Troubleshooting Guide – The Renard SS24
This is NOT the official Troubleshooting Guide for the Renard SS control boards
For the official Guide, follow this link.
Troubleshooting Guide - The Renard SS24
WARNING!!!!!
This guide has NOT been checked by anyone who knows anything about electronics! The original author is NOT versed in all things electronic. This document is in a DRAFT status, is NOT COMPLETE, and could be COMPLETELY WRONG. Following any of these steps may at best kill your board, or at worst KILL YOU! ALWAYS use best safe practices when working with electricity!
Background
The Renard line of lighting controllers, especially the SS series are elegant in their simplicity. Since they are so simple, any problems with them can be usually found with nothing more than an ammeter. Before jumping in however, you may need to brush up on a few concepts. For those of you with experience in electronics, these explanations may not be entirely accurate. Since the audience for this article typically doesn't have a lot of knowledge about electronics, some concepts have been greatly simplified.
A typical Ren SS board is divided into 5 separate sections: Low voltage (Logic) power, Logic, Zero Cross, Communication, and High Voltage switching.
The voltage section consists of a transformer, rectifier, capacitor, and voltage regulator. The transformer takes line voltage (120V here in the USA), and converts it down to 12V AC. From there, the power travels through a rectifier circuit which takes the AC power and turns it into the DC (Direct Current) power the logic will need. The large capacitor on the board acts much like a battery. Should the current coming from the transformer fall too far, for instance because there was a large draw on the AC line, the capacitor can (for a short time) take up the slack. From there the power travels through the LM7805 voltage regulator. The voltage regulator, as it's name implies, regulates the voltage coming out of it to a nice stable 5V DC. The LM7805 also acts to protect the circuit since it is built to withstand over-current draws and short circuits. Power coming from the LM7805 is used to drive most all of the other 'on-board' functions, IE Communication, Logic, etc.
The low voltage after the voltage regulator has 2 or more capacitors: an electrolytic at C2, and one each near the PIC chips. Again, these capacitors are there to temporally boost the current to various ICs in case there is a larger momentary draw.
The Zero Cross section consists of a single part, the H11AA1 optoisolator. AC power is a wave that has a positive and a negative component. Each channel of the Renard board can be said to be a solid state dimmer. If you want to dim a light by 50%, you only need to turn on the channel for 50% of the AC wave. 75% brightness = 75% of the wave, etc. In order for the logic to turn the channel on and off at the proper time, it needs to time the wave. The H11AA1 opto sends a pulse to the logic each time the wave changes from positive to negative and back - i.e., it crosses zero.
The logic consists of one or more PIC processors, and a timing signal generated by the clock crystal. The PIC16F688 is a fully functional computer which has several inputs (from the communication and zero cross section), and outputs - nine of them to be exact (eight for the dimmer channels, one for transmitting data to the next PIC). Each of the eight dimmer outputs is tied to eight separate channels. The program running on the PIC (sometimes referred to as 'the firmware') listens for commands coming from the communication section, and if a command is for one of the channels under it's control, it turns it ON, with the correct frequency or OFF.
To turn on a channel, the PIC waits for a Zero Cross signal. Once it has the zero cross, the PIC begins to count by listening to the pulses from the clock crystal. When the exact amount of time has passed in the AC wave, it turns the channel on. For instance, if you have a channel on at 50%, it counts until 1/2 the AC wave is over and then turns the channel on, making the light appear to be at 50% brightness. If you have a channel on 100%, it immediately turns the channel on. The PIC continues to do this until it gets another command from the communication section to turn the channel off.
The PIC controls the channel by simply tying the appropriate output pin to ground. When a channel is off, the output pin is left high, so that there isn't enough current flowing through the optoisolator input to turn it on. When the channel is on, the PIC internally connects the pin to the board ground completing the circuit. The optocoupler (more on them later) for a channel is always supplied +5V - this is much like wiring a wall light switch where the hot is coming FROM the bulb instead of to it.
The SS series has from 1 to 3 PICs on-board, depending on the number of channels that board controls. The SS8 has 1 PIC, SS16 has 2, while the SS24 has 3. For the SS16 and SS24, each pic controls a group of 8 channels. Channels 9-16 are really nothing more than channels 1-8 which are controlled by PIC #2, while for a S24, Channels 17-24 are channels 1-8 controlled by PIC #3.
