Full Service Recap PVM and Macs ACT

Sony KV-AR21M30 that suddenly stopped working. Complex diagnostics leading to full restoration. Of note was being able to source genuine Sony parts. Outline of Work Completed 12,14,16,19,22/12/2025
Failure analysis shows high voltage leak across switching regulator related to D623 shorting and PS603 going open circuit on another rail. Schematic studied in depth with testing of components including desoldering for out of circuit comparisons.

TV turned on first go after the following replacements were fitted:

IC601 STRF-6267 (genuine Sanken as supplied by Wagner AU)
C621 4.7uf 50v (Panasonic - power supply grade)
D623 D1NL20U (Sony part)
C851 1uf 350v (Nichicon PW series ultra high reliability)
PS603 Picofuse 4amps (Sony part)

Quality assurance:
• Study of the failure point to identify other components that need to be tested and verified before replacement are fitted. Lengthy process, revealed open circuit pico fuse but all other components tested as expected out of circuit.
• ESR testing showed C851 is due for replacement, when measured the incircuit peak inrush voltage is 177volts. Stock 450v rated polymer cap is failing and looks too physically small for what I would expect from Sony. Replacement is ultra high ripple current and reliability.
• Safety checks of voltage readings against the service manual table show good readings under load
• 1 hour reassembly ensuring cable loom is close to factory, strain relief in place, etc.
• Further testing show tube is capable of ultra high lumens output in 'dynamic' mode, akin to a flood lamp in a room (wow).
• Test patterns show excellent stability of geometry in dynamic mode as tested via S-Video NTSC source.
• TV reliably turns on and off via remote control with expected standby light.
• Degauss working as expected - not every power cycle as prior mentioned by customer but this may be a coincidence.

Soldering
• Cleanup of excess flux completed
• Full A and C board inspected under high optical magnification for dry or cracked solder joints

Rework of prior mod by eBay seller - Mega Drive 2 RGB Bypass. I will not post the before photos incase people mistake it for my handiwork!

Special thanks to Jeff of Sydney for investing in his monitor ///. This tube has a unique and rich forest green phosphor unlike anything else I’ve seen. Approx 3 hours work addressing cracked solder joints and lubricanting pots etc. “before” photo of one example where transistor has bad solder joints. No after photo sorry.