussed possibilities ..and there is good chance the 'E' board can replace the B board ..after various links have been moved which relate to the type of lcd panel fitted ..
We've agreed that I should keep searching for an exact match over the weekend ..but should I come up empty handed by monday ..I'll order one from him ..and attempt to modify and fit it.
..and there is a discount available to Trade registered customers ..
rgds
Evan
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Cure or pure fluke ??
I took the plunge and ordered a BN94-01077E board ..
Mine was BN94-01077B and couldn't source one anywhere ..
The board arrived this morning ...and although plugs and connections are the same ...its designed to drive a completely different LCD panel thus ...it can't be fitted without major board surgery ..
So I fitted it anyway ..but didn't plug in the lcd panel ...
Connected the dvbt boards to the top edge connectors and powered up..
It went through the initialise process ...but obviously there was bo picture ..
I then removed the main E type board and refitted the B type ..and the previously connected dvbt board ..
My intention was to give up and tell the customer ..he'd have to use a freeview box with it ..but to my amazement ...the dvb menus were back ??
Fluke ...coincidence ..or cure ?
Still not sure ..
It _may_ be that the E board wrote something to dvbt board during its brief lcd panel-less boot up ...making it initialise ...
I'll probably never know ..but a result is a result ...
And the set now functions correctly..
rgds
Evan
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...Hmm
..although I now have this set essentially _working_ ..
I still have an issue insofaras
The backlight shuts down ..ie no brightness/picture ...but ONLY occasionally and for short periods ..when the set is displaying a Dull low brighness Low contrast image ..
Once the broadcast changes to a brighter image ..say a studio picture ..the backlight comes back on ..and a picture is displayed.
In other words ..the backlight is either on or off depending on picture content.
Does anyone know if this is fixable ? ..perhaps by tweaking a setting in the service menu ?
rgds
Evan
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...Hmm
..although I now have this set essentially _working_ ..
I still have an issue insofaras
The backlight shuts down ..ie no brightness/picture ...but ONLY occasionally and for short periods ..when the set is displaying a Dull low brighness Low contrast image ..
Once the broadcast changes to a brighter image ..say a studio picture ..the backlight comes back on ..and a picture is displayed.
In other words ..the backlight is either on or off depending on picture content.
Does anyone know if this is fixable ? ..perhaps by tweaking a setting in the service menu ?
rgds
Evan
...Just a gut feeling ...
But ..I think this might be related to the Dynamic Dimming function in the TV .
Checking the service menu ..I can see this function set to'on' but is greyed out so can't switch it off to test my theory ..
Anyone know how to do this ?
rgds
Evan
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After some more digging on the net ..I discovered that disabling Dynanic dimming isn't an option on this model..and that it _can_be troublesome on certain sets..
I'm guessing that the combination of this feature being active ..and an lcd panel thats 5 years old is responsible ..
I did find however that ..selecting movie mode allows or automatically disbles the DD feature ..
I selected this mode and set up the TV for the best picture I could get..
Result is...the problem seems to have dissappeared ..
So far ..so good ..
But it would have been better to totally disable DD ..but can't.
Nice one Samsung ..more stupid tactics..
rgds all
Evan
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Could it be a fault with the inverter?
Maybe it's trying to just dim the backlights, but for some reason they go out completely.
i.e the inverter is working only on full brightness and for some reason is incapable of running at less than full brightness.
Is there a user option to dim the backlights, if so does that work, or do they go off as soon as you select anything other than full?
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Hi Dave ...
Not impossible that the invertor could have a threshold issue ...
But I'd be more suspicious about ageing ccfls.
However ..the set ran all day in film mode ...and in this mode its possible to set the brightness level so am guessing ..since it didn't cut out once on low level picture content ...it is more likely the dynamic dimming is the issue ..
Many users of these sets have reported flickering issues on certain picture content ...and have been forced to use the method I outlined to effectively ..disable DD ...though on some versiond the R and S models (mine is N) this can be switched off in the service menu ..
Many have done just this ...to combat the known flicker issue ..
I suspect my backlight cutout problem is just an extension of this problem emphasised by ccfl ageing.
There might have been a firmware fix for this broadcast for this model ..but If the set 'missed' the upgrade ..it won't have it.
Just a theory...but I've spent enough time and money fixing this TV ..so the customer will just have to take it back and run it in film mode ...with an explanation of course.
;)
cheers
Evan