Each PIC has 14 pins:
| Pin | Function |
| 1 | + Power |
| 2 | Clock In |
| 3 | Channel 1 |
| 4 | Zero Cross |
| 5 | Data In |
| 6 | Data Out |
| 7 | Channel 8 |
| 8 | Channel 7 |
| 9 | Channel 6 |
| 10 | Channel 5 |
| 11 | Channel 4 |
| 12 | Channel 3 |
| 13 | Channel 2 |
| 14 | - Power |
If a command received by the PIC is not for the channels it controls, it sends the data back out pin 6 to the next pic, or the communications section.
The communication section consists of 2 RS485 chips, 2 RJ45 connectors, a DB9 connector, a connection to the clock crystal, and assorted resistors and diodes. The input communication section takes the incoming data from the Rj45 connector or the DB9 connector, filters it a bit, then passes it on to the first (or only) PIC on the board. The second RS485 chip takes any outgoing data from the last (or only) PIC and sends it out the door through the other RJ45. Jumper JP2 controls where incoming data comes from (ON for RS232/DB9, OFF for RS485/RJ45).
The high-voltage switching section is where all the work takes place. This section consists of a resistor, a opto coupler, another resistor, and a triac. The resistors in this section are there to ensure the other two components don't draw so much current that they damage themselves or other parts of the circuit.
Think of the optocoupler as an insurance policy. It's job is simple: to electrically isolate one circuit from another. The optocoupler is nothing more than an infrared LED and a receiver in the same package. The optocoupler changes the signal on one side into infra-red light, then immediately back into an electrical signal to go out the other side. Now you can see how it gets it's name: it OPTICALLY (optic = with light) COUPLES (ties together) 2 circuits together. Why would you want this? To prevent high voltage from getting back into your computer, and to prevent ground loops. Without the optoisolators the AC hot or neutral would end up being connected to the low voltage logic in your circuit, which is not only a major safety hazard but may also damage the circuitry in the controller or in your computer.
The last section is the High Voltage section. It consists of the triacs and the terminal strips.
The job of the triac is simple: It's a switch that allows us to control the high voltage of the channel, by using the low voltage of the control logic. In it's simplest form, a triac can be thought of to have 2 high voltage pins, and 1 low voltage. One pin is supplied the mains voltage (in the USA that's the 120V feed). The other high voltage pin is the output. The low voltage pin is what signals the triac to turn ON, and is called the 'Gate'. The high voltage output is of course tied to the terminal strip. This is the area on the board where you hook up your lights.
Troubleshooting your Ren SS board
These troubleshooting steps assume that you have used the 'Beginner's Setup Guide', and that you have a test that has failed. If you are having problems with a board and have NOT followed the steps in the beginners setup guide, do so now.
All directions assume that you are looking at the side of the board with the components installed.
The BOTTOM of the board is the long edge with the terminal strip(s) The TOP of the board is the long edge where the RJ45 jacks are installed The LEFT side of the board is the short edge closest to CH1 The RIGHT side of the board is the short edge closest to the HIGHEST channel on the board (CH8, CH16, or CH24 depending on which board).
When testing continuity, it's best to test from the component side of the board, ABOVE the pad needed. For instance, when checking continuity to a resistor, check from the leg of the resistor that is ABOVE the board to the leg above the board of the next component. Doing it this way will ensure that you are not only testing the trace, but the pad as well as your solder connection. When using this method, just be sure that where you are touching the probes isn't insulated. Your probe should be touching bare metal, and not something that looks like paint.
Logic Power
No POWER LED
No 5V at test point
Is the board plugged in? Ensure you have a power cord properly installed. For SS16 and SS24 boards, the power cord should be hooked up to the LEFT side of the board.
Is the fuse installed or blown? Unplug the board and check the fuse on the left side.
Is the Rectifier circuit installed correctly? Check D1,D2,D3,D4. These parts must be installed with the silver stripe facing LEFT.
Is C1 installed correctly? C1 must be installed so that the BLACK stripe (which has a '-' sign in it) faces RIGHT.
Is U1 installed correctly? U1 must be installed so that the heat sink is toward the TOP of the board. Check the +5V test point to ground. Do you now have +5V DC? If not, continue below
If there is 5V at the test point and the power LED is NOT lit:
Is the POWER LED installed correctly? the flat side of the LED should face the TOP of the board.
