Samsung LE40R81b not turning on (relay clicking on and off)

[attainteddragon]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

thanks guys. i am getting more and more of a stockpile of what seems to be eeprom issue tv's. i have not found a great deal of info on youtube and some of these models seem to have driver issues. the more info we can get, the better.

[dskall]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

Does anyone know why you cannot read the data while on the board. I bought a programmer thinking I would just clip on to it and read eeproms from tv repairs. I don't really want to desolder each time and take a chance of damage. Also are you freezing chip before you try to read from corrupt eeprom?

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

Does anyone know why you cannot read the data while on the board. I bought a programmer thinking I would just clip on to it and read eeproms from tv repairs. I don't really want to desolder each time and take a chance of damage. Also are you freezing chip before you try to read from corrupt eeprom?

No, I desolder the thing and try it out on the programmer. In this case, I saw some numbers showing up, but with no way of knowing what they should be, I just wiped the chip and put it back in place. Plugged the TV in, it power-cycled a few times before finally coming on....not for long though, as it shut down after around 20-30 seconds, so the searches are still on. Might still be a bad cap somewhere or the EEPROM chip is still bad.

[vinceroger69]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I freeze spray ics too firstly see if its the eeprom at fault if the set works i then remove the ic re freeze whilst on programmer then read it quick then re write to a new blank ic i have only done a few so far and gave sets to family etc and no ones brought any back so persume there ok .i do have the clip to read in circuit but im sure ive read it dosnt read the ic correctly? so never bothered trying.

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I freeze spray ics too firstly see if its the eeprom at fault if the set works i then remove the ic re freeze whilst on programmer then read it quick then re write to a new blank ic i have only done a few so far and gave sets to family etc and no ones brought any back so persume there ok .i do have the clip to read in circuit but im sure ive read it dosnt read the ic correctly? so never bothered trying.

Might actually try that: freeze the IC while still on the board, turn the TV on and quickly reset it so it writes whatever it needs to onto the chip and then swap it over...worth a shot.

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

UPDATE: I put in a new EEPROM but the problem persists. I even took off the metal shield and checked the caps with the method suggested by Dskall (putting my meter on VAC and probing across the cap), but most of them showed 0, while others, although showing like 5-6v, upon replacing them still returned that same value, so I don't know what the problem could be...the processor could be coming loose, though not wanting to kill the thing completely (since the client probably wouldn't like it), I didn't attempt to reflow it, as reflowing TV board never proved successful (for me at least). Still, I think it's a software issue, as the turn offs are too equally spaced to be a power supply issue, as those are mostly intermittent...

[Dannyx]

Samsung LE40R81b turning on and off every 20-30s is now FIXED

UPDATE OF THE UPDATE: in a fantastic turn of events which can only be described as one of those "what if we try this" moments, I think I managed to fix this TV. Get this: we've already established that swapping the EEPROM didn't help, so with the new EEPROM in place which allowed the TV to stay on for a brief period just like before, I accessed the service menu and instead of going straight for the reset option, I went to the first sub-menu, which I believe is OPTION or something like that and there I found an option "something READY" - YES/NO. This was set to NO. I can't remember what the exact option says (and I'm NOT going back in there to check, for fear it'd mess something up again ), but I thought "wait, why WOULDN'T this be "ready" ? Let's try changing it to YES to say it IS ready...what would happen ?" I did that, cycled the power to leave the service mode and the TV suddenly stays on. As I'm writing this, it's been on for about an hour and it seem to be running without a glitch. So the next time you're faced with this issue, swap or erase the EEPROM but also set the first option in the service menu to YES if it happens to be set to NO and the TV power cycles. Not to sound cocky or anything, but if this works till the end, it should be marked as sticky Must admit I haven't encountered this solution being suggested anywhere, not just here. Cheers guys

[dick_barton]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

Does anyone know why you cannot read the data while on the board. I bought a programmer thinking I would just clip on to it and read eeproms from tv repairs. I don't really want to desolder each time and take a chance of damage. Also are you freezing chip before you try to read from corrupt eeprom?

