Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

My eyes and mind failed me... :-( The chips DO have a ground plate. I thought it was just a small label on the backside but alas, it is not. Now how do I remove the chip without over heating / burning the board and other components especially on the other side of the board????

As you, Diif, indicated, chipquik does not help as there is no way to put it on the ground pad. :-(

[diif]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

Why would you be burning the board ? What temp do you use on your hot air ?

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

the hot air is set at 400F and about "3" air flow. I didn't do my practice run on my other board with any hot air. I just chipquik and a soldering iron. On the "target board", that didn't work. That's when I "relooked" more closely at the new chip package and saw that it wasn't a label but a pad on the bottom. So I guess I need to heat the whole chip up enough to heat the underside / pad of the chip to melt its unreachable area.

Of course, the other question if I get the thing off, is the "reverse" process of soldering the pad back onto the broad.... flux, tinning, and heat???

[diif]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

400F is 204C, lead free folder melts around 218C, you might be a while..
I'd remove all the solder with wick, and add a little leaded solder to the ground pad. This reduces the temperature required to reflow it and reduces the risk of damage.
Hot air to solder the chip to the ground pad, then drag solder the pins.

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

400F is 204C, lead free folder melts around 218C, you might be a while..
I'd remove all the solder with wick, and add a little leaded solder to the ground pad. This reduces the temperature required to reflow it and reduces the risk of damage.
Hot air to solder the chip to the ground pad, then drag solder the pins.

OK... thanks. I assume your "hint" is for soldering things back. To get the existing chip off, I just need to move my heat up a bit further and keep heating the damn thing tell the underlying pad / solder release... right?

[diif]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

My hot air is on 380c, I'd remove the chip using that.
Perhaps practice some with your scrap board.

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

thanks... I got them off. One came off OK although I had a problem with "solder splash" when I tried to move / take the chip away from the area. I hope I got everywhere it splashed :-(
The other one came off but it appears that not all the pins released or were "wet" / heated enough. As a result, I now have track problems where a couple of pin pads pulled away. :-( I think 3 of the 4 are almost in the right place... the one in the top right corner is bent ... It was worse, as it was totally over to the other pad. I tried to move it over to correct. When this area was first seen (after the chip removal), there was a "pile of solder" there. Both the end row pin and the one in question were "displaced". :-( I think that I got the end pin pad back but this other one is difficult because the pad is bend and I can't do much as I need to have it hot / heated to be able to move it at all.

This perhaps might be the end of the effort. Ideas on how to recover from this "poor workmanship experience"? :-(

Hope the picture is viewable... it might not be clear enough to see the problem. I need to do a bit more clean in various areas but at this point, I don't see any solder bridges anywhere.

[diif]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

You can scrape away some of the trace and solder a wire to the leg or use one of these https://www.aliexpress.com/item/1005003630372619.html first and put the chip on after.

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

thanks... never seen such a beast. Need to figure out how it is done and whether it can work for me.
one question, what is holding the replacement pad that you linked... some form of thermal set glue or only the track that it is connected to?

I was able to straighten the pad / tracks.... but I assume that there is nothing holding them down to the board any more as what ever bonding agent is gone. IF I was to drop the chip on the existing loose pads / track, would it stay in place or is this a bad idea?

[diif]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

If there are no missing pads and they were just pulled away from the board and are still connected you are ok. I miss understood and thought you'd ripped the pads off.

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

OK. thanks. Phew!!! hopefully, the soldering back on will go ok. I still have to think about the re-soldering as I need to work the ground pad first without misaligning all of the outer pin to pads... and not over heat / cook the new chip.... hopefully the lead solder will help with a lower melt point.

As a result of removing the chips and then retesting back at the hdmi pin on their connectors, especially comparing the "known" non-working ports (in 1 and out 1), I found that one of the ESD diode packs in the IN1 was bad... low resistance to ground as compared to other working ports. I had previous removed this particular set prior to the "big chip removal'... at the start of this exercise... so it was bad but also at the big chip itself... at least I think that what it indicates. Anyway, I will change out the esd packs of those that are not reading correctly now that there is no other component in the path.... in most cases on the board between the ports and the IC's in question.

[diif]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

Can i see the back of the board where those ICs go ?