Is C2 installed correctly? C2 must be installed so that the stripe (which has a '-' sign in it) faces the TOP of the board.
Unplug the board. Check for continuity from the TOP pad of the LED to ground. If OK: Starting from the bottom pad of the LED, follow the traces on the board and check continuity between pads. When the continuity check fails, you have a bad solder point or lifted pad. Repair it and start testing again.
Still no power at the +5V test point
Check the LEFT pin of U1 to ground, you should see a voltage higher than 5V. If there is voltage, check the solder connections on U1 to ensure they are good and there is no broken pad. If all is OK, assume U1 is dead and replace it.
If there is no power at U1, check for voltage at the + side of C1 (left pad) and ground. If there is voltage, check solder connections. If they are good, assume C1 is bad and replace it.
Check for **AC** power between the left side of R1 and the N terminal of 120V connector (use the screw). If there is NO AC power at R1, check solder connections on the transformer. If the connections are good, assume the transformer is bad.
If there is AC power at R1, assume the rectifier circuit is bad. Check all solder connections on D1-D4. If good, replace D1-D4.
Status LED problems
At this point you should at least have a power light on the board. If not, follow the 'Logic Power' troubleshooting steps.
Install a jumper on JP3, plug in the board, and follow the steps in the beginners guide to test each LED.
NO or only some LEDs light
Is JP3 installed? Is RN1 installed correctly? RN1 must be installed so that the dot faces LEFT Are the LEDs installed correctly? the flat side of the LED should be installed facing the BOTTOM of the board
Unplug the board. Check for continuity between: GND and Pin 14 of U6 Pin 1 of U6 to +5V Test point Pin 1 of U6 to top of C3 top of C3 to left side of JP3 right side of JP3 to Pin 1 of RN1 Follow the traces from any LED that doesn't light back to RN1 and check continuity.
If continuity is good and there is +5V at pin 1 of RN1, assume the LED is bad. If after replacing an LED it still doesn't light, assume RN1 is bad.
Channel problems (jumpered, not via Vixen)
First, check the most common problems: Ensure you have a power light on the board, and that you have tested all the status LEDS. If not, follow the Beginners guide until you get to the steps testing each channel.
Ensure F1 and on SS16/24 F2 has not blown.
Are the optocouplers installed correctly? The small white dot on the MOC3023 MUST face RIGHT (the lettering on the chip should be upside down)
Are the Triacs installed correctly? The heat-sink must be aligned with the white line on the board. On SS16 and SS24 boards, the Triacs are in 2 rows and the heat-sinks face each other.
A range of channels don't work
If you have an SS16 board and channels 9-16 are not working, or if you have an SS24 and channels 13-24 are not working, first ensure that you have a power cord hooked up to the RIGHT side of the board and that it is plugged in.
If you have an SS16 or SS24 board, check to see if all the channels are out in each of the following ranges (ensure you have 2 power cords hooked up and plugged in):
1-8 / 9-16 / 17-24 (SS24 only).
1-8
If all channels from 1-8 are out (but others are working), be sure you have tested the status LEDs using the beginners guide. Pay particular attention to the connection between pin 14 and GND.
9-16 / 17-24 (SS24)
Channels 9-16 are controlled by U7 and 17-24 are controlled by U8.
Unplug the board. Ensure that: C2 is installed correctly. C2 must be installed so that the stripe (which has a '-' sign in it) faces the TOP of the board.
Check continuity from Pin 1 of U7/U8 and +5V Pin 14 of U7/U8 and GND
If either test fails, inspect the solder joints. If the +5 test fails, follow the traces back from Pin 1 and check continuity fixing any problems along the way. Continue with the 'Some Channels Don't Work' section starting with the lowest numbered channel if there are still problems.
Some channels don't work
Determine which channel is not working. Each channel on your board consists of (working backwards): a terminal block, a triac, a resistor, an opto coupler, a resistor, a specific pin on a specific PIC.
For SS8 boards, The triacs are in order from left to right, starting with channel 1. For SS16/SS24 boards, The top row of Triacs controls the ODD numbered channels (1,3,5,7,9,11,13,15,17*,19*,21*,23*), the bottom row controls the EVEN numbered channels (2,4,6,8,10,12,14,16,18*,20*,22*,24*) *=SS24 only. Locate the triac that controls the channel that is out.
