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

**diif** · 11-15-2022, 05:16 AM

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

If you download the datasheet you will see that it's pads are at the edge of the diode, you're just seeing solder, it has no side pins.
I see no issue in removing them with hot air, just don't melt the HDMI socket.
4M is it's marking the 7 is a date code.

**budwich** · 11-15-2022, 06:32 AM

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

thanks... I never even thought about the proximity of the hdmi socket and the "phenol" associated with the socket. Good point.

**diif** · 11-15-2022, 06:57 AM

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

"phenol" ?
There are inductors above the diodes and caps to the left, don't have the air speed to high, you could blow them away.

**budwich** · 11-15-2022, 02:07 PM

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

Phenol -> phenolic plastic that the body of the hdmi connector is made of. It could melt or deform with heat depending on how I aim the air in the tight space. Yes, I am also worried about inadvertently blowing away small components in the area. I have set the air flow at about 30% so hopefully that will keep the "wind down".

**budwich** · 11-15-2022, 03:15 PM

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

hmmm... so I removed the esd packages from the hdmi input 1 (3 4m7's). Now the problem is getting the new ones in place. How do it get new solder on to such small tracks / board pads for the new smds to sit on and ultimately melt with the heat. I haven't been success with a small tip soldering bit to try "tin" some new solder on with the hope it will migrate well on to each track. Surface tension of the tip seems greater than that of the track / pad and so the solder doesn't really want to travel away from the tip to the board. Paste flux does not seem to help much.
What am I missing? Are you suppose to try "tin" the smd pads before attempting the install?

**diif** · 11-15-2022, 04:09 PM

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

What iron do you have ? You might be better off tinning the pads on the diode and reflowing back with hot air.
it's not a good idea to mix leaded and lead free solder, tin the pads with lead free.

**budwich** · 11-15-2022, 05:18 PM

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

I have a temperature settable soldering station. I using a small pointed tip.... but the tip is only about the size of half the smd.... maybe too big but I don't have anything smaller. I will try tin the pads if I can without losing the smd in the solder tip.
I don't think that I have any lead free electronic solder at this point. That's probably the issue... them not playing well on such small traces / pads.

**diif** · 11-15-2022, 06:51 PM

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

There should be no problem soldering the pads with either leaded or lead free. I'm a fan of the micro j tip, it can do multiple or individual pads.
Do your tips have the heater in them, you will struggle with sleeve type tips.
You might be better off just using flux and hot air and the left over solder on the pads.

**budwich** · 11-16-2022, 07:34 AM

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

thanks... no joy here... :-( Attached is a picture of the removed esd package areas for hdmi 1. Those are damn thin pads. In terms of your questions, my soldering tips are "sleeve" types. As you can see there is very little solder that is left over on the pads / tracks. During my "practice" on some other boards with "small fet" type smds, I had no problem with demounting and remounting / soldering with existing solder left behind... but it is likely those boards might have been leaded solder (ie. older boards).
Anyway, the "BIGGER" problem is... I decided to do some further measurements once the esd diodes on hdmi1 were removed to see what was happening there in since the tracks basically "passby" the esd smds which act as some form of shunt to ground. Originally, based on everything as designed / left in, and comparing with results to the hdmi inputs, I thought the esd diodes were shorted / "done" on hdmi1 as both resistance and diode test measurements did not compare well (most were very low to 0) with "working" hdmi input ports. BUT with the ESD diodes removed and doing the same testing, the measurements are the same which likely means that the main hdmi chip is hosed also. It is not within my skills to remove and re-install this type of huge "BGA" even if I could find one (the service manual indicates "part not available").

I have to contact yamaha and see if there are any option and at what expense. :-(

Attached Files

**diif** · 11-16-2022, 10:09 AM

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

Does the diode check short out of circuit ? You have nothing to lose apart from some time, having a go at replacing the HDMI IC, lets see it.

**budwich** · 11-16-2022, 12:31 PM

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

as you can see from the previous picture, the esd diodes / package has been removed so the tracks from the hdmi connector go straight thru to the hdmi switch ic (just to the top right). With them gone, the tracks still measure the same as they did with the old diodes installed ... ie bad... (as compared to other working hdmi inputs). I don't even know how to get at the thing / can off. The IC itself is an mn864788 (144 pin "monster").

Still further, it is likely the output ic (mn864787) is also bad (lost output 1)... so the effort would be to remove that also and find a replacement. That is probably going to cost some money if they can be found ($100 or more... guess). Based on my first experience, it is likely that the diodes are fine and that the actual problem lies with both IC's... :-(

As you indicate, I have nothing to lose at trying to take them apart other than perhaps time. It would be a learning experience. Heck just putting back the esd diodes will be a "curve".

