Repairing modern electronics - BGA rework, anyone?

[Eric The Viking]

There's a story in the Telegraph today about a government "energy advisor*" saying we should repair more stuff and throw less away.

It made me laugh out loud. He's not wrong about the value of repair over replacement, but his government should be dealing firmly with the manufacturers, not berating the poor consumers, who have to buy what's available.

I fixed daugher-in-law's laptop yesterday with a £2.65 part (thank you eBay!) and about an hour of frustrated fiddling with lead-free solder removal. Installing the new power socket took less than a minute. You'd think the motherboard was deliberately designed to break, though, if the owner was at all careless with the connectors.

Anyone tried to do ball-grid arrays themselves? If so, how did you get on?

Our £1000+ TV has a BGA going sour on the back of the display. I've had a cursory look: it's only about four years old, and frankly designing it that way is a disgrace - it's in almost the hottest place on the set, and you could guarantee that it would have failed any proper environmental testing involving thermal cycling, yet it was still put into production. It's a very major brand name.

After doing the laptop, I concluded that investing in BGA repair kit (hot air soldering station, BGA clamp, thermocouples, etc.) might be cost-effective, as these problems will only get more common. I've seen a lot of boards, though, that have other components mounted on tracks going across the middle of the back of the BGA. Presumably these would fall off or be compromised if you tried to heat the BGA chip carrier on the other side. There must be a process for reworking this arrangement too, but I've so far failed to find any YouTube how-tos.

Anyone else invested, or used BGA rework kit, perhaps at work? How do you get on, and is it hit and miss, or just a matter of careful process?

E.

PS: Is it me, or are the 'premium' brands no better made/designed now than the cheaper stuff? It seems to be down to design and marketing rather than engineering nowadays (TVs, tablets, cameras, etc.).

*oxymoron

 

[RogerS]

EtV...can't help re BGA but think you are a braver man than I to attempt such a task.

Had a quick look at that article. Methinks the Professor needs to get out and smell the coffee. The scary thing is that he is the Govt chief scientific adviser. Having said that, like you, I always look at the possibility of home-repair and have, by buying secondhand units off eBay, been able to keep our Sony surround sound system working for well over fifteen years (IIRC).

As to reliability of premium vs cheap? Not sure. Some would argue 'no' as many components are common and built in the same factories (maybe...maybe not). Guess it depends on the item. Kettle vs computer, for example.

Is an 'oxymoron' someone who has dropped out of Oxbridge?

 

[MMUK]

I've a Pace 8007-0455 soldering/desoldering/re-work station. Bloody good bit of kit. I bought it a few years back when I was building custom ECUs/TCIs for race bikes. Doesn't get much use now but when it does it's very handy.

The same model is available from Farnell for about £1200 +VAT but I bought mine for £900.

 

[tekno.mage]

So far as I can tell modern equipment is not designed to be repaired - they just want you to spend more money and replace anything that breaks and if it breaks down more quickly because of poor design, so much the better (for the manufacturer).
Good luck with trying to fix that BGA.

 

[MMUK]

So far as I can tell modern equipment is not designed to be repaired

You've (hammer) the nail on the head (excuse the pun on a woodworking forum).


Throw away society :roll:

Personally I like to try and repair everything I can. However it's getting more difficult to keep it economically viable. Certain spares are prohibitively expensive for low quantity purchases that it makes more financial sense to replace for something with a two/three year guarantee.

 

[Eric The Viking]

I've a Pace 8007-0455 soldering/desoldering/re-work station. Bloody good bit of kit. I bought it a few years back when I was building custom ECUs/TCIs for race bikes. Doesn't get much use now but when it does it's very handy.

The same model is available from Farnell for about £1200 +VAT but I bought mine for £900.

Thanks a lot for that. I'll keep an eye on fleabay.
There are quite a few out there new, at the £500 mark, but one wonders about the quality.

I get the feeling everything is down to good timers and a lot of good thermocouples. The re-soldering doesn't look too hard, it's the de-soldering that frightens me a bit. I'm unconvinced by IR top heating, too - it looks a bit hit+miss. There's one product demo on YouTube that unintentionally shows the operator actually destroying most of a motherboard by boiling the capacitors nearby and melting a connector!

E.

 

[MMUK]

De-soldering isn't too daunting really, it just takes practise. I started out using scrap circuit boards from a skip so it didn't matter if I cooked anything. There are chemical sprays available to freeze critical components to prevent overheating during de-soldering and rework.

 

[Eric The Viking]

Freezer sprays - I'd forgotten them! Jolly good idea.

And yes, sadly I have quite a few boards to practice on too.

 

[mind_the_goat]

Been a while since I did any serious pcb rework. I guess your success might depend on the type and quality of the PCB. I do remember lifting tracks was a common problem and multilayer boards can be quite fragile. Freezer sprays seem a good idea and it sounds like they can work, but do they not cause more thermal stress making damage more likely?
There are a number of people now offering used PCBs from TV's and other items, I recently repaired our TV with a replacement PSU board. Even found some reasonably priced new boards on offer.

It's is good see an advisor raising the issue, unfortunately this government has a poor record of listening to it's scientists. As you say there is a serious problem with pricing designed to encourage buy new rather than repair, as anyone who has looked at drill battery prices compared to new drills will know. It would be great if we were actually allowed to take old electrical items from the local 'recyling' centres in order to fix other things. They seem reluctant to let you have electrical items at the moment. I think someone else on here reported that his local centre would not resell bikes in case someone hurt themselves. That leaves Freecycle and related groups, which can be useful a source of bits.

