Amplifone Deflection Board Guide 1.0 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>Disclaimer<<<<<<<<<<<<<<<<<<<<<<<<<<<<< Working on monitors can be dangerous. I take no responsability for any damages incurred to person or property through use of this document. If you are unfamiliar with working on monitors and high voltage systems, I suggest getting someone who is. Do not risk damage to yourself or your equipment. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< This document may be freely distributed, but not for profit or personal gain. I make no warranty for the information in this guide. Copyright (c) 2000 by Michael Kelley. Introduction This guide is not near the size or scope of the Amplifone HV Guide. Amplifone deflection boards were designed VERY well. In my opinion, much better than the WG 6100 deflection boards. Deflection transistor failures and failures in the low voltage section are rare. They become almost non-existant when the boards are modified with the upgrades in this guide. I know of two friends who have installed revised versions of the LV2000 to replace the low voltage section of the Amplifone deflection board. However, I don't feel that they are necessary on the Amplifone. (Thanks to Anders and Jeff for making the LV2000 for the WG 6100! It is a "must have" for any WG6100.) I have only seen the LV section of an Amplifone deflection board fail once in the past 17 years, and the failure was not the fault of the design. There is no history section here on the Amplifone deflection board. I really know nothing of its history, any info you can provide would be great. I've even tried searching for the patents on the Amplifone monitor with no luck. Please contribute anything you might have. It would be great to add a History section to this guide like the one in the Amplifone HV guide. Please let me know if you have any suggestions to improve this guide. Many helped make the HV guide better. I'd like the same to happen to this guide. You can e-mail me at mkdud@aol.com if you have any additions, suggestions, or corrections. I'd like to give thanks to these people for helping me: Randy Fromm, Gregg Woodcock, Joe Welser, Jess Askey, Ed Henciak, and Jack Hammond. Deflection Board Revisions, Schems I've only seen 2 variations in the deflection board design. It seems that the very early ones did not include X and Y size 10k pots located at the junction of R1&2 (y size) and R24 &25 (x size). These early boards were used in Amplifone equipped Gravitar & Space Duel (VERY rare), as well as all Quantum machines. I'm guessing they just figured to use the game board pots to adjust the x and y size. There are some early boards (serial #'s under 1000) with the RGB drive and bias pots arranged differently than the later boards. Most of these were boards without the x or y size controls. If you have a board without the size pots, you can add them if you want. The pots are 10k, and they can be mounted on top of resistors R1&2, and R24&25. You will want to see the Amplifone Schematic (Thanks Jess!) at Gamearchive: http://www.gamearchive.com/video/manufacturer/atari/vector/monitors/amplifone/amplifone.pdf I've seen deflection boards in beige, blue, and green colors, but the only differences were those mentioned above. 1. Remove & Replace all Jumpers The first thing I do when repairing any Amplifone defelction board is to remove all of the "zero ohm" brown jumpers. They are as evil and malicious as the red HV transformer on Amplifone HV boards. However, they are much less costly and are easier to replace. These are located at any spot on the board where you notice a "W" designation. They are brown, and almost look like resistors. You will find W1 through W8 on the deflection board. I suggest using around #4 - #6 wire to replace them. I usually save clipped leads from components for doing this. Notice how many of these *@%$# jumpers crumble and break when you heat them to take them out? I HATE these damn jumpers! MANY times I've seen these cause deflection and HV board problems. You might test them, and they'll ring out just fine at 0-1.4 ohms. Then, they often gain resistance or open when power is applied to them for the first time in over 10 years. You're thinking, "oh, I tested the jumper(s), its not that..." and you go through everything until you finaly realize the jumper(s) is (are) the problem. Some of the zero ohm jumpers may have been replaced with wire at the factory, or you may have to replace all of them. 2. Add the diode mods You'll need the following diodes to do this: (4) 1N5342B 7.5v 5 watt Zener diodes (I get these from Mouser, http://www.mouser.com, part #625-1N5342B, 7 cents each) (4) 1N4002 diodes (Mouser part # 583-1N4002, 3 cents each) About 15 inches of 5mm heat shrink tubing, 4mm will also work The first thing you have to do is connect the Zener (1N5342B's) diodes anode-to-anode in pairs. (The line side of each diode will face away from each other). Take 2 Zener diodes, and twist the leads of the anode side of each diode together. Leave about 1 inch of lead distance between each anode, and solder the pair together. Repeat this procedure for the other 2 Zeners. You should now have 2 sets of 2 Zener diodes, connected anode to anode with about 1" of lead space in the middle. Leave the end leads long, we can allways trim these later. Next, you will want to desolder the orange (x input) and yellow (y input) wires from the deflection board. Clear the solder holes for each with a soldapult or your desolder station. This is a good time to check the orange and yellow wires for crimping; they may have become strained from the weight of the harness. If needed, cut and restrip them. Solder one cathode side of a diode pair to the parts side of R6 (1.5 ohm, 10w) closest to Q22. This is the end of R6 that faces away from the heatsink. Solder a cathode side of the OTHER diode pair to the parts side of R29 (1.5 ohm, 10w) that faces away from the heatsink. You should see a black wire on the board that links R6 to R29. You are attatching each diode pair to the same end as this black wire. Check for cold joints on the solder side of R6 and R29 after you have soldered each diode pair to the parts side. Now, use your heat shrink tubing to insulate each diode pair - slide enough on to leave about 3/4 inch at the unsoldered end of each diode pair. Take the end of the diode pair attatched to R6 and feed it through the yellow hole (y input), and take the end of the diode pair attatched to R29 