Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

[Dannyx]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

I think we're done here: tried to apply 3.3v to pin 8 of the 24C512 IC to see if anything might cause the 3.3v regulator to shut down and the smaller die of the CPU began to heat up. I'm not sure this is normal because it doesn't have a heatsink on, but I doubt it'd get that hot...

[Dannyx]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Oops.....Ok, big fail on my side I was still fixated on the idea that I should try replacing the original 25Q40 SPI chip with something else for testing, like I tried with the Q64, so when I saw C512 on there, it didn't occur to me to read more carefully, so I thought I should now seek out a Q512 IC to try in place of the 25Q40, which is a stupid thing to try because this is the EEPROM we're talking about, which is not only a different physical form factor but also has a different prefix - 24, instead of 25....so here I was, trying to fit this thing on the pads of the SPI IC, only to figure out it's too small and would NEVER be compatible anyway.

Good thing I stopped in time and read again more carefully, putting 2 and 2 together. I assume we're talking about this guy in the picture then Pulled it off and saved the contents, just in case it's of any use. Tried out what lotas provided but it still doesn't work. I don't know for sure, but it appears to have changed the blink pattern (or not, can't remember for sure): LED comes on and stays solid for a few seconds, then blinks twice rapidly, pauses for another second then repeats 4 more times (so 5 sets of 2 flashes before becoming solid again and repeating).

There's another thing I noticed: this EEPROM IC is not getting consistent power. I measured pin 8 and briefly got 3.3v at startup, which then went away and didn't return. Even stranger, NOW the blink pattern also changed: it no longer did the consistent pattern above, but seemed to be off most of the time. I thought it had something to do with my soldering, seeing how touching my meter probe to the pin caused a change in behavior, but that's not it. The resistance to GND of that pin reads 1kOhm. Touching the meter's probe to that pin causes this, as it keeps going otherwise...

[lotas]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

I noticed the first part is blank in this one.

That's how it should be.

[Dannyx]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Will do as soon as I have one. I noticed the first part is blank in this one.

[lotas]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

25Q40 - supports Quad, 24L40 - no, try rewriting eeprom 24C512.

[Dannyx]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

I tried it again today with a different chip but same story, even worse actually. I tried a 25L40 (as opposed to Q40) and apparently it doesn't have the 3 registers (only 1 column shows up in NeoProgrammer, so I can't set 42, only 88). I tried it out anyway just to see what happens and this time I didn't even get the standby LED to come on, so that clearly didn't work. It also tells me there is some communication present, even in this half-dead state, which enables the stand-by state, otherwise the different chip wouldn't make a difference, but it does, so most likely the problem is the flash.

I then tried a 25Q64 chip, since it has the two registers I can set and the LED comes on, but we're back to the original state (blinking twice), so the problem's not here sadly...

Another thing I tried, going back to my very first days of learning to fix TVs, I shorted the MISO and MOSI lines together as I plug in the power. The LED comes on solid then goes off after a few seconds and doesn't blink anymore after that until I release the pins, at which point it just goes back to blinking....thought I'd just give it a shot to see what happens, since the board's dead anyway...

[Diah]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Don't think I've done that and they all (seemed to have) survived so far

lucky you... seem yours PC old one with low currents 5V or non USB3

[Dannyx]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

ch341 will read and write all spi if the PIN 28 disconnect from circuit and go direct to 3.3V
otherwise will kill the chips

Don't think I've done that and they all (seemed to have) survived so far

[Diah]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

ch341 will read and write all spi if the PIN 28 disconnect from circuit and go direct to 3.3V
otherwise will kill the chips

[nomoresonys]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Good to know they still work, I must have gotten stuck with a bad one.

[Dannyx]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Wonder if you have a bad ch341, the one I recently had to return must have been bad, it read 2 chips, but could not read another after that, not even the first 2 that it read, all readings came back all ff.

The CH341 works just fine - as you can see, I am able to read/write chips, so it's the last thing on my list right now

[nomoresonys]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Wonder if you have a bad ch341, the one I recently had to return must have been bad, it read 2 chips, but could not read another after that, not even the first 2 that it read, all readings came back all ff.

[lotas]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

I haven’t tried this one, I don’t know.

[Dannyx]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Wonder if I could use a larger one, say a 64 IC, since I don't have a 40 one right now...

[lotas]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Try it, but it seems to me that this is not the case.

[Dannyx]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Status register in SR 3 should be 00, that is, all checkboxes are unchecked. Should be 88.42.00.
Also remove the checkboxes for "Locked" on SR2, SR3.

I think I did that the second time around. The order looks like this: put chip into programmer>detect it (I choose the closest one)>unlock>erase>blank check>open bin file>write bin file>open "edit SREG" >check the 4 checkboxes, uncheck the last one>hit write. Should I bother to try with a new 25Q40 ?

[lotas]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Status register in SR 3 should be 00, that is, all checkboxes are unchecked. Should be 88.42.00.
Also remove the checkboxes for "Locked" on SR2, SR3.

[Dannyx]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

Ok, I tried it several more times but no success.

I had some issues with ASProgrammer which wouldn't let me tick the QE box for some reason (first screenshot). I then tried NeoProgrammer which did - think there's some issue with the CH341...anyway. I'm sure I did everything right this time: removed chip, unprotected it, erased it, opened dump file, program, checked the 4 checkboxes you indicated and uncheck the one on the far right and hit "write", so I think the CPU's dead or no longer soldered properly. The jumper wire between the TRDY pads is still in place BTW, just to rule out the possibility of a bad panel.

There's another thing I noticed which makes me think the SPI chip is failing to communicate with whatever it's supposed to talk to (most likely the CPU): while I was trying out AsProgrammer, since it wouldn't let me tick the QE box, I just ignored that step entirely and installed the chip without setting any of the 4 options, just to see what happens - of course I got the same 2 flashes and nothing else, but from what I read in other posts where others tried it without setting 88 and 42, the TV just dumped FFs on top of the header there at startup, essentially corrupting the dump again. Mine doesn't do this - the header stays intact when I read it again. What's more, I noticed the 4 options ticked themselves when I pulled the chip off the board and read it a second time (second screenshot). I didn't touch anything, except hit "read". The TV DID something to it though, because I used HxD to compare the BIN on my PC with what the SPI chip had on it after powering on the TV and there are some changes deep down in the file - some FFs in the original now had other random values. Attached the BIN that resulted after trying the dump from post #20, should it be of any use...

[lotas]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

If there were only FF in the dump header, then the TV would not even have a standby mode and the red LED would not light up either.

[lotas]

Re: Samsung ue55mu6202k bn94-12778s Not turning on (dump help ?)

First write down your native one, then my pure one, but only with stasuses...
First, remove the protection, uncheck all the boxes, then erase the chip completely, write dump, set the register statuses and register them.