There is community movement called Repair Cafe, started in the Netherlands, I'm quite keen on starting one up in my area. Basically a volunteer run group that offer to help people fix their stuff, with emphasis on 'help'. A great way to remind people things still can be fixed.

http://repaircafe.org/

Anyone in Dorset want to join in ?

 

[mind_the_goat]

Just read the full text of the telegraph story and all members of the government are entering to sensible debate about the idea:
Clearly has a high opinion of FoE, a group of people who do actually give a ....pineapple, and listen to their own scientific advisors. I'm not saying his point should not be taken into account, but if politics requires wining arguments by putting down anyone who doesn't hold the same views, then I can see why people don't vote anymore. What's wrong with knitting socks anyway?

"Peter Lilley, the Conservative MP for Hitchin and Harpenden who sits on the Commons energy and climate change committee accused the professor of “shooting himself in his policy foot”.
He said that projections have shown that “more efficient” appliances could lead to a 27 per cent reduction in household energy use.
“If we repair the inefficient ones we will consume far more energy,” Mr Lilley said.
He added: [Prof MacKay] should either decide whether he’s chief scientific adviser [at DECC] or whether he’s going to join Friends of the Earth and knit his own socks.”

Anyone in his constituency care to ask him why most energy efficient appliances cost 3 times more than less efficient ones, so that most people can't afford to buy them? Also be interested in a reference to study that has the the 27% figure.

opps, straying into banned topics, but would just like to add I don't support any of the major parties or the ones on the extreme edges.

 

[RogerS]

You have hit the nail on the head there, Rob. All these politicians have personal agendas. Lilley, because he wants to be seen to be pushing green things. Such a shame that they all fight their own little fiefdoms.

 

[doorframe]

Spent the first 15 yrs of my working life as a TV/Video/anything electronic repair man. 10 of those years self employed. (anyone remember Radio Rentals). Gave it up 18 yrs ago as it was already a throw away world. It was supposed to be a job for life.

Regarding the BGA, I did a mate's laptop about a yr ago. The GPU chip to be precise. I masked the mobo with silver tinfoil leaving only the GPU exposed and hit it with a heatgun. The GPU didn't need replacing, only re soldering. Quite a common trick according to the internet. To do the job properly without the correct equipment was a total non starter. Lasted about 8 months then it went in the bin.

 

[Jonzjob]

Funny that this has come up now? I am awaiting 25 capacitors, from the U.K., of which I need 3 to repair our Paranoic DVD recorder. 25 because they come in 10, 10 and 5 packs so I'll have a few spares :mrgreen:

It wouldn't power up all of a sudden and on a google search I found a forum that gave the exact fault and solution complete with the bits needed. There's a forum for wiping yer bum these daze init already??

They even said that it isn't necessary to take the main board out, a sod of a job, just to cut the descrete wires off at the caps and solder onto those. That should keep the heat away from the board as well. Win win ?

Good when you can repair instead of chuck and buy me-thinks :mrgreen:

 

[Eric The Viking]

Spent the first 15 yrs of my working life as a TV/Video/anything electronic repair man. 10 of those years self employed. (anyone remember Radio Rentals). Gave it up 18 yrs ago as it was already a throw away world. It was supposed to be a job for life.

Regarding the BGA, I did a mate's laptop about a yr ago. The GPU chip to be precise. I masked the mobo with silver tinfoil leaving only the GPU exposed and hit it with a heatgun. The GPU didn't need replacing, only re soldering. Quite a common trick according to the internet. To do the job properly without the correct equipment was a total non starter. Lasted about 8 months then it went in the bin.

I'm thinking of doing that with our TV. It's the rasterizer chip that's gone, I think (Samsung panel), but it might be the driver circuitry closer to the LCDs. I'm getting very thin permanent vertical lines, and occasionally as it heats up we lose about a third of the screen in a vertical stripe.

I've just ordered a couple of thermocouples and LCD display thermometer, and I'm planning the same thing - surround the chip with foil and carefully hit it with a heat gun. It can't make matters worse.

I've also just ordered a stack of low voltage large value caps to try to repair two PC PSUs. I've got quite a few of them already, but one of these PSUs is infuriating, as it's physically very small, and caps from other PSUs won't fit.

Ho hum.

E.

 

[Sheffield Tony]

Good luck. The foil trick sounds worth trying. I recently tried to replace some chips which were not BGA, but a power QFP with a single large ground pad under the chip. Attempt #1 (practice on a totally duff board) sent a shower of 0402 resistors/capacitors flying every which way - definitely you can make matters worse ! Second go successful - the heat transfer pad on the PCB was heavily connected by vias to the back. so I could get heat on from both sides. Extra limbs would be useful.

 

[RogerS]

Frustrated with the difficulty in resoldering his BGA, EtV resorted to alternative forms of heating

 

[Eric The Viking]

Bloomin EXCELLENT!

 

[RichD1]

Having worked in Military/Avionic electronics all my life, BGA rework is impossible without a good BGA rework station which probably now cost around £5K at the low end and then a few years experience on how to use it. On top of this there is now the lead or no lead solder issue. You have to know what was originally used to get the right heat profile to de-solder in the first place.

Richard

 

[RichD1]

Oh, forgot to mention, once you do get it soldered back in place you then need an X-ray inspection machine so that you can inspect for completed solder joints. Starting price around £10K!!!

Richard

 

[Eric The Viking]

It's lead-free. That's why it failed in the first place, most probably.

There's an exemption for aviation applications, and, I think the motor industry, but all consumer products now have to be lead free.

I'll try to get by without the x-ray machine...