LDV4300D Cleaning
Before attempting any electrical calibration or modification of a laserdisc player it is important to ensure that the machine is mechanically sound. In addition , dirt and dust inside the player and around the optical assembly degrades performance. For best results from the duplication process it's important that the player is in the best condition possible.
In this guide I will walk you through the steps to disassemble the top-deck of the player so all mechanical parts can be inspected and cleaned.
You will need a Philips screwdriver, some nylon gear grease, an anti-static (ESD safe brush), some small cable ties, lots of kitchen roll (for wiping away old grease) and some hot soapy water to clean all the plastic parts. A soldering iron and some solder is also required as a switch needs to be removed and reattached as part of the disassembly and assembly process.
WARNING: Ensure that the player is disconnected from the mains power before removing any covers from the player! When working inside the player caution should be taken not to damage or dirty the optical assembly, keep all tools and removed parts of the player away from the laser optics.
Start by removing the top and bottom covers from the laserdisc player; simply remove the screws from the sides and back of the player and slide the lid about 1 cm backwards, then lift off. Flip over the player and remove all the bottom plate screws. Once all the screws are removed simply lift up the cover from the front of the player. Now flip the player back over to the top-side.
The next step is to remove the disc tray. The easiest way to remove the tray is to power up the player and hit the eject button so the tray is out of the player, then turn the player off and disconnect the power (if this isn't possible you will need to remove the tray eject motor - instructions for this are below). The disc tray is held in by two metal stops (one on either side of the tray) and a plunger shown in the following picture:
Remove the plastic stop from the plunger mechanism and then unscrew the metal plate. Also remove both metal stops from either side of the tray. The tray can now be removed by pulling the tray gently out from the front of the player.
Unscrew the four screws holding the crossbar in place and remove the crossbar:
Next remove the four screws that hold the front panel (there are three on the top and one underneath). The panel is also clipped on the top and bottom so you will need to unclip the plastic (carefully as the tabs are easily broken) and the front cover should drop away from the metal frame.
Once the front-cover is removed simply pull out the two connectors and the front-panel is completely loose.
After removing the front-cover remove the plastic T-piece from the power button shaft. The machine should now look like the following photograph:
To remove the front part of the frame start by unscrewing the two screws in the front of the drive:
Next remove the two screws holding the front frame onto the deck and the two screws on the underside of the player:
Finally remove the screw on the left side of the front frame and the matching screw on the right:
Note that the screws holding the front frame to the deck are shorter than the other screws; don't get them muddled up (note: this only seems to be true of some players; others have identical length screws).
Next we will remove the top gear and shaft from the tray loading mechanism which is held in by two copper-coloured screws:
To remove simply unscrew the two screws and lift the shaft up and out of the deck:
Now flip the player over and locate the tray loader module shown in the following picture. There is a single cable running to the mechanism; unplug it from the tray loader module:
Unscrew the 3 mounting screws from the tray loader mechanism:
The tray loader module should simply lift out. Now is a good time to check the loader belt for wear and replace if necessary.
Once removed the underside of the deck should look like the following picture:
Flip the player over to the top-side and slide the white locking plates towards the front of the player. Next remove the single screw holding the left-side frame in place:
The left-side frame should lift up and out of the player:
Now unscrew the four flanged screws holding the left-side of the tray assembly:
Remove the disc clamping mechanism from the plastic part of the deck. The plastic part of the deck should now be lifted free of the metal deck:
Removal of the right-side slide mechanism is a little more tricky as the power supply modules need to be moved clear of the frame in order to remove the mechanism. To begin with unscrew the sync input board from the back panel to allow you to move it to one side:
Next remove the screw in the back panel that secures the side frame:
Next remove the two screws from the voltage selection switch:
Remove the front and rear screws from the power input module:
Remove the four screws that hold the transformer in place and cut the two zip-ties that hold the cabling in place (be careful not to cut the wires):
Now that the transformer and power input modules are loose, unscrew the remaining power module. The left-side of the power module is held down by a small plastic lug. Once the screws are removed you can grip this with some pliers and carefully lift the board up and off the lug:
Now the power supply modules can be slid out of the way. If desired you can unplug the power modules and remove them completely, however this isn't necessary for cleaning the upper-deck. Next unscrew the three remaining screws holding the side-frame to the deck:
The two metal parts of the side-frame should simply lift out of the player:
Before removing the plastic slide mechanism care must be given to the two switches mounted on the deck. There is one switch that detects when the tray is closed:
and another that detects when the tray is fully open:
Remove both switches by unscrewing the copper coloured screw holding the switch in place. The tray closed switch can be pushed through the plastic frame but the tray open switch does not fit through the provided hole:
The safest thing to do is to simply desolder the switch for the time-being. Snipping the wires is not recommended as it will result in a shorter wire:
Once both switches are out of the way unscrew the 5 flanged screws holding the plastic part in place:
Once the screws are removed simply lift the plastic part away from the deck:
This completes the disassembly of the upper deck. The whole surface can now be cleaned free of dirt, dust and grease:
The plastic slide mechanisms have 4 separate parts. The metal sliders have 2 screws each which can be unscrewed to remove the part. The white plastic parts should be separated from the main part and should be in two pieces as shown below:
The front panel circuity is simply screwed to the plastic of the panel, remove all of the screws and lift out the main board. Once this is moved you will be able to remove the circuit board underneath:
With the circuit boards removed you can continue and unscrew the main panel buttons. The power button can also be removed but take care not to loose the two small springs:
For the metal parts you can use methylated spirits or similar to help remove the hard oil that covers the surfaces or even drop them in water and washing up liquid and scrub until clean. For the plastic parts remove as much grease as possible using kitchen roll paper (or similar) and then wash thoroughly in hot soapy water. After 20 years in the player the grease causes more friction than it solves, so it's a good idea to take your time and get everything as clean as possible.