and feed it through the orange hole (x input). leave enough exposed lead on the parts side to resolder the yellow and orange wires to their respective diode pairs. Solder in each diode pair, then solder on the orange and yellow wire to each. I'm going to try to take a couple pictures to clarify this, hopefully they'll be on this guide soon. Next, we are going to put the 1N4002's on the solder side of the board. If you look at the solder side of the board you will notice there are 2 rivets that attatch the heatsink to the board. Rotate the board so that the heatsink is closest to you, solder side up. You want to scrape a 1/2" area of the insulation from the ground area about 1/2" NE of the left rivet, and 1/2" NW of the right rivet. Locate the two nuts and bolts that are closest to the center of the heatsink. Scrape (2) 1/2" squares again, about 3/4" to the right of the left bolt, and about 3/4" to the left of the right bolt. Find the emitter trace for each of the 3792 transistors (Q7, Q17). This trace is connected to the collector of each 3716 transistor (Q6, Q16). This trace for Q16 and Q17 runs from the collector of Q16 through the emitter of Q17, to the fuse socket F2. This trace for Q6 and Q7 runs from the collector of Q6 through the emitter of Q7, to the fuse socket F1. You'll want to scrape about 1" of the insulation off of this trace between Q16 and Q17, as well as 1" off of the trace between Q6 and Q7. Now, we are ready to attatch our 1N4002 diodes. Solder the cathode (line side) of the 4002 diode to the trace that goes to the emitter of Q17. DO NOT solder the diode directly to the emitter of the transistor, but to the trace about 1/2" away from the emitter. This will just make things difficult should you ever have to replace the transistor Now, insulate the diode with your heatshrink tubing, leaving enough open area so you can solder the anode end to the collector (this is the 1/2" square we scraped the insulation from closest to the right-center bolt.). Now you can solder the anode end to the collector of Q17. You want to use this same technique to solder the remaining 1N4002's, following the designations below: For 3792's (Q7, Q17) 1N4002 cathode at emitter, anode at collector of each transistor. For 3716's (Q6, Q16) 1N4002 cathode at collector, anode at emitter of each transistor. I hope to have a picture illustrating this soon. Hopefully everyone can understand the above text description for now. 3. Reccap Here is my replacement cap list. All caps should be 105 degree low ESR's. As in the HV guide, many might consider these replacements OVERKILL, but I haven't had to replace caps for a second time yet... C7, C8, C9, C10 1uf @ 100v (axial) C17, C18 4700uf @ 100v (radial) C19, C20 100uf @ 50v (radial) C24 33uf @ 250V (radial) Be sure to install all caps with correct polarity. 4. Replace X and Y size pots I usually install these on early boards that don't have them. If they are on the board, I replace them. Original ones can often cause jitters in the monitor. Tuner cleaner is only a temporary fix. Simply replace these 10k pots, they cost less than $1 each. 5. Resolder & Repair Harness Wires Check all harness wires where they connect to the board. These wires often become crimped. You will often find some attatched by one strand. Cut and restrip the wires as needed, and resolder all the harness joints whether they need it or not. After you're done, check the continuity of each wire with your meter from the board to each male harness plug in the molex connector. Clean the connector if needed. 6. Check for Shorts, Opens I use diode test on my meter to check each diode in curcuit for a good one-way junction drop of .4v to .8v. If I see any readings that look unusual, I'll pull one lead and acurately check the diode. I've seen a few CR3, CR4, CR12, and CR13 (all 1N914's) go bad, you may just want to pull a lead to test these diodes. Don't hesitate to replace any questionable diode. If one fails, it can and usually will take other components with it. I also use diode test on all transistors, pulling an testing any that show unusual readings. It can be common to find a 3906 or a 3904 that has been pushed over on the board, causing its leads to short. Make sure the transistor leads are situated properly and not shorting themselves or a nearby component. This can also happen with the leads for Q4 & Q14 (MPSU57) and Q5 & Q15 (MPSU07). Amplifone delfection boards have the RGB color transistors (Q23-25, D40P5, NTE228A) mounted near the bias and drive pots. The base of these transistors can short to nearby components if they are bent away from their plastic "snaps" and lean twoard the groups of resistors above them. I test all resistors in curcuit first. If I see any unusal readings (15% out of spec) I pull a lead to test the resistor out of curcuit. You may want to double check R14 (1.2k, 1/2 watt) R72 (1.6K, 1/2 watt). If these need replaced, I usually upgrade them to 1 watt. 7. Replace all Deflection Transistors, Test MPSU07's, MPSU57's When looking at a board for the first time, I allways test the fuses F1 and F2. You can bet if one is blown, you probably have a bad 3716 or 3792 (or both) on that side. Before removing old deflection transistors, I test them on diode test in curcuit. If you find a short in a deflection transistor you will want to pull and test the MPSU57 and MPSU07 next to it as well. Allways test your old 3716's and 3792's before you install new ones. This can lead you to find a problem before the new transistor is installed so you don't risk damaging a new one. I allways replace all deflection transistors when rebuilding a board. I also replace the mica insulators. Remeber to apply an even coat of heat sink compound, and allways check on continuity for shorting to the heatsink by either the base, collector, or emitter. 8. Find and resolder cold joints The most common places I find cold joints are at the harness wires, the thermistor (R74), the fuse sockets (F1-F4), J103 (HV jack), and J105 (yoke jack). R6 and R29 (1.5ohm 10 watt power resistors) can also get cold joints, as well as J104 (jack for degaussing coil). 9. Clean jacks and connectors to main harness and J103, replace bad pins These connectors can often get pitted. I've seen some so bad that they'll break when you put any pressure on them. I check these for contiuity. If they are showing some resistance (over 3 ohms), I replace the pins. These are standard .093" molex pins. I get them from Hosfelt Electronics (800-524-6464)