Advice for a new BGA rework station owner please

[dicky96]

Originally Posted by Spider1211

When doing BGA reworks, ensure a fairly constant environment around the machine. Even a light breeze could affect the profile.

That much I can guarantee because if I use the BGA machine when the aircon is turned on it trips the power out!!

The office is always somewhere between 21C and 30C or so and breeze does not exist here for the main part lol

I bought a BC2M, but rather like the way the BC3 works because it has a larger area. I'll get a BC3M on your suggestion and see how that works, cheers.

[Spider1211]

The BC3M should help with the 'solder rolling' but will also use up your wick faster since it holds more solder. The larger tip is better when you have larger areas to clean and when the board is cool.

The hollow center tips are great for QFP. The BC2M should be more than enough for that. But its also good to have more tips, never know when you might need them

[dicky96]

Originally Posted by Spider1211

But its also good to have more tips, never know when you might need them

100% Agree

I was going to try fit a replacement LGA1151 yesterday only to find the camera on my optical alignment system has stopped working!

I know it is either the camera or the HDMI lead because I plugged an external video source into the alignment monitor on the G720 and that works

Unfortnately on the lead built into the machine, the end that goes into the alignment unit is captive and I can't see an easy way to dismantle it. I've emailed LY CNC in China yesterday to see what I need to do. They already responded asked me to send them pics or a short video link showing the problem.

Rich

[dicky96]

So the camera on my machine is faulty - despite being only three months old.

I checked the monitor with another video source and another HDMI cable with the camera, it's definitely a problem with the camera

LY said these cameras are very expensive, around $900, but they would send me a replacement camera if I paid $250 (about 220 euros) as they claim their warranty does not cover the camera! After a bit of to-and-fro emailing they then said they would send me a replacement for 180 euros on TNT express delivery andthey have in stock for immediate shipping.

When I bought the machine, to be honest I never asked about warranty. I've asked now and they did not answer that question but when I challenged them on the warranty if I do pay for another camera they said it would be covered under warranty for 12 months!

Given that, I honestly don't understand what the issue is with warranty the original camera, I do realise I should have asked about warranty prior to purchase in the first place. But it does seem a bit shady to me.

Anyway the top and bottom of all this is I need to get my machine working even if I have to pay for a new camera.

I've taken the old camera out of the machine. It was mounted on a slot with a bolt so it can be moved backwards and forwards, presumably to do with focusing though in actual fact when it was working it has auto focus. I made a mark so I know where it was fitted. It was locked tightly in position with a bolt.

I posted on this thread regards the camera
https://www.badcaps.net/forum/showthread.php?t=83208

Anyone interested in what is actually inside an optical alignment system, or knows anything about fixing cameras, go and have a look

If it is something I can fix without too much hassle then it would be good. Or if this is a 'generic' camera that I can buy cheaper than 180 euros elsewhere that would also be satisfactory. Failing that I guess I have no other choice than to pay LY for a new one.

[Spider1211]

Warranty is one of those grey areas when buying from china. My guess is, even if you had asked about warranty prior to purchasing, you would still be surprise if you were to claim it afterwards.

I had similar issues with my co2 laser cutter. I ended up troubleshooting and repairing it myself even though it's under warranty. You'ld be surprise at how simple something might be to repair even if you never did it before. I suggest you try repairing it yourself.

Furthermore, the sellers often claim you need to buy from them for compatibility issues etc when they often use generic rebranded stuff.

Is using the camera a must? Am guessing there is a manual mode where you can still use the machine.

[dicky96]

Yes I can use it in manual mode without the optical alignment but they that kinda defeats the object of buying a semi auto machine in the first place

My whole intention of buying this machine was to have reliably repeatable repairs, or at least have a better chance of achieving that.

[dicky96]

OK so I got the alignment camera working again, though it is somewhat intermittent like before and may work for 20 mins then cut out

As a first attempt of mounting a BGA I want to fit this LGA 1151 socket. I already successfully removed the old one with broken pins

So I did ask this before - how to tell if the replacement part is leaded or unleaded solder as it did not say on the aliexpress listing.

I took some pics, and because I didn't have anything to compare with I put a blob of leaded and unleaded solder onto an old bit of veroboard as a comparison (leaded 60/40 is the top blob). Looking at that, to my untrained eye, I have unleaded solder on the replacement LGA 1151?

What would happen if I soldered an leaded part using an unleaded profile? The solder would still melt, though it would get hotter than necessary.

Would there be any harm in doing that if I wasn't sure?

[dicky96]

As no one seems to know, I decided the LGA 1151 was probably Lead free so I soldered it using the same profile that I used to remove the faulty socket from this motherboard.

it was a spectacular failure. It wasn't an actual disaster as I don't appear to have damaged the motherboard but I hoped for better results than this

So after soldering it looked like I may have teh LGA slightly skewed even though it looked good on the optical alignment. I checked this out by looking up the LGA1151 pinout and checking if I had Vcc and Vss connected to various pins in each corner - and I did not

I then noticed that the LGA wsa not firmly attached to the board. So I removed it using hte same profile which worked fine

On removal it was obvious that
A. My alignment was spot on
B. Most of the balls had not soldered. Some had towards the edges/corners and I had ones solder bridge.

Before soldering I gave the PCB a light coat of NC-559 flux with a paintbrush

I'm desoldering and soldering the LGA with the pin shield in place otherwise the vacuum can not pick it up

I attached a short video and some pics, sorry the one of the profile is not very good but you can read the temperatures. This was taken when I tried to solder the LGA. The video was taken after I removed the flux from the PCB

https://youtu.be/DG0rDZrVCfo

Where am I going wrong now?

[diif]

You're measuring the temperature of the probe in an area exposed directly to the hot air.
I don't imagine the plastic is particularly good at transferring heat and with the pin shield on the hot air is blown around giving poor heat transfer.

Try again but without the pin shield. You might need to add longer dwell times between ramping up to allow the heat to get to the balls.

[dicky96]

Hi diif
What I can't figure out is how to use the optical alignment) - which obviously worked perfectly according to the balls soldered in each corner - without the pin shield fitted.

Sure it is clear I didn't get enough heat in to melt the balls - but the same profile desoldered the old LGA from the same board with no problem. And I desoldered it with the pin shield fitted (took it from the new LGA socket).

That seems strange, to me.

I will try again with longer dwell times, like you say, rather than increasing the temperatures.

[taitogr]

This might help. a HOWTO************** video...

MOD EDIT: SPAM !

[dicky96]

Cheers taitogr
I'll take a look at that. As the current near lock down is not conducive to me doing any business at the moment, I'm about ready to come back and spend some time trying to get this working this time.

Rich