You can clean any gears by firstly removing excess grease with kitchen roll paper and then using a small brush (soaked in methylated spirits or similar) to brush away the grease between the teeth of the gears.
A combination of brushing and wiping usually works well. Don't forget to give the surface of the top deck a clean too while all the parts are removed and the underside and sides of the disc tray itself. Finally clean the front panel in hot soapy water but be careful not to use anything abrasive that might scratch the surface of the panel. Leave all the parts to dry and then finish by rubbing down all of the surfaces with a lint-free cloth to remove any last residue of the original grease.
The reassembly process is, generally speaking, the tear-down process in full reverse. Here I won't go through step by step (as this is already covered).
To begin with place the right plastic assembly back on the upper-deck and reconnect the switches (you will need to resolder the front switch as it was disconnected earlier). Screw the plastic piece down using the flanged screws and then place the disc tray guide back in place at the front:
Next put the two metal side-frame pieces back in place and, working from back to front, reseat the power supply modules. Be careful to reconnect the power switch shaft in case it was decoupled during the disassembly process:
Next apply a liberal coating of grease (either nylon gear grease or Electrolube SPG is recommended - if using other grease, ensure it is plastic-safe) to the surfaces over which the slider slides. Also grease the lever on the underside of the white plastic slider. The slider simply drops into place. You should be able to slide it freely (and it will 'lock' when pushed forward - use the white lever to release it):
Next put back the left plastic assembly, grease and fit the slider, then reinsert the disc clamp with the white sliders towards the front of the machine. The disc clamp can be a little tricky to pop back into place but, once mounted, should move backwards and forwards in the sliders without too much force. Don't screw down the left plastic assembly until the clamp is in place, this makes it easier as you can tilt the assembly back slightly to get the clamp in place. Once it's all fixed in, screw it down to the upper-deck using the flanged screws:
Ensure that the disc clamp moves up and down correctly when the sliders are moved. When the sliders are fully forward they lock in place. Use the two levers to release the slider and move it backwards. The following picture shows the clamp engaged with the sliders fully forward:
Next place the left side-frame back in place and screw it down using the screw located at the back-left of the player. Make sure you insert the metal piece directly downwards as there are some small plastic tags that hold it in place (and you'll snap them off if you try to swivel the side frame into place):
Next ensure that the gears of the loader module are greased, then flip the player over and mount the module back into the player. Don't forget to reattach the control cable to the module:
Now reassemble and grease the tray loader shaft and place into the slots provided by the upper-deck. The shaft is hooked in under some plastic tabs at the back and screwed in place at the front:
Now put the front-frame back on the player. Don't forget the two screws under the player:
Next place the cross bar back in place and affix with four screws:
Before putting the front panel of the player back in place make sure you pop the small plastic piece onto the switch shaft:
Reconnect the two cables to the front-panel and attach by gently locking it in place using the top tabs and then the bottom. Then screw in the 3 mounting screws to the top:
If you have the confidence (and the correct materials) now is a good time to clean the laser optics. Don't use a cotton bud for this (seriously - don't). Use the correct materials such as an optic prep cloth or chamois tips (or equivalent). Using the wrong tool for the job here could result in degraded performance. Get the right stuff or just leave the optics alone!
To slide in the tray you have to ensure that the loader shaft is in the correct position. Rotate the shaft until you see a 'half-tooth'. This half tooth should be positioned a few degrees from straight-up, towards the front of the player. If this is in the right position the tray will slide in easily. If you need to use any force, you have not lined up the shaft correctly. Once the tray is back in place reattach the two stops and the plunger mechanism. Don't forget to tighten the two screws that engage with the stops (on the front frame):
That's it; the player is ready to go! Well, you might want to put the cover back on the top and bottom, but if you know what you're doing you can leave them off and admire the silky-smooth action of the player as it loads and ejects discs:
Note: the standard player has green LEDs; the player in the picture above was modified (because I thought the red lights looked better!).
Servicing the laserdisc player every few years will keep your player running much smoother and greatly reduce the risk of mechanical failure. The grease (after nearly 20 years of heat and dust) becomes too sticky. As the viscosity of the grease increases it gradually causes more and more friction and makes the various mechanism have to work harder to get the job done. In addition, the dust, dirt and other debris is whipped around the player by the air vortex generated by the spinning disc, causing it to dirty the discs and (even worse) foul the optics in the player. Cleaning will reduce drop-outs and tracking problems overall. A clean player is a good thing!