Popular Post Lord Gruntfuttock Posted February 17, 2018 Popular Post Posted February 17, 2018 Had another crack at fixing broken electronics... About a year ago our LG LCD telly gave up the ghost at around 4 yrs old, just out of warranty, natcherly. Just sighed and bought a bigger one at the time, and put the koozed one away behind the couch. Now we've renovated I decided to have a look at it. From memory the thing powered up but there was no screen action, so was probably something a bit technical (ie not a fuse or similar). Not much in these things, a power board and a main board, with connectors to all the gubbins (didn't take pics as I was pretty sure I'd end up taking it to the tip, so these are interweb screen grabs). Power board on left, main board on right... Not my board but very similar, shows the 3 plug and two ribbon connections you have to disconnect to get it out... I looked for anything obvious, and also for spare boards online but think the 47" was a bit of an orphan, so there's not much about that doesn't cost more than a new telly. I was pretty sure it was the motherboard that had a problem with a bad solder connection, so decided to bake it, as I really had nothing to lose. Solder melts around 185 - 215 Celcius (depending on composition) so I ramped the oven up to around 200 then placed the board on a cardboard stand (don't use metal)... A couple of minutes into it I checked temps, was pretty much spot on, around 204 deg max. Left it in the oven for 10 minutes, then turned off and opened door so it could cool. Really important not to move it until everything has set in place... Once it was below 120 degs I removed it and let it cool completely before reassembly. On first power up it did more than it had previously, but the screen was garbled pixels, so I had another go at connecting the two ribbon cables (used a magnifying stand to make sure they were lined up better this time). And voila (bottom telly)... Pretty bloody surprised actually. It's a smelly process too by the way, so best to run extractor fan/open windows. To give it a proper test I bung it on the bedroom wall mount and looked on my hard drive for a high def movie to watch. Went sweet... Will place in the family room as watching pron on this size screen at the end of the bed is a bit daunting... 21 9 Quote
tortron Posted February 17, 2018 Posted February 17, 2018 I did the same to an LG with pink screen of death. Got another couple of months out of it, but has done it again. Might try cook it again before I dump it 2 Quote
NickJ Posted February 19, 2018 Posted February 19, 2018 Used to have to do that monthly to the logic board in my Macbook, worked flawlessly until I put it in a glass roasting dish with a convex base, just twisting the board enough that half the surface mount parts fell off. Used a strip of thin solder next to the board to get a guess on temp 3 Quote
Lord Gruntfuttock Posted February 20, 2018 Posted February 20, 2018 On 15/02/2018 at 21:15, tortron said: got stuck in some mousetrap Barry clips the other day. Had look from your link. Mousetrap Barrys indeed. Sad thing is I watched about a dozen of them before snapping myself out of it.. 1 Quote
h4nd Posted February 20, 2018 Author Posted February 20, 2018 On 2/19/2018 at 21:58, NickJ said: Used to have to do that monthly to the logic board in my Macbook, worked flawlessly until I put it in a glass roasting dish with a convex base, just twisting the board enough that half the surface mount parts fell off. Used a strip of thin solder next to the board to get a guess on temp Yep, watch the radiant from the element, temp can be higher than on the dial. 1 Quote
NickJ Posted February 21, 2018 Posted February 21, 2018 4 hours ago, h4nd said: Yep, watch the radiant from the element, temp can be higher than on the dial. That jogs the brain, I used tin foil to shield the plastic sockets etc, should have been ok, but I wasn't keen on taking too much risk. 1 Quote
Popular Post two_days_late Posted March 6, 2018 Popular Post Posted March 6, 2018 Thought I'd chuck up a post for these roof racks we just cleaned up for a mates mini (mainly because it's a really cool old mini). We wanted to be able to get 2 full size mountain bikes on the roof but keep it looking old school. We set out to find something to use as a starting point and thankfully @Steelies has just the thing. Racks when I picked them up Just needed a good tickle up with the wire-wheel, a couple coats of satin black rust kill paint, and all new allen head bolt for max style points. Then found online these alloy transport/storage mounts that act as a fake hub so you can just whip the front wheel off the bike, and bolt the fork straight to it using the bike axle. Plus some nice titanium bolts to hold them on And she's all ready to roll Not the most complicated project, but means the old beast can keep doing it's daily duties! Cheers Matt 14 Quote
JoKer Posted March 6, 2018 Posted March 6, 2018 really need a pic of it loaded up now for the full effect pls 8 Quote
a.craw4d Posted March 8, 2018 Posted March 8, 2018 Given random pieces of steel so made a seat. 4 Quote
Steelies Posted March 8, 2018 Posted March 8, 2018 i am now going to bake every electrical thing that fails. log in to dwindling bitcoin account, put laptop in oven and bake till crispy brown on top = profit 7 Quote
BlownCorona Posted March 9, 2018 Posted March 9, 2018 gin traps for foot rests, nice. hope the welds dont fail 2 Quote
a.craw4d Posted March 10, 2018 Posted March 10, 2018 On 3/9/2018 at 13:24, BlownCorona said: gin traps for foot rests, nice. hope the welds dont fail There's quite a bit of weld on them but it's mostly out of sight. Feels a little funny sitting in it bare foot though. 2 Quote
flyingbrick Posted March 10, 2018 Posted March 10, 2018 On 2/19/2018 at 21:58, NickJ said: Used to have to do that monthly to the logic board in my Macbook, worked flawlessly until I put it in a glass roasting dish with a convex base, just twisting the board enough that half the surface mount parts fell off. Used a strip of thin solder next to the board to get a guess on temp Unfortunately solders can melt at vastly different temps. Iv had some that didn't want to melt at all with iron until i put normal solder on top (may have been a different issue?) Quote
NickJ Posted March 10, 2018 Posted March 10, 2018 9 minutes ago, flyingbrick said: Unfortunately solders can melt at vastly different temps. Iv had some that didn't want to melt at all with iron until i put normal solder on top (may have been a different issue?) Apart from specialised cases, all electrical solders have a melting point around 200degC (true eutectic is 190 from memory) the biggest issue is getting heat into a joint, if you have two convex surfaces (iron tip and joint) then the heat path is minimal, a dab of solder increases the heat path area and all is happiness. In extreme cases, the eutectic may shift from compositional changes, this can happen in brazing, where once a part is flowed, it takes a higher temp to release the joint, but i'm unsure if this is documented in solder? 1 Quote
flyingbrick Posted March 10, 2018 Posted March 10, 2018 Dunno but i have had faulty pcb's with dry looking joints that were a nightmare to reflow i assumed it was some special higher temp solder used by professionals. Quote
h4nd Posted March 13, 2018 Author Posted March 13, 2018 You may be up against ROHS (Reduction of Hazardous Substances) lead free "solder". It has no lead, and melts at a noticeably higher temp. Quote
Popular Post two_days_late Posted March 19, 2018 Popular Post Posted March 19, 2018 By popular demand.... 23 1 Quote
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