Yesterday, I picked up a Panasonic color TV model TC-2588 from a collection of around 50 units. The casing looks clean and well-preserved. After coming back from work, I opened the unit and tested the three main boards—everything seems to be in good condition. The power supply uses a STR-S6307, and the fuse is intact. I checked the voltage at Q804, Q826, and Q827, but the base voltages of the protection transistors are fluctuating between 0.5V and 0.9V (which should normally be 0V). When I connected a 100W incandescent bulb as a load, it didn’t light up, which means the power supply is still faulty. I decided to check the protection circuit more carefully. The most suspicious component was the optocoupler D836 (TLP621). I removed it and tested the resistance between pins 3 and 4—only about 350 ohms, which is way below the normal value of around 10k ohms. The power supply itself seems fine, so I moved on to check the downstream components. There’s no obvious short circuit, and when I connected the load, the screen showed a red raster with snow noise. Could this be due to an aging CRT? The voltage for the red gun is only around 60V, and the red picture tube appears darker than the other two. Also, it gets quite hot. When I turned the TV on, the black-and-white image looked normal, and the AV input showed bright colors with good brightness and contrast. I’m wondering if the issue is just due to age or if there's something else wrong. I thought this TV might be worth around $50, but I'm not sure if it's worth fixing or not. Maybe I’ll try replacing the optocoupler first and see if that helps. If not, maybe it's time to move on. Rack Mount Battery,Home Energy Storage Battery,Residential Energy Storage Systems,Home Energy Storage Systems JIANGMEN RONDA LITHIUM BATTERY CO., LTD. , https://www.ronda-battery.com