Philips VP406 LaserDisc Player Repair

Philips VP406 Repair
[[|border|frameless|220px|center]]
Primary Contact	Aaron / Tim
Created	2025-03-26
Completed	{{{completeddate}}}
Dormant	{{{dormantdate}}}
Version	{{{version}}}
Members	Tim, JonW, Ali, Olivia, Aaron
Manufacturer	{{{manufacturer}}}
Model	{{{model}}}
Location	[[{{{location}}}]]
GitHub / Repo	{{{repo}}}
Status	{{{status}}}
Type	Undefined
Live Status	{{{livestatus}}}
QR code

We're trying to fix a VP406 LaserDisc player. It lived under Tim's bed for many years and now we want to watch LaserDiscs during film night - but first, we must repair it. While the disc plays, and the TV syncs correctly, the video is offset. The issue appears to be before or around the PAL demodulator, since the on screen debugging menu is correctly positioned.

26th March 2025

• Video plays, but is offset
• Power switch doesn't work - removed and bridged temporarily
• X2 RIFA capacitor exploded - removed

• 
• 
• 
• 
• 
• 
• 

29th March 2025

• Removed the other X2 capacitor, since it was probably also going to explode.
• Lots of debugging. We think the issue is not with Board A but Board D, which presumably creates a line pulse but out of phase from the video.
• Confirmed that the video feed going into the PAL modulator is alight, since the TV can sync to it.

What we want to check next:

• Verify that HMANCH is being generated correctly by probing CVTDM and HMANCH at the same time (see page 44 of schematic). They should line up.
• Check that HMANCH isn't being inverted in some weird way by the "SLAVE SOURCE" (see page 34)

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
•