Ultimately, it comes down to throwing money at things with a significant risk of being unsuccessful. The cost of a replacement card is significant (>$700) and its on back order by 2-3 months.

Still further, is that the unit "kind of operates" with the remaining 6 hdmi inputs and one output although, it does seem to have some "video stability issues" (syncing / strobing / lines in the picture) depending on resolutions involved as probably the health of the IC's involved might be very questionable.

I have to think about this a bit more at this point. I do appreciate the pointers that have been provided. My learning curve could always use some "twisting".

**diif** · 11-16-2022, 12:47 PM

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

If the diodes are fine, put them back before they are lost. No need to add solder, none has been removed, just add plenty of flux and use hot air.

It's QFP, not BGA, around $15 from Ali.
It wouldn't be to had to replace.

**budwich** · 11-16-2022, 01:26 PM

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

"it wouldn't be to hard to replace"... that might be easy for you to say but I am not feeling so much at this point. :-)

I still have to figure out how to get at those without breaking some more. You seem to indicate that those ic's are available and are "drop ins" without any programming required (beyond my skill).

As for the esd packs... I still have them so I will try put them back as they are.

**budwich** · 11-25-2022, 07:16 AM

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

I ordered the two QFP's (mn864787 and mn864788). The 2070 functions but the output on hdmi 2 is unstable at times especially if the source has changed resolutions.
As you, diif, said I have little to lose ($50 in parts) and maybe $20 for chipquik to help with the qfp removal. Hopefully, they will address all the issues without creating new ones.

Not sure that I understand the service manual indication of "no replacement part" for those items. Is that because, at the time, there were none being offered / made or is there something special about those that a "generic" replacement can't fulfill?

**diif** · 11-25-2022, 07:24 AM

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

I'd wait for your chips to arrive, if they have a ground pad then save your $20 on chipquik, it won't help.

I think it's suggesting there are no alternative ICs, rather than no replacements available.

**budwich** · 11-25-2022, 04:16 PM

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

ok.. thanks. that's good to know... both the "removal tip" and the parts "description". IF there is a ground pad, then I assume the hot air method is the mode for removal (with flux) and "praying"... :-)

**budwich** · 11-28-2022, 08:39 AM

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

even having fun trying to get the heat sinks off the two chips involved. They have two soldered lugs (one on each corner). Was hoping to heat one lug at a time and slowly "rock" it away..... but with the unlying thermal pad on the chip holding on to things, the heat sink ain't budging at all. The "lug / tang" fits into grooves in the heat sink fins so they can't be readily slid / bent away. Any idea on replacement tags or what they are called. I was thinking that I could cut them, then remove the heat sink and then ultimately remove the remaining portion to the tab / tag and replace there after.

Normally, when I have removed a heat sink from a chip that has a thermal pad, I do a slight twist to break the "adhesion" of the pad, but this can't be done with these heat sinks soldered in place.

Attached Files

**budwich** · 11-28-2022, 09:52 AM

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

I was able to fashion a plastic "pry" to help lever the heat sinks off, one side and then the other.

The removal of the two chips doesn't look like fun... yikes really small pins and lots of them. :-( I hope my "skills" will ramp up faster than my "destroy capabilities"... :-)

Attached Files

**budwich** · 12-06-2022, 09:24 AM

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

got my chips delivered, so its on to the next step. Related to a question earlier, both chips are "simple qfp's" with no ground plate on the back.
I did a practice run at removing a qfp off of an old sat board that I had lying around. Somewhat scary. Using the SMD chipquik for lead free solder. I have to check on the temperature of my soldering tip as when it hit the flux that I put down, it almost seem to "evaporate" as I expected it to melt / flow. "Dragged" some chipquik solder along each side of the qpf. Most seemed to end up at the top of the pins of the qpf as opposed to near the board solder points. Lightly dragged the solder tip around the four sides a couple of times, could see the solder was shiny longer and longer. Gave a corner of the chip a little tug with a pick and it popped off the board. WHAT! Was surprised at the "ease" of the operation. I still need to check temps some more but it appears that I might be successful at this stage in the learned technique of qfp removal.

I guess one question is: can I help the removal process by adding a "supply" of hot air towards the chip once things are "flowed" with chipquik solder or is there a danger that too much heat might be "misdirected" at surrounding components (which are fairly close by on a couple of sides) either blowing away or overheating? Probably most go with just a solder iron and working fast / steady.

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

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

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