/Sony-SSM-14NXX-SSM-20NXX-RGB-Modification

A guide on how to modify your Sony SSM-14NXX or SSM-20NXX Monitor to support RGB

SSM-14NXX / SSM-20NXX RGB Modification

Overview

The purpose of this document is to explain how to modify a Sony SSM monitor to be able to support RGB. As a disclaimer, I am not an electronics engineer by any means, and all of the information contained within is collated from various sources online. This documentation is mostly for my own reference, but I do hope others find it useful too. While I have done this modification myself, I was standing on the shoulders of others the whole way.

Please note that there are actually multiple ways to achieve this mod, and that the more correct way is almost definitely to populate all missing components, but this documentation serves to outline the specific route that I took to achieve it.

Who this guide is for

This guide is specifically for you if you own any of the following monitors, and wish to modify them to accept RGB:

14" Models 20" Models
SSM-14N5A SSM-20N5A
SSM-14N5E SSM-20N5E
SSM-14N5U SSM-20N5U

PVM models

This guide may also be useful to you if you own any of the monitors from the table below, as they are also based on the same chassis as the aforementioned 'SSM-XXXXX' monitors.

14" Models 20" Models Notes
PVM-14N5A PVM-20N5A Moddable - see notes below
PVM-14N5E PVM-20N5E Moddable - see notes below
PVM-14N5MDE -- Moddable - see notes below
PVM-14N5U PVM-20N5U Moddable - see notes below
PVM-14N6A PVM-20N6A This monitor already has RGB
PVM-14N6E PVM-20N6E This monitor already has RGB
PVM-14N6U PVM-20N6U This monitor already has RGB

Modifying the PVM models is slightly different, and perhaps even easier depending on your perspective. The mod differences specific to PVM models that I am aware of are:

  1. Important - Your PVM may or may not have a connector and wiring harness pre-installed at connector CN403 on the A board. If your monitor does not have this connector + harness, then you will need to route your own wires between the A and Q boards, but be aware that Sony made a mistake with the PCB labelling for this connector and it is reversed. On the PCB, the red pin is labelled as being closest to the front of the monitor, but the red pin is actually the one closest to the corner of the PCB; all other inputs are respectively reversed too. Therefore, from the corner of the PCB to the front, the pinouts are: R, GND, G, GND, B, GND, and Audio. See the images section below for a picture with the corrected pinout.

  2. You may not need to make the same jumper cuts on the A board as noted in the instructions below, as they may already be absent.

  3. The BA7604N and MC14052BCP ICs may already be present on your model, which means you will not need to add them.

  4. If your monitor already has a connector and wiring harness between CN402 on the A board and CN1302 on the Q board (which it likely will if your monitor has Line B), then you can route your RGB sync pin to the emitter pin at Q1312 which is equivalent to jumping a wire to ESYNC at CN1302. See the images section below for a picture showing where to make the connection.

  5. In the case of the PVM-14N5MDE, you may not need to add the 10 ohm resistor at R032, as it may already be present.

Image Notes
As per point 1 above, this image illustrates the corrected pinout for CN403. If you are wiring CN403 yourself because your PVM does not have a connector and wiring harness, keep this in mind. If you want to install your own pin header (as opposed to just soldering wires directly into the PCB holes), the type of header you need is one with a 2.54mm pitch.
As per point 4 above, if your PVM already has a connector between CN402 on the A board and CN1302 on the Q board, you can put a jumper wire between these two points instead of running a wire between A board and Q board which is necessary for models without aforementioned wiring harness between CN402 & CN1302.

