Re: Samsung LN40D630M3FXZA Has Backlight and Sound, No Picture

Hmm..., noone has seen an LCD displaying a pattern like this before? I would really like to know whether it's worth replacing the T-Con board to see if that fixes it or whether these are the symptoms of a failed panel and I should just toss it to make more room on my workbench.

I have a digital scope btw if there's anything else I could test for...

Re: Samsung LN40D630M3FXZA Has Backlight and Sound, No Picture

Hi, I am trying to repair a Hisense HL46T39PZLN3D LED-backlit display with a similar problem.

Transistor QD1 on T-con board SD120PBMB4C6LV0.0 is not turning on (12V on gate), it's gate capacitor is not shorted, and transistor QD2 is not shorted/burned. I could not figure out where the gate-signal for QD1 goes to as the trace disappears into the middle layers of the board and couldn't find a connection.

I attached a wire to temporarily bypass QD1 just to see if the panel is damaged before ordering...

Hi, I'm trying to repair a 1080p Samsung plasma display, PS-50P91FD.

It turns on and makes the startup sound, then primes the display with a flicker and continues glowing faintly. Sound input works. Makes 5 flashes of the red LED then stops flashing (off).

Vs, Va and Vg are correct. Didn't test Vsc. All fuses I could find (glass and poly) were fine. No obvious damage.

I shorted pins 3 and 4 on the four-pin square vertical header on the control board, and removed the LVDS cable from the control board. There was no test patterns, just the same glow as...

Re: Philips 42PFL9632D/79 2-secs-to-black

In the last post I meant SoftStart was pin 23 instead of pin 26. I must have miscounted them.

Anyway I think I've found the problem.

The BD9897FS controller IC on the slave was getting very hot (whereas the master one was cool). Between Vcc (26) and SW1 there was 10 ohms, whereas on the master the two pins had no connection between. (I desoldered the IC and there was still 10 ohms between them). SW1 is the "lower rail voltage for HN1 output". As far as I can tell it is a reference input for the high-side...

Re: Philips 42PFL9632D/79 2-secs-to-black

Hi
I am having a simmilar problem with a LC420WU5 inverter board as the OP. I don't have the back cover of the TV with me at the moment so can't give the exact model number, but I believe it's the same / simmilar to the one in the thread title.

When the TV is turned on, the blue LED turns on on the inverter board which then emits a buzzing sound from the transformers. About two seconds later the LED fades off and the backlight cuts out. Then the backlight starts turning on and off about once every second, with the transformers...

Re: New Members - please post your introductions here

G'day

Really just joining for all the smps stuff. I've done heaps of electronics-related stuff. I've replaced my fair share of dead capacitors in discarded monitors and TVs, and modded heaps of atx powersupplys (at least tried to), but I wanted to take it further so I thought I might as well join this forum.

Location: Western Australia
Interests: Electrics/electronics and computers, and verge collecting of course

~Josh