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

This is the backside. I took this just in case some components fell off during work on the other side.

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

So I "tinned" the board ground pad area along with the chip ground pad. I tried to keep the tinning "thin" but that is pretty hard to do on such big contacts. Just "dry fitting" the chip to check alignment across the pin aray. Looks good. My question is: will the chip "sit down" once I heat the center / around the area of the chip once things are hot enough to melt the leaded solder? As it sits cold, you can see that it is "slightly proud" and as a result most of the outside pin array is not touching the board pads. I am hoping the "sit down" will pull it down enough to have those contact the pad in the next stage of soldering. Do I have to "light" push down of the chip to aid the "sit down" while heating / at melt point?

[diif]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

I wouldn't have tinned the ic ground but it should be ok, you might have to apply light pressure.

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

No success yet... :-( I am significantly concerned about how hot I have to heat the chip up to get it to transfer thru to the ground pads to melt / flow the solder down there. I am running at about 300c hot air. So far no luck other than the flux melting. My thermal ir detector / imaging seem to indicate a 200c "surface"... but maybe that is not enough to get thru to the underside. Or perhaps not long enough?

I can see this is a technique that it provides a "lot of fear" for "first timers". :-) Not much different than the "fear" coming from a soldering iron technique but maybe just a bit more experience there provides more backdrop for the mind to be at ease.

[diif]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

Yes, not hot enough. or long enough if it's not melting the solder.

Use your practice board, turn your heat up t0 720F.

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

Yes, not hot enough. or long enough if it's not melting the solder.

Use your practice board, turn your heat up t0 720F.

Thanks... hopefully I didn't overheat the thing too much. I got it at least mounted... not yet attempted soldering the side pin array which should also be fun.

There is a "slight" misalignment (ie. not perfect) on two sides (right and left sides in the picture). The chip probably needed to move ever so slight up (in the picture)... but just getting it to where it now sits was more than difficult for these old shakey hands... :-) There is NO pin "cross overlap" (ie. touching an adjacent pad) but the "slight offset" may cause problems in the next step of trying to solder the side array pin without bridging... I hope not.

I haven't tried mounting the larger / more pin array chip just yet as I thinking on this some and maybe do some testing around this chip. I would think that there should be some pad contacts happening even without soldering.... maybe. I am hoping I can do a "compare readings" across the two hdmi input ports to see if things changed with "all" this effort.

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

Did some practicing on my sat board chips in terms of soldering on the removed chips. Major difficulty in preventing bridges across pins. Lots of fluxing and trying to draw solder away. Decided to try one side of the new chip on the target board. Probably a bit of mistake. Didn't use any extra solder other than what was on the tinned solder tip. Ended up with a bridge of the last three pins (right side in picture above). I tried to draw away the bridge with a very clean tip and flux. Some where along the way with the effort, I appeared to have lost the pad under pin 38 (second pin from the bottom end). :-(

Now I have to decide if it is worthwhile continuing and / or seeing if I can jumper (a very little jumper) to that pin from some point. If I read the schematic right, 38 is a feed of 3.3v. Further, to complicate this a bit more, the two pins 38 and 39 are not directly connected in the schematic as far as I can tell BUT the meter reads a connection. Upon looking at the schematic, pin 38 is connected to "3.3H" while the other is connected to "3.3 HSWPLL". How can I tell if my meter is just reading a "common" impedance back to some 3.3 source somewhere as opposed to a solder bridge (say maybe underneath the pins... or my "lost pad")?

[budwich]

Re: Yamaha rxa2070 lost hdmi out 1 and in 1... :-(

based on the schematic, the two "feeds" are going to different regulator chips in the power area. That would seem to suggest there shouldn't be on any continuity between the two. :-(

update:
I think that I was able to get in behind the two end pins and lift them a bit away the board (while heat was applied). After a bit of flux and clean tip, the "missing pad" seems to be back under the pin 38 and there doesn't seem to be any measured connection between it and 39 after lightly resoldering. Great... I hope.

update: hope was fleeing... maybe as there seems to be still continuity across the pins in question and maybe even a few more (next ones over)... not sure if they had that before I started fiddling around... :-( maybe I have damaged the chip internally.