With the EEPROM still soldered in the set, the EEPROM supply line from the programmer (5V or 3.3V) would also attempt to power everything else attached to the onboard EEPROM supply line and may well not have sufficient current to deal with the current demanded by the mainboard.

[dskall]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

So maybe could just lift vcc or open trace to vcc

[dick_barton]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I suppose the simple answer would be yes, that may well do the trick but I don't find it difficult to quickly remove the EEPROM and then drop it back after reading.

[Dannyx]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

So maybe could just lift vcc or open trace to vcc

Not really possible, since there isn't a physical jumper between the IC and the rest of the board which can be removed, so you're MUCH better off removing the chip than trying to isolate it...takes less than a minute with a blast of hot air at 400 degrees C.

[dskall]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

Well I am getting better with hot air method. The last I removed with iron and took a couple of resistors with it. So am still hesitant about just removing parts off good board

[dick_barton]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

Practice on old boards.

[attainteddragon]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

just got to play with one of these.

had a failed secondary cap and someone else had already replaced 2 others.

13v on ps was reading closer to 14v

ps cycling on and off.

did the eeprom reset by shorting p5 and p6.

unit was now responsive to the remote, but no back lights.

checked the screen for a pic with a torch, but nothing visable.

found bl/on command missing, so disconnected cn1803 and jumped det_5v to inverter on/off.

backlights came on, so ps and inverter are good.

lift the screen up to find a nice crack across the panel that i couldn't see before.

oh well, learnt a couple of new things on this one.

[tiny68]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

DannyX - I have just gone on the same journey as you described with a LA32R81. It had a tcon board problem and I also had the constant re-booting. After fixing a tcon board, I found that it continued to re-boot. I replaced the EEPROM with a new IC and forced SDA to Vcc for 30secs on power up - clear/re-write the EEPROM settings, but the same behaviour - rebooting.
In desperation, tried the setting you mentioned in the Service menu (from "off" to "on", as you indicated) and on restart, it appeared to stay on ok. I went back into the Service menu to change the setting back, but it started doing the reboot cycle thing again.
I haven't had time to recheck the other setting in the Service menu, and at the moment I cannot find any digital channels, but at least the unit does appear to be stable now.

Many thanks for exposing this apparent fix to an annoying glitch with these TVs.

[jimbofz]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

just got to play with one of these.

had a failed secondary cap and someone else had already replaced 2 others.

13v on ps was reading closer to 14v

ps cycling on and off.

did the eeprom reset by shorting p5 and p6.

unit was now responsive to the remote, but no back lights.

checked the screen for a pic with a torch, but nothing visable.

found bl/on command missing, so disconnected cn1803 and jumped det_5v to inverter on/off.

backlights came on, so ps and inverter are good.

lift the screen up to find a nice crack across the panel that i couldn't see before.

oh well, learnt a couple of new things on this one.

ive read this post with great interest,

as i too have had similar problem with LE40 R87 DBX.
on mine theres not enough on/off volts to keep the relay from clicking out every few seconds ,so no sound and no backlights, its only 2,8v should be high for psu on low for off .

when i unplug small plug from psu to main board
cn1803 and link 5v to inverter on ,backlights come on .
.ive replaced the usual suspects all the caps on psu 1000uf
and removed screening plate to access the surface mount caps inside on main board
,most measured fine on my esr meter but replaced them anyway. mainly 100uf and 1000uf tried heating up the main board with hairdrier no change .so i need to enter service mode but cant until i can stop the relay cutting out every 10 seconds. so im in catch 22 cant enter s mode until i can keep psu running .


ive read that removing and replacing eeprom is the next step ,but before i do im trying to understand why the power on volts is low
and why i cant get any
display, screen remains dark .led responds ok blinks with remote commands
any ideas ?

