Lifted pads are not uncommon, particularly in DIY work where you don't have the right equipment to control temps. You can still use the board in many cases if you carefully scrape the trace remaining to the copper, tin it, then take a strand of wire, smaller than the width of the trace and lay it along the tinned area and solder it down, leaving enough to reach the pin. Cut the remaining length to just long enough to lay over the part of the pin that solders to the land, then touch your iron to the pin to heat it enough to solder the wire. Flux helps, and if the wire is aligned carefully, the solder and gravity will keep the wire in place while the solder melts enough to make the connection.
50" Hitachi plasma
Going to attempt to replace buffer chip on sdr board, buying a weller wes51 station, is this a good one for this type of repair?
21 - 28 of 28 Posts
Thanks, where is a good place to get these small copper stencils...or the small wire? This will save me from trashing the board cause I only have 2 places to fix...
lcaillo, Thanks for your reply. Yes, I've done that before but never on something this small. Luckily, the pads that lifted are tied to the pins next to them so I'll just bridge over to the next pin. I was really kind of surprised to see the pads missing. Once I cut the legs off of the chip, I really didn't put a lot of heat down to remove the pins from the pads. Next time I'll be a little more careful.
You seem to have the technique down for removing these buffer chips. What soldering iron are you using? I have a Weller TC202, 60W iron, fixed temp. with various size tips. I used my largest tip which is wedge shaped approx. 1/4" in diameter. I couldn't for the life of me get enough heat through the chip to unsolder the plate on the backside of the chip. I almost pulled out my monster 100W iron with a 1/2" tip but I restrained myself.
I think next time I'll drill a hole through the center of the chip until I reach the plate. I'll them put the soldering iron directly to the plate.
You seem to have the technique down for removing these buffer chips. What soldering iron are you using? I have a Weller TC202, 60W iron, fixed temp. with various size tips. I used my largest tip which is wedge shaped approx. 1/4" in diameter. I couldn't for the life of me get enough heat through the chip to unsolder the plate on the backside of the chip. I almost pulled out my monster 100W iron with a 1/2" tip but I restrained myself.
I think next time I'll drill a hole through the center of the chip until I reach the plate. I'll them put the soldering iron directly to the plate.
Hey George, thats sort of the same thing I had to do to get it off, just broke the chip...I would guess it would take hot air or some kind of preheater to properly remove these chips. Jason1976 posted some good info about repairing these boards, I thinks after the holidays I might get some time to sit down and try these repairs, the kids are taking up my time right now, haha, I have to get some wire or copper stenils, I watched a video on you tube on a guy soldering down some new copper traces. Looks like maybe with the time and a good magnifier AND a whole lot of patience this can be done sucessfully. I love doing this stuff, wish I would have went into the electrical engineering field like my brother, just a hobby for me though, but very interesting. Its funny the things you can actually repair with the right info like from this site!
I use strands from speaker wire scraps.Thanks, where is a good place to get these small copper stencils...or the small wire? This will save me from trashing the board cause I only have 2 places to fix...
Actually, I have never changed buffers on these models. I have on others and they were not soldered in the middle. When I run into a chip that I think is soldered in I either use hot air or place a ball of solder on top of the chip after cutting the pins off. I have heard of using thin strips of copper slid under the chip to get the heat to the plate, but never have tried that method.lcaillo, Thanks for your reply. Yes, I've done that before but never on something this small. Luckily, the pads that lifted are tied to the pins next to them so I'll just bridge over to the next pin. I was really kind of surprised to see the pads missing. Once I cut the legs off of the chip, I really didn't put a lot of heat down to remove the pins from the pads. Next time I'll be a little more careful.
You seem to have the technique down for removing these buffer chips. What soldering iron are you using? I have a Weller TC202, 60W iron, fixed temp. with various size tips. I used my largest tip which is wedge shaped approx. 1/4" in diameter. I couldn't for the life of me get enough heat through the chip to unsolder the plate on the backside of the chip. I almost pulled out my monster 100W iron with a 1/2" tip but I restrained myself.
I think next time I'll drill a hole through the center of the chip until I reach the plate. I'll them put the soldering iron directly to the plate.
I sort of figured this was something different because of the middle being soldered down, usually everything shows just the pins being soldered. Well anyways I got my new sdr boards, upper and lower, one I found on ebay for 40 and the other for 68 on ebay. The $40 one was out of a used set and not repaired, I think I lucked out on the price. The $68 one had a repaired buffer chip, the clear silicone used on it was a little sloppy but the board works fine. I did have a of a time getting the lines out until I tried to push one ribbon in a little harder and felt it bottom out, I turned it on and that section worked fine, so I just pushed in the remaining ribbons a little harder and they all seated and the picture is perfect!.. So A little $$ and two sdr boards and 2 caps later and its up and running, thank you all for the help and info, this site is priceless!
I have replaced a few of these IC chips. First time was using a hot air, heat station. This was done at a friends place of business which happened to be very circuit board related.
The easiest home remedy way to do this is to use a heat gun with a reducer tip that concentrates the air flow. Set the fan speed at the lowest output and the heat at 1/2 to 3/4 the max temp. After scraping off the sylicone with a hard piece of plastic (or your finger nail), clean up between the fingers with a needle and then clean the rest off as best as possible with a toothbrush and rubbing alcohol.
Place your heat gun directly over the IC, but not placing it directly on top and use the needle (or something similar but longer so you don't burn your finger tips) to gently pry up a corner of the IC. MAKE SURE the solder is all hot and melted or you could pull up the fingers under the IC that are part of the board itself!! (I've done this practicing).
There is solder behind the chip, it's not glue or a binding agent, it's solder. That is why it takes a while to be able to lift the IC off, the solder under has to melt.
When placing a new IC on the board, just place flux on the back of the IC chip and on the fingers of the chip. Put it into position using some sort of magnifying device....I use a jewelers loop. Line it up and put heat to it. Once there is enough heat the IC will float and you can make your corrections to line it up from there. Once you have it perfectly in position, put a little pressure on it with your needle or whatever you use to squish it down. Take the heat away and let it set for a second or two. Look through your loop to see if any of the fingers are above the solder if this happens take your soldering iron (hot) and place it on the finger to solder it down.
Hopefully this helps
The easiest home remedy way to do this is to use a heat gun with a reducer tip that concentrates the air flow. Set the fan speed at the lowest output and the heat at 1/2 to 3/4 the max temp. After scraping off the sylicone with a hard piece of plastic (or your finger nail), clean up between the fingers with a needle and then clean the rest off as best as possible with a toothbrush and rubbing alcohol.
Place your heat gun directly over the IC, but not placing it directly on top and use the needle (or something similar but longer so you don't burn your finger tips) to gently pry up a corner of the IC. MAKE SURE the solder is all hot and melted or you could pull up the fingers under the IC that are part of the board itself!! (I've done this practicing).
There is solder behind the chip, it's not glue or a binding agent, it's solder. That is why it takes a while to be able to lift the IC off, the solder under has to melt.
When placing a new IC on the board, just place flux on the back of the IC chip and on the fingers of the chip. Put it into position using some sort of magnifying device....I use a jewelers loop. Line it up and put heat to it. Once there is enough heat the IC will float and you can make your corrections to line it up from there. Once you have it perfectly in position, put a little pressure on it with your needle or whatever you use to squish it down. Take the heat away and let it set for a second or two. Look through your loop to see if any of the fingers are above the solder if this happens take your soldering iron (hot) and place it on the finger to solder it down.
Hopefully this helps
21 - 28 of 28 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Home Theater Forum and Systems
A forum community dedicated to home theater owners and enthusiasts. Come join the discussion about home audio/video, home theaters, troubleshooting, projects, DIY’s, product reviews and more!
Full Forum Listing
Top Contributors this Month
View All
RobKnapp
9 Replies
briannarichardson2
8 Replies
Da Wiz
7 Replies
Recommended Communities
