This is an informational guide for instructions on how to repair a damaged circuit board, damage resulting from the upper grip panel screws scratching the board and damaging one or more of the circuits. If you haven't already read the information page about this problem, please do so now (much information is contained there, regardless of whether or not you already damaged your board). The page can be found here.
Be warned. This repair is extremely intricate and requires no less than someone with both soldering expertise and experience. The repair, if done incorrectly, can result in further damage to your circuit board. If you have a Parker solenoid, you will have to desolder you board; this is an extremely fragile operation and you may damage your solenoid (which requires a $125 replacement). Lastly, you may seriously burn yourself in the process. I of course am not responsible for any damages to yourself or your equipment. You've been warned!
Read through this entire guide BEFORE performing the activity.
Removal of the Board:
As stated, if using a Parker solenoid, the board will need to first be removed from the solenoid so that you can have access to the underside (the damaged portion). Although the board need only be desoldered from the solenoid's two terminals (located directly behind the LED), this is the most difficult part of the repair in my opinion simply because the solder terminals on the solenoid are extremely fragile. You must be careful not to pull the board off the terminals if they are still attached to the board's via pinholes. If you pull the terminals up, the solenoid will be useless (and require a $125 replacement).
Furthermore, the board is stuck to the bottom of the coil by the small "spacer" (the white pad seen between the coil and board). This makes it difficult to tell whether the terminals are free from the solder pinholes (called "vias") and the board is being held down by the spacer, or if the terminals are in fact still connected. If the terminals aren't connected you can just pull it off, otherwise not. To be able to tell the difference simply comes with experience; there's no way I can explain it.
If you have a Humphrey solenoid, simply remove the spacer screws and slide the board off the back of the coil. (See why I like them more?)
Circuit Repair:
Once the board is off, you can get down to the repair. What you will first need to do is find the side that is damaged. In this picture of a board I happen to be using for pictures, the right side of the board is damaged, and two circuits are clearly severed.
As stated in the information page, only a severed circuit needs to be repaired. It's possible for the screw to damage the board, even impact on the circuit etching, while it will still function.
I should mention right now that, although I am about to perform a repair on two separate circuits for this board, doing so is significantly more difficult than the repair for only one circuit. Repairing two circuits on the same side of the board requires you to use even more precision than before, and also first plan out the angles of approach for your jumpers. I don't describe these activities because they were only learned by experience after repairing dozens of boards myself. Again, you've been warned.
Anyways, once you find the circuit(s) that require repair, you will need to use a knife, file tip, or some other tool to scrape away the green soldermask covering the etching. The soldermask is a protective layer that prevents shorting of the circuits when they come in contact with something (it's also what makes the board green). Underneath the soldermask, the copper circuit etching is shiny yellow/gold colored. You will need to figure out where you will be soldering, then shave off the soldermask in that location.
Which brings me to my next point, what you will use to bridge the damage on the board. For the repair I usually use the solder leads from spare LEDs I have available to me. You can realistically use anything that conducts and can be soldered, such as a small length of wire.
if using metal leads like myself, you will want to scrape the soldermask off directly around the board damage. If using a wire then it's less important where you solder at, just as long as it's on the same circuit (obviously). In the below picture, I shaved away the soldermask on each side of the two damaged circuits, preparing the attach the jumper.
Installing the tiny jumpers can be difficult. You might be able to use a small clamping mechanism like alligator clips or a surgical clamp, but you'll need to be careful not to damage anything on the other side of the circuit board. You might also be able to hold the jumper in position with one hand and apply the solder with the other, if you're tricky. The following two pictures show the board after jumping the first damaged circuit, then the second damaged circuit...
The board is now repaired and working. Here's a picture of a different repair, this time using a wire jumper instead. Using a small piece of wire will work equally good, but you must be careful since the wire is much more thick. The upper board must sit flush on top of the solenoid so anything trapped in between the coil and board will prevent it from lying straight.
Checking the Repair:
Once the repair is in place you'll have to reattach the board to the solenoid. If, after being resoldered onto the Parker solenoid, your board doesn't function, it might mean your solenoid terminals were damaged in the removal. If this is the case then you will need a new solenoid for $125.
A completely functioning board will have a working powerswitch, LED, and a solenoid that clicks. These are the only circuits that can be damaged on the board (in this case). In the above pictures, the damaged circuits control the positive voltage for the solenoid and LED, and the smaller one was for the powerswitch. There are different board versions available, though, so your board may appear different.
Related Links:
· Electronics Troubleshooting
· Grip screw damage information page.