[cheeky2]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I have repaired a few of these models, so I talk from experience.
First ensure your capacitors haven't failed in your psu.
If they have been replaced in the past (normally tell with someone using a different brand and from soldering underneath board), then the ripple from the psu would have likely failed caps on the main board underneath metal screen.
Also the atmel 24c256 ic can also get corrupted, this can be blanked out in situ with a clip on the device without removing the eeprom (cheapest option ch341A programmer with the appropriate clip on for the 8pin smd). The next time it boots it will take longer to boot as the software is loaded from the onboard memory on the main board.
These are the most common issues with these.

Goods luck

ive read this post with great interest,

as i too have had similar problem with LE40 R87 DBX.
on mine theres not enough on/off volts to keep the relay from clicking out every few seconds ,so no sound and no backlights, its only 2,8v should be high for psu on low for off .

when i unplug small plug from psu to main board
cn1803 and link 5v to inverter on ,backlights come on .
.ive replaced the usual suspects all the caps on psu 1000uf
and removed screening plate to access the surface mount caps inside on main board
,most measured fine on my esr meter but replaced them anyway. mainly 100uf and 1000uf tried heating up the main board with hairdrier no change .so i need to enter service mode but cant until i can stop the relay cutting out every 10 seconds. so im in catch 22 cant enter s mode until i can keep psu running .


ive read that removing and replacing eeprom is the next step ,but before i do im trying to understand why the power on volts is low
and why i cant get any
display, screen remains dark .led responds ok blinks with remote commands
any ideas ?

[jimbofz]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I have repaired a few of these models, so I talk from experience.
First ensure your capacitors haven't failed in your psu.
If they have been replaced in the past (normally tell with someone using a different brand and from soldering underneath board), then the ripple from the psu would have likely failed caps on the main board underneath metal screen.
Also the atmel 24c256 ic can also get corrupted, this can be blanked out in situ with a clip on the device without removing the eeprom (cheapest option ch341A programmer with the appropriate clip on for the 8pin smd). The next time it boots it will take longer to boot as the software is loaded from the onboard memory on the main board.
These are the most common issues with these.

Goods luck

thanks for your post
can you talk me through the process please,
does the clip just short out pin 5 and 6 sda and clock data?
ive looked at the ch341a and will buy no problem
so does the panel have to be removed
then the ch341a ,plugged into p/c usb skt ,and then the clip fitted across the eeprom to enable the chip to be erased then re written, so does the chip have a supply volts from the usb ,via the pc?

[cheeky2]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I suggest you read other posts about the ch341a.
No removal of the eeprom is required all you do is place the clip onto the ic ensuring you have pin 1 lined up correctly with pin 1 on the eeprom then use the ch341a software to erase the eeprom ensuring you select the correct eeprom from the menu. It is always best practice to read the contents first, then save it and finally erase the eeprom.
Asking about pin 5 and 6 only tells me you are unfamiliar with what the programmer does. It has the potential of reading , writing and erasing eeproms and spi flash ics
I suggest you download the programme first and read about the programmer, all the information is available from this site. Then purchase one once you understand what you are doing.
Use the search feature with google as I find the search on here unreliable to get the correct results!

[jimbofz]

Re: Samsung LE40R81b not turning on (relay clicking on and off)

I suggest you read other posts about the ch341a.
No removal of the eeprom is required all you do is place the clip onto the ic ensuring you have pin 1 lined up correctly with pin 1 on the eeprom then use the ch341a software to erase the eeprom ensuring you select the correct eeprom from the menu. It is always best practice to read the contents first, then save it and finally erase the eeprom.
Asking about pin 5 and 6 only tells me you are unfamiliar with what the programmer does. It has the potential of reading , writing and erasing eeproms and spi flash ics
I suggest you download the programme first and read about the programmer, all the information is available from this site. Then purchase one once you understand what you are doing.
Use the search feature with google as I find the search on here unreliable to get the correct results!

Thanks for taking the time to reply ,
i will order one today and as you said read up on usage ,good man thanks
just curious
i only mentioned pin 5 and 6 because i read on here on another post that someone had suggested this .
im a retired tv man with many years experience
and i know shorting out pins of an eeprom is not in my mind a good idea .
being able to erase and rewrite eeprom in situ is simpler than removing surface mount chip . what confused me was the missing inverter on voltage and low power on volts