Fun With Heat Gun

Unsolder Components
There's more to use it for than heat shrink. Unsoldering components with a desoldering iron and solder sucker can take awhile. With a heatgun solder melts all at once which lets things just pop out. It takes less effort and sometimes will work better. Although it is much easier, I think it has more risk. After awhile things can start smoking and be too hot to handle for a minute. The fumes of melting plastic are toxic, and the heat can damage the components being retrieved.



Why?
I bought a nice AXP motherboard a few months ago for $5 and it turned out it didn't work. The northbridge has a physically minor yet fatal chip in it. It was unfortunate, but for me it still has its money's worth with the components. The capacitors on it are commonly used on boards and would let me repair something. Also when bread boarding things it's nice to have more choices; like with Lego pieces. By clearing the board the components can be stored easier. A lot of these chips I can't really use or damaged them from removal, but it's cool to see them fall off and then examine them.

First Round



Row 1: toroidal inductors, crystal oscillators, diode, CR2032 socket, jumpers
Row 2: NF2 southbridge, NF2 northbridge, SATA controller, thermal controller, bios
Row 3: RCA jack, serial header, capacitors, green LED
Row 4: PCB mount L-SATA connectors
Row 5: 3-pin fan headers, jumper header

Second Round



Row 1: DIMM anchors, jumpers
Row 2: Socket 462 housing
Row 3: Ethernet & USB module, ATX 20-pin male
Row 4: Various Chips, Capacitors
Row 5: Header, Voltage regulator?, Inductors, Oscillator

Thoughts
I was amused to get that socket out minus a few pins. It was pretty simple, heat up the back side and keep tapping it without getting burns. I should collect sockets along with the processors I've hoarded. As for the use of these parts, to be realistic, the caps and fan headers will probably be the only things I reuse. I might use the RCA jack for another project. From the first round the Silicon Image chip looked familiar to me. It turns out it's in a card I have on my desk.



Now I wonder what would happen if I took a board that shares a PCB layout with a deluxe model and obtained chips for the empty pads. Could the board be self-upgraded? Add 1394 or a comm port to something. There's not much going on here, but I felt like making this my first thread on [H]. I like taking photos and doing stuff with electronics, so if there's a mild interest I'll post future things. I've got two Lian Li desktop projects going on that I'll definitely post somewhere once I'm finished. Custom cabling works the best for wire management.

Companies often make one PCB layout for a range of models, leaving out options but with the silk screening and holes/vias intact. It could be worth a try, but I wouldn't do it if I didn't have a clue as to how the circuit was supposed to look like. Especially on multi-layer boards it's hard to see how a circuit is put together, so you could forget a crucial part or get the numbers wrong on one you add (hard to guess/calculate resistor values and overkill can be harmful).

Don't do it on a board you want to keep using

Nice way to get your paws on cheap parts, BTW. I keep random PCBs lying around for parts as well. Never tried using a heat gun for desoldering yet, though

I'm assuming this is only good for completely desoldering a board, not just removing one component and replacing it? Seems like it'd melt away a large area of solder at once... very nice idea.

plot said:

I'm assuming this is only good for completely desoldering a board, not just removing one component and replacing it? Seems like it'd melt away a large area of solder at once... very nice idea.

Click to expand...

There's a large blast of hot air coming out of it, so yes, it'd be best suitable for larger areas (few square cm at least). Not something I'd use for small SMD components, though for large SMD chips it's kind of like a reflow station in miniature

Nice work! I tend to take apart busted power supplies--there are TONS of cool parts inside those, from high-voltage transistors to high-current schottkey rectifiers to big caps to high-current transistors to optocouplers to heatsinks.

I never knew you could use a heat gun to desolder components. Thanks for the tip!

Playstation 3 Repair
Heatgun wins again! It repaired a broken PS3 my friend got from ebay for $100. The gun was used to reflow the BGAs on two of the ICs.



Issues
1) Power on would fail with three beeps and a blinking yellow light.
2) Bluray drive had a disc jammed in it.
3) One of the USB ports had the plastic piece broken off.
4) No hard drive or caddy.

Disc Jam
We disassembled the entire system and easily got the disc out by removing the top of the drive. The drive still seems to have mechanical issues that need attention.


Sony's slot loading Bluray drive is like a mad scientist's chaotic clockworks. Anyone a watch repairer?

USB Port
I pointed out, "Hey this motherboard on your shelf with a thick layer of dust on its PCI and ISA slots has some USB ports. Let's scrap it." He then proceeded to jam a screw driver in snap out the USB plastic. With some glue and a device to hold it in place it worked perfectly.


Crusty Paste & Broken USB

Hard Drive
This guy let us use any drive, but we used my spare Eee 2.5" 160GB drive. The original owner probably thought the caddy was part of the drive. I easily convinced my friend to leave it and not to pay $30 on ebay for a piece of metal. So without the caddy he might as well eventually get a 1TB in there. Although there are ebay auctions selling 2.5" drives with PS3 caddies.




Power Failure
The feedback the console gave us seemed to mean heat. This part took many hours to figure out. We ended up powering the 12V 2.65A 140mm slot blower fan with a computer PSU to blast it. After that I shouted over the fan that it's not a heat issue. The internet confirmed my belief that the initial cooking broke the solder joints on the chips. After two reflow attempts the unit finally stayed on and let us do things.


Nidec Slot Blower. Custom made for Sony, then hidden away from public catalogs.


Sony's Dramatic Chip Names. It will synthesize reality. Same one used in the Matrix.


Conclusion
$100 + shipping got the best version (60GB 1st gen) of the Playstation 3 console because we took the effort to repair it rather than let someone stick it in a landfill. The bluray drive still needs work, but I'm sure there are ways already to play games without it.



The top of the motherboard. Yes, everything inside is upsidedown.


Wireless Module. More damn ribbon cables.


The tool on the right told us the current draw. (119V 1.3A)

Nice job

I'm still disappointed at Sony for removing PS2 BC on later models I honestly can't play the PS2 on a 46" HDTV as it's just hideous. Have to use a PS2 emulator now

this is fine if you salvaging resistors, inductors, dry capacitors, and connectors... but i really don't see this being a good aproach for the removal of transistors, wet can capacitors, ic modules, leds, diodes..... or really any other part that can be damaged by high heat.... not to mention the noxious fumes from the melting plastic some of which are carcinogens.....

I used the "low" heat setting and recently got a bunch of IC's off an old board for lab parts in class. 7400 series gates were needed, and they turned out to still work after the heat. I didn't have my camera with me, but I still have everything. Though it would mostly be photos of more of the same. After practicing this enough I don't really get to the point where the plastic melts. Or I've been lucky enough to have boards that don't need much heat.

some of the older boards i have come across almost needed a propane torch to melt the solder.... *cringes* otherwise yha.... with practice it can be done....