Tools List

Required

  • Screwdriver
  • Soldering iron (I used a TS100)
  • Desoldering braid / Desoldering tool
  • Solder (I used 0.7mm)
  • Insulated wire

Highly Recommended

  • Multimeter
  • Flux
  • Side cutters

Parts List

Component Description Qty Links
Ceramic capacitor Surface mount, non-polarised - 0.1µF 3 Digi-Key - 445-1418-1-ND
Resistor Through hole - 75 ohm 0.25W 6 Digi-Key - S75CACT-ND
Resistor Through hole - 10 ohm 0.25W 2 Digi-Key - CF14JT10R0CT-ND
Switch Side actuated, through hole, right angle 2 Digi-Key - P12233SCT-ND
BNC Connectors Female socket 4 Digi-Key - 2057-RF1-106-D-00-50-HDW-ND
Jaycar - PS0658 (Australia)
MC14052BCP Integrated circuit 1 eBay
BA7604N Integrated circuit 1 eBay

Step 1 - Dismantling the monitor

A note on safety: It goes without saying that working on CRTs has an element of risk as high voltages are involved. You can get a nasty zap or worse if you are not careful. There are lots of guides on YouTube on CRT safety and how to discharge them. I encourage you to educate yourself further on CRT safety so you're prepared for doing this mod.

At the high level, dismantling the monitor for this modification involves the following steps:

  1. Removing the case
  2. Removing the Q board (i.e. the panel + PCB with the connectors on it), and releasing the Q board from the connector mounting plate
  3. Removing the A board (i.e. the main board that sits at the bottom of the monitor)

Step 1.1 - Removing the case

  1. Remove the 4 screws (2 per side) on the sides of the monitor.
  2. Remove the 4 screws on the rear of the monitor, all of which are located near the bottom. Two on the outer perimeter of the case, and two on the connector panel.
  3. Using the carry handles, pull the outer case off to the rear.

Step 1.2 - Detaching the Q board and releasing the Q board from the connector mounting plate

  1. Looking at the rear of the monitor, note that there are markings that suggest that you need to push down on the plastic frame below the input board.
  2. Gently press down in the designated areas while pulling the Q board outward to release it.
  3. This procedure is best illustrated in Steve @ Retro Tech's video here.
  4. Disconnect the ribbon cables and ground wires.
  5. Using a soldering iron + desoldering braid, or a desoldering tool, desolder all of the points where the Q board attaches to the connector mounting plate. Note that this includes 4 ground tab sections on the perimeter of the board.

Step 1.3 - Removing the A board

  1. Take a note / photo of all the connector locations.
  2. Discharge and remove the anode cap. An example of how to remove and discharge the anode cap for PVM's is illustrated and explained in Steve @ Retro Tech's video here. You may also wish to review this video if you prefer to use the discharge tool method.
  3. Disconnect the remaining connectors.
  4. Hold the A board firmly at the back and pull it outwards. There are no screws or tabs holding it down.

Step 2 - Q board and mounting panel modifications

Now that the Q board has been released from the mounting plate, you can add the required components. I did it by first adding the BNC connectors to the mounting plate and soldering wire into the solder cup terminals which I then fed through the appropriate holes in the Q board. I then used insulated wires on the BNC ground lugs that wrapped around and attached to a single ground terminal on the Q board / mounting plate.

Action Part Location / Notes
Add component 75 ohm resistor R1339
Add component 75 ohm resistor R1344
Add component 75 ohm resistor R1346
Add component 75 ohm resistor Tieing BNC pin directly to ANA-R at CN1303. You can attach to the emitter pin at Q1308
Add component 75 ohm resistor Tieing BNC pin directly to ANA-G at CN1303. You can attach to the emitter pin at Q1309
Add component 75 ohm resistor Tieing BNC pin directly to ANA-B at CN1303. You can attach to the emitter pin at Q1310
Add component Insulated wire Tieing the Sync BNC pin to EXT SYNC at CN402 on A board
Add component Insulated wire Optional - Tieing AUDIO at CN1303 to emitter pin at Q1305

The optional jumper wire for the Audio means that the RGB and Line A will share the same 'Audio In' jack.

Q board and mounting panel modification images

Image Notes
Q board, showing all component modification locations.
Q board, showing an example of how to attach the BNC connectors.
Q board and A board, showing an example of how to connect the sync wire.

Step 3 - A board modifications

Modifying the A board is pretty straight-forward. It's just a matter of removing and adding a few components. As noted earlier, some of these changes are not necessary if you are modifying the non-SSM variants based on the same chassis.

