Modern Digital TV's are now Computers with a CPU & Memory etc. Prone to various component problems.
But.... the biggest & most likely problem is that the DC voltages are not stable
Caused by Leaky or Bulging Electrolytic Capacitors
Do you have access to a Soldering Iron?
Do you Have Access to an Electronic Components shop?
If you are not a Tech Type....
Take it to a service tech & ask to check Electrolytic Caps.
Most Tec's these days will Just Do A Board Swap. Costing $$$
If you are a tech type and feel like exploring & fixing the problem.
Disconnect The Power
No Internal 25KV voltages to worry about.
There is a shock hazard on AC side of Switchmode Board.
Electro Caps on AC side can hold 110 / 240v
Check Switchmode internal power supply on DC Side for bad Electrolytic Type Capacitors.
The insulated Tin Cans on the PCB
Bulging or leaky Electrolytic Caps cause many failures in modern digital TV's
You need to align the optics mechanically. If you changed the dlp chip and its not centered then the chip is not shimmed properly or the reflection mirror behind the lens needs adjustment. You should get a service manual for that chassis and follow the directions. there may be an electronic method but I am not aware of one.
Your repair tech hinted correct. Although the bad connection will likely be in the power supply, it actualy can sit everywhere the power goes. Can be anordinary plug / connector with a little oxidatin, or a dab soldering point. Or perhaps a electrolitic cap, slowely dying.
Let the tech do his job. He has the tools, education and skills to keep your beloved TV alive.
Hello, contact Mitsubishi, they are sending out the chip at no charge to repair the problem, but they do not include the labor. if you are handy, there is a video on how to do it, otherwise when you receive the part contact a repairman. If they know what their doing, they should be able to do it there for around $100-$135.....tks