Samsung HLS7178 – Weird Intermittent Startup Noise
Descrition of problem:
The noise from the video is consistent (in duration and sound), and it happens every 6 or 7 times the set is powered up. If it is one of those times it makes the noise at start-up, it also makes a quick “cough” at shut-down (one quick burst of the noise in the video).
Aside from this noise, the set works/functions perfectly as far as I can tell (even during the times it makes the noise on startup, everything seems fine once the noise stops). It appears to me that the brightness level/output may be lower when the noise happens, but I cannot be 100% sure of that. Best Buy had sent out a very poorly trained technician at one point who thought the noise may have been the color wheel, but he disconnected the color wheel and was still able to recreate the sound. The only way to reliably recreate the sound is to go into the Service Menu and adjust the DB Gain setting – if I do that and jog the value up/down, eventually I hear this same noise.
I think an important thing to note is that there’s no middle-ground on this noise; it either completely makes the exact same noise on start-up, or it starts up/shuts down whisper-quiet. There’s never just “a little bit” of the noise.
This behavior started after a tech had come to fix an “image flickering” issue in November 2007; at that time, she replaced the ballast and the Dynamic Black Assembly. The flickering went away, but this intermittent noise began. I contacted Best Buy and got a replacement lamp sent out to me to see if that was the issue, but the noise still happens with the new lamp.
My gut says this is an issue with the Dynamic Black assembly, but I want to be sure it’s that if I get someone to come out and replace it again (I really want to avoid a whole LE replacement, as the set is calibrated).