Action Part Location / Notes
Remove component Jumper wire JW401
Remove component Jumper wire JW402
Remove component Jumper wire JW403
Add component 10 ohm resistor R030
Add component 10 ohm resistor R032
Add component SMD capacitor C310
Add component SMD capacitor C311
Add component SMD capacitor C312
Add component MC14052BCP IC401
Add component BA7604N IC402
Add component Tactile switch S006
Add component Tactile switch S008

A board modification images

Image Notes
A board, showing all component modification locations.
A board, detailed image showing where the ICs and jumper wire cuts / removals are to be made.
A board, detailed image showing where to attach the SMD capacitors.
A board, detailed image showing where to attach the 10 ohm resistors.
A board, detailed image showing where to attach the tactile switches.

Step 4 - Case / enclosure modifications

You will need to make some minor finishing touches to the case. Specifically:

  1. Cutting holes in the rear panel plastic so the BNC connectors can poke through. One way you can do this is by using a scalpel to cut a rough but slightly smaller diameter circle out from behind and then roll up some 240 grit sandpaper and sand down the remaining overlap.
  2. Cutting holes in the front panel plastic so you can reach the tactile buttons used for switching between your two inputs (Line A and RGB).
  3. Adding labels for your new inputs and buttons.

Case / enclosure modification images

Image Notes
Rear panel, showing an example of how to modify the rear panel.

3D-printed front panel buttons

If you have access to a 3D printer, then you can print yourself some face buttons using the STL file here: https://www.thingiverse.com/thing:5029004. The STL file is also available on this GitHub page in the '..\Faceplate Button' directory. Kudos to 'galaxius' for kindly designing and printing the buttons for my own modified monitors.

Alternatively, for a small fee, I can provide you with two 3D printed buttons for switching between RGB and Line A. If you are interested, you can drop me an email: oo2@outlook.com. The cost is $5 AUD + shipping for 2 buttons. I can also sand and paint them for you for an additional $5 AUD - I will paint them with three coats of Tamiya Acrylic.

If you are using the suggested switches (or ones with very similar dimensions), the 3D printed buttons should remain captive in the hole and rest neatly against the switch acutator. Note that you will still need to punch or cut a square hole in the vinyl sticker so the button can protrude through.

Image Notes
An example of how these buttons can look once they are installed after the necessary modifications are done to the vinyl sticker.
Buttons unpainted / unsanded.
Buttons painted / face sanded.
Button video - view from inside case.
Button video - view from front (unsanded + painted prototype button)

Reproduction faceplate decals

With gracious thanks to Industrial Designer, Evan Twyford, we now have templates for creating reproduction faceplate decals to suit monitors with the following configurations:

  • Modified monitors with 7mm x 7mm button holes for Line A, and RGB. Suitable for monitors using 3D-printed buttons available on this GitHub page - Note: currently untested - if you have created a panel with this configuration, please let me know your results!
  • Modified monitors with 10mm x 10mm button holes for Line A, and RGB. Suitable for monitors where you have your own solution for faceplate buttons and / or desire the original 10mm x 10mm hole.
  • Original N6 monitors with 10mm x 10mm button holes for Line A, Line B, and RGB. Suitable for monitors where Line B is also present, as is the case for original, unmodified N6 models.

The decals are available on this GitHub page in the '..\Faceplate Decals' directory. As advised by Evan, the PDF drawing will have just about all the info you need to know to have these decals recreated. Separate DXF file for the die-cut pattern is also provided if needed, but it is included in a layer in the PDF.

If you are based in the US, you may find the following information provided by Evan regarding printers / vendors useful:

  • Gamma Ray Graphics - cheaper option (~$20 ea), colour matching not perfect, thinner labels.
  • MPC - Metalphoto of Cincinnati - $400 setup cost, polyester nameplates are an accurate reproduction. This company, or similar, should have no problem meeting OEM spec.
Image Notes
An example image provided by Evan Twyford showing 2 PVM-14N6U monitors with reproduction faceplate decals produced by Gamma Ray Graphics

References and acknowledgements