Above the triacs is a row of resistors. The left most one is for channel 1, and they run in order up to channel 16 or 24
Above that row of resistors are the optopcouplers (6 pin devices), again they start at #1 on the left and run up to 16 or 24.
Above that is another row of resistors. Again, they start with #1 on the left and run up to 16 or 24.
From there, the resistors in groups of 8 go to the PICs. Channels 1-8 are on U6, Channels 9-16 are on U7, and 17-24 are on U8.
| Channel | Pin | ||
| U6 | U7 | U8 | |
| 1 | 9 | 17 | 3 |
| 2 | 10 | 18 | 13 |
| 3 | 11 | 19 | 12 |
| 4 | 12 | 20 | 11 |
| 5 | 13 | 21 | 10 |
| 6 | 14 | 22 | 9 |
| 7 | 15 | 23 | 8 |
| 8 | 16 | 24 | 7 |
Is the optocoupler installed backwards? The white dot must face RIGHT (the lettering on the optocoupler will be upside down).
Power off the board and remove the optocoupler, replace it with a known working one. The optocoupler is bad if the channel begins to work.
If not, unplug the board again and check for continuity on the out channel, fixing any problems along the way:
From the + side of the terminal block to PIN 1 of the triac (Pin 1 is on the left when looking at the triac such that you can read the markings) From the N side of the terminal block to the n side of the input terminal block From the top fuse holder (SS16: F1 for channels 1-8, F2 for channels 9-16. SS24:F1 for channels 1-12, F2 for channels 13-24), to the middle pin of the triac. From Pin 3 of the triac to the bottom of that channels resistor above it. From the top of that resistor to pin 4 of that channels optocoupler From pin 1 of the optocoupler to the right side of the resistor above it From pin 2 of the optocoupler to the correct pin of the correct pic (see table above) From the left side of the resistor to +5V
If the channel is still out, assume the triac is bad and replace it. If the channel still does not work, replace both resistors.
Zero Cross/Diagnostic PIC Problems
At this point, with the exception of the Zero Cross and Communications sections your board should be working perfectly. Install a beta diagnostic pic in U6, install a jumper on JP3, and plug the board in. All the diagnostic LEDS should light then go out, followed by each one lighting in sequence (there may be a delay between some LEDs lighting). This will repeat 3 times to be followed by flashing HB and ZC lights.
Ensure that you have performed all the manual tests of the status LEDs. If you have not done so, do it now.
Always unplug the board before removing/installing a PIC
If none of the LEDs light: Check that JP3 has a jumper on it. Check that none of the legs of the PIC have bent under or are not seated properly in the socket. Reprogram the PIC with known good beta diagnostic firmware. Verify the PIC in the burning software and re-install it. Replace the PIC with another and re-test. The PIC is bad if the new one works. Check continuity between the top of C3 and Pin 1 of U6. Ensure that the clock crystal U3 is installed correctly. The square edge of the crystal should be at the TOP LEFT.
The HB LED stops blinking
Reprogram the PIC with known good beta diagnostic firmware. Verify the PIC in the burning software and re-install it.
Replace the PIC with another and re-test. The PIC is bad if the new one works.
If HB again stops blinking, check for continuity between: (clock crystal/pin 2)
The ZC LED doesn't blink/stops blinking: Is U2 installed correctly? The Dot/Notch MUST face the TOP of the board.
Unplug the board, remove U2, and check for continuity between (fixing any problems found):
- Left side of D1 and Left side of R1
- Left side of D2 and Left side of R2
- Right side of R1 and Pin 1 of U2
- Right side of R2 and Pin 2 of U2
- Pin 5 of U2 and bottom of R9
- Bottom of R9 to Pin 4 of U6
- Pin 4 of U2 and GND
If all checks out, assume U2 is bad and replace it. If the ZC light again stops, assume U6 is bad and replace it.
It is possible to check the other channel banks with a diagnostic pic for SS16 and SS24 boards. Replace U6 with a PIC programmed with production code. Place a beta diagnostic pic into U7. Hook up 8 sets of lights to channels 9-16. Ensure that the board has 2 input power cords and plug them both in. The lights should react the same as the LEDs do for U6: All the lights should come on, then go out, followed by each channel lighting in sequence. This will repeat 3 times, at which time CH2 (HB) and CH6 (ZC) should start flashing.