Hi There!
I just wanted to share experiences trying to fix for the first time a CFL backlight Tv. It is samsung LE32A336J1N
The issue it was showing was: As soon as I turned it on, the BL would turn on/off for 2-4 times and them off definitely
I suspected the BL voltage generator or the LED strips, at least until I opened it up, cause I had never seen these TV's
When I opened it I found a very robust TV with a complex chassis formed by mutiple arms tied together with screws. There was a large PS board with several transformers for backlight, a Main board, an a T-con boards. There was also a board-edge connection between all the right side of the PS board and a plastic block with 12 press-on contacts
I first tested components in the PS. Desoldered all caps to check them with a ESR meter and they were all good. Checked for shorts in diodes and Q and all well. Did some resistance comparison at all HV outputs and they all measured the same values.
So I went ahead to disassemble the plastic block containing what I had already realized was going to see a set of thin CFL tubes. Took a while to remove it all and I finally got to the tubes. I was expecting to see one of them really dark but no, they were all looking the same, just some dark tint at both ends
I turned on the TV with the BL exposed and realized that tube #5 was off towards one end. I swapped this tube into position #6 and the same tube failed. Butthen I moved this tube to position #12 and the backlight kept ON all the time. For some reason the current detection on this circuit seems to be more tolerant. The tube was still off at one half but in this position it didn't make the inverter to stop
So I put all the parts back together ( I wasn't expecting to be able to be able...) and the TV is working fine for $0. Not too worth as this is an old TV that dones't tune HD DTV channels but here we have the NON-HD alternative channels available for all station.
Just wanted to share!!
I just wanted to share experiences trying to fix for the first time a CFL backlight Tv. It is samsung LE32A336J1N
The issue it was showing was: As soon as I turned it on, the BL would turn on/off for 2-4 times and them off definitely
I suspected the BL voltage generator or the LED strips, at least until I opened it up, cause I had never seen these TV's
When I opened it I found a very robust TV with a complex chassis formed by mutiple arms tied together with screws. There was a large PS board with several transformers for backlight, a Main board, an a T-con boards. There was also a board-edge connection between all the right side of the PS board and a plastic block with 12 press-on contacts
I first tested components in the PS. Desoldered all caps to check them with a ESR meter and they were all good. Checked for shorts in diodes and Q and all well. Did some resistance comparison at all HV outputs and they all measured the same values.
So I went ahead to disassemble the plastic block containing what I had already realized was going to see a set of thin CFL tubes. Took a while to remove it all and I finally got to the tubes. I was expecting to see one of them really dark but no, they were all looking the same, just some dark tint at both ends
I turned on the TV with the BL exposed and realized that tube #5 was off towards one end. I swapped this tube into position #6 and the same tube failed. Butthen I moved this tube to position #12 and the backlight kept ON all the time. For some reason the current detection on this circuit seems to be more tolerant. The tube was still off at one half but in this position it didn't make the inverter to stop
So I put all the parts back together ( I wasn't expecting to be able to be able...) and the TV is working fine for $0. Not too worth as this is an old TV that dones't tune HD DTV channels but here we have the NON-HD alternative channels available for all station.
Just wanted to share!!
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