Alright, finally forced myself to sit at my PC and start organizing all of my notes and pics that I've been collecting over the past several months of various repairs that I've done on various games. This is the first time I've ever really "blogged" anything, so forgive me if things are not clear or in order or if there are things that I have missed. I already KNOW I'm missing a number of pics which I'm kinda bumed about, but I digress... This will be a work in progress section, and I'm sure the more entries I do the better I'll get at it, and I'll have a better understanding of what pics I should be taking along the way. When I'm working on stuff the last thing I'm thinking about is what pics I should be taking for my post as I'm wrapping my head around the repair.
Anyways, with that I've decided the first entry will be a straight forward repair that Warlock brought to me. A friend of his owns an Austin Powers that had the trough up kicker coil stop working. Scott and Walt went to diagnose, and after consulting with me about the issue they determined the coil itself was shorted and the subsequent driver board MosFET was also borked. Changing the coil out was something they could handle on their own, but asked for my assistance with the PCB repair.
When I received the PCB I noticed that the part in question had already been removed for me, which was a nice gesture. (notice there are 2 parts missing, the one on the left is the FET for the coil and the one on the right is a transistor for an optional coin counter that is not used in the game - I had to confirm with the manual in case this needed to be addressed)
Now when you hear people talk about board work, and how it takes a decent amount of practice before you get the hang of it (or that PCB rework is just not for everyone), this is what we're talking about... In this photo (and the one above if you had sharp eyes) you'll notice that a couple of the solder pads and associated traces have been lifted / ruined. This can happen for all kinds of different reasons, from too much heat from your iron to too little heat from your iron and pulling the part out before it's ready and so on. Unfortunately there isn't really a set amount of heat or time you should apply to a PCB when removing a part as every part and PCB is different, so it all comes down to "feel". (sorry, that's the best way I can describe it)
You'll notice that the top and bottom pads are completely gone. The middle pad and trace have been lifted from the PCB surface. The other thing to note is the lower pad that is missing, also had 2 traces attached to it and you can just barely see whats left of one to the lower left of the hole. (the little copper strand) All of these traces will now need to be fixed with jumpers. Luckily the majority of pinball PCB's are single or dual layer (traces on the bottom, or top and bottom) which makes repairing broken traces fairly easy. In this case I can see exactly where the traces route to and will not require the schematics.
In this pic you can see I have installed the new MosFET and tacked it in place using what's left of the original middle pad and lifted trace. I have bent the bottom leg of the FET over and soldered it to the pad where one of the lifted traces originally ran as this will help keep the FET physically in place while also acting as a jumper. In the following pic I have added a jumper wire to the bottom leg of the FET to recreate the second trace that was originally attached to this pad, and I also doubled up the middle lifted trace as a safety measure. Where that pad and trace were damaged already it's just good practice as you never know how long it will hold up in the game with heat and vibration.
In this last pic I'm showing how I handled the top leg pad that got ruined. This leg of the FET is tied to the ground plane in the PCB, and even thought the bottom side of the pad was ruined, the top pad was still in tact, and still usable. In these instances you must solder the part from the top side of the PCB as the solder will not re-flow from the bottom through to the top as it normally should when the pad (and via) are in tact.
And with that, this driver PCB repair is complete and ready to be re-installed in the game.
(forgot to mention it's always good practice to ring out any and all repairs with your DMM to confirm there are no shorts and that your jumpers are good)
D.
Anyways, with that I've decided the first entry will be a straight forward repair that Warlock brought to me. A friend of his owns an Austin Powers that had the trough up kicker coil stop working. Scott and Walt went to diagnose, and after consulting with me about the issue they determined the coil itself was shorted and the subsequent driver board MosFET was also borked. Changing the coil out was something they could handle on their own, but asked for my assistance with the PCB repair.
When I received the PCB I noticed that the part in question had already been removed for me, which was a nice gesture. (notice there are 2 parts missing, the one on the left is the FET for the coil and the one on the right is a transistor for an optional coin counter that is not used in the game - I had to confirm with the manual in case this needed to be addressed)
Now when you hear people talk about board work, and how it takes a decent amount of practice before you get the hang of it (or that PCB rework is just not for everyone), this is what we're talking about... In this photo (and the one above if you had sharp eyes) you'll notice that a couple of the solder pads and associated traces have been lifted / ruined. This can happen for all kinds of different reasons, from too much heat from your iron to too little heat from your iron and pulling the part out before it's ready and so on. Unfortunately there isn't really a set amount of heat or time you should apply to a PCB when removing a part as every part and PCB is different, so it all comes down to "feel". (sorry, that's the best way I can describe it)
You'll notice that the top and bottom pads are completely gone. The middle pad and trace have been lifted from the PCB surface. The other thing to note is the lower pad that is missing, also had 2 traces attached to it and you can just barely see whats left of one to the lower left of the hole. (the little copper strand) All of these traces will now need to be fixed with jumpers. Luckily the majority of pinball PCB's are single or dual layer (traces on the bottom, or top and bottom) which makes repairing broken traces fairly easy. In this case I can see exactly where the traces route to and will not require the schematics.
In this pic you can see I have installed the new MosFET and tacked it in place using what's left of the original middle pad and lifted trace. I have bent the bottom leg of the FET over and soldered it to the pad where one of the lifted traces originally ran as this will help keep the FET physically in place while also acting as a jumper. In the following pic I have added a jumper wire to the bottom leg of the FET to recreate the second trace that was originally attached to this pad, and I also doubled up the middle lifted trace as a safety measure. Where that pad and trace were damaged already it's just good practice as you never know how long it will hold up in the game with heat and vibration.
In this last pic I'm showing how I handled the top leg pad that got ruined. This leg of the FET is tied to the ground plane in the PCB, and even thought the bottom side of the pad was ruined, the top pad was still in tact, and still usable. In these instances you must solder the part from the top side of the PCB as the solder will not re-flow from the bottom through to the top as it normally should when the pad (and via) are in tact.
And with that, this driver PCB repair is complete and ready to be re-installed in the game.
(forgot to mention it's always good practice to ring out any and all repairs with your DMM to confirm there are no shorts and that your jumpers are good)
D.
Last edited:
