Cap Replacement - Page 1
Forum section: electronics / general

author: Legion
author_rank: Frequent Contributor
timestamp: March 24, 2014, 04:03:47 am
content: Just spent the last few hours replacing caps in a game gear for a friend. Screen is all messed up. Didn't fix anything, but it didn't make it worse either. In an entropic universe, I consider that a victory. Think this calls for a beer, shot and a smoke.

author: Legion
author_rank: Frequent Contributor
timestamp: March 24, 2014, 04:05:02 am
content: Only burned/blistered myself 4 times too. Yeah, I was hot tonight*.*No pun intended.

author: XOIIO
author_rank: Super Contributor
timestamp: March 24, 2014, 04:14:49 am
content: It took a few hours? I'm guessing you are fairly new to this sort of thing.

author: Legion
author_rank: Frequent Contributor
timestamp: March 24, 2014, 04:22:38 am
content: Quote from: XOIIO on March 24, 2014, 04:14:49 amYes. I'm new to soldering. Desoldering some of the old caps took a little longer than expected.

author: XOIIO
author_rank: Super Contributor
timestamp: March 24, 2014, 05:06:45 am
content: Quote from: Legion on March 24, 2014, 04:22:38 amAh yes, that can be a pain, get a desoldering pump if you can, they are pretty cheap, and worth every penny.

author: TMM
author_rank: Frequent Contributor
timestamp: March 24, 2014, 06:05:17 am
content: The manual solder suckers/pumps are pretty useless for cap replacement imo. Combination of tight hole-to-lead tolerances and being attached to a large ground/power plane defeats wimpy soldering irons and manual pumps.I've had far better success by adding extra leaded solder to the pads, then heating up each pad alternately and rocking the capacitor side to side, pulling each lead through about 1mm at a time until it's out.

author: pickle9000
author_rank: Super Contributor
timestamp: March 24, 2014, 06:37:50 am
content: If your going to get a solder sucker go for a big one like the classic Soldapullit deluxe cost about 25 bucks. Or for the ebayer a cheap knockoff like this.http://www.ebay.ca/itm/New-Solder-Sucker-Desoldering-Pump-Removal-Tool-/320951879167?pt=LH_DefaultDomain_0&hash=item4aba3905ffThe style is very common and once you know how to use it effective.As for big ground planes and underpowered/ low mass irons cut then there are many other techniques and tools. Cut them off remove pin at a time, professional grade sucker irons, stainless needle tubes, basically anything you can imagine.

author: Richard Head
author_rank: Frequent Contributor
timestamp: March 24, 2014, 10:04:23 am
content: To avoid pulling out the THP heat up both leads simultaneously and remove cap briskly.Sometimes I use two soldering irons with a helper.

author: Legion
author_rank: Frequent Contributor
timestamp: March 24, 2014, 12:23:45 pm
content: Quote from: pickle9000 on March 24, 2014, 06:37:50 amI own the one in the ebay listing. Got it from ActiveTech a while ago. First time using it. It was good for removing solder that had blocked the lead holes through the board for through hole components. They didn't have a picture of it on their site when I bought it. So when it came I was a little surprised. Figured something giant and plastic would just melt. But it held up well.

author: Legion
author_rank: Frequent Contributor
timestamp: March 24, 2014, 12:24:49 pm
content: Quote from: Richard Head on March 24, 2014, 10:04:23 amExactly. I found if I could heat up both pads at once the cap would come off real easy.

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: March 24, 2014, 12:41:06 pm
content: Sometimes I use a 100/140 watt soldering gun with a piece of 12 or 14 AWG copper (solid) wire wrapped around the end of the tip, with the other end free (if you attach the wire to the tip in two places it shorts out the heating current to the tip).I bend the free end of the wire at 90 degrees and use that as a heating extension to the tip to lay across both capacitor terminals at once. Optionally, if that extension wire is clean and fluxed, it will also wick solder away from the component terminals.

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: March 26, 2014, 11:03:57 pm
content: Doing a cap replacement on a Game Gear is horrid. I have six of them at home waiting for me to sell them.The first problem is getting the old ones out. They're can caps, but the can is encased in a plastic cover, and the cap is folded over the solder points. Removing the caps makes your house stink like burning fish... and hopefully you don't lose the pads to either removing the cap, or bad electrolyte eating the pad away.Then the next part involves putting in new caps. If you use regular can caps, you have to make sure they're not too wide or else you can't get the unit back together when you're done.That doesn't even include the caps on the sound board or the power board. Those are even worse to get at. Don't get me started on that sound board.Having said all that, how busted is the screen? Is it just dark? Maybe the backlight bulb is on it's way out. You might be interested in removing the backlight and replacing it with a couple white LEDs and a drinking straw.Here is the schematic for the backlight section.Easiest way I can think of is to remove everything in the top right corner. Positive lead goes on the positive side of L2 (or R55/R57), and the negative lead goes on the negative side of C68. Use an appropriate resistor for the LEDs, and the contrast dial should still work afterwards.

author: Legion
author_rank: Frequent Contributor
timestamp: March 27, 2014, 02:55:21 am
content: Pretty sure it's irreparable. The screen lights up, but you just get a fixed image of random pixels. Replaced all the caps on the main board and the power supply. Didn't make a difference. You're right about the fish smell.