I have a Vizio P50HDM. The old "pop of death" occurred again which is the second time in less than two years. The repair shop replaced the y-sus board the first time but I am being led to...
Hi, i just got thesame problem as you do! The zsus board situated at the left corner when behind the tv is usually the cause. Apparantly the Hybrid IC yppd-j015b could be damaged since it is the recipient of the approx. 192v DC. There is a fuse which protects it, but at times goes off with it. It is usually caused by overheating and in my case, i took a closer look underneath the Hybrid IC and found tinny 'tainted sparkles' on the heat sink which was caused by one SMD (surface mounted device)capacitor. This caused a spark, or what many call ''POP OF DEATH'' ,- a short circuit , 192V TO GROUND, the heatsink!
Infact, when the person who owned the tv complaint of hearing a pop sound, when i opened the tv myself and switched it, i could see that it came on, there was sound, faint picture exactly as you described but as i was gazing, i SAW the spark, again but this time even the faint picture disappeared.
It was a good thing that i saw the spark! Now what had happened was that the first pop did blow up low value smd resistors and MOSFET smd in the Hybrid IC yppd-j015b but kept the tv on with no picture so the second time i saw the spark made matters worse, the fuse went off and other MOSFET sms (s).
Now in all of this, you have to have more than basic knowledge of electronic repairs to even start opening the tv because of many reasons:.Anti static components, MOSFETs,etc just to remove the yppd-j015b hybrid ic without the proffessional desoldering equipment, feels like battling with a puckupine! Because of lack of proper desoldering equipment, most technicians advice people who dare try to REPLACE the Z SUS and Y SUS boards.
If you can, just make sure you replace the bad parts yppd-.... included and place anti heat isolation underneath the ic or add two more super quiet fans to cool off.
Before replacing parts, take very close looks at the surrounding parts for physical damages and test if not all resistor and diodes arround for shorts.