urc-9910 B01 buttons not working

[gpeck]

I have a URC-9910 that some of the buttons suddenly quit working (yes suddenly! I fell asleep and all was well...I woke up and they didn't work). I thought perhaps I fell asleep on the remote and re-programmed them, but that was not the case. I checked the config with ir.exe and they are programmed to what they should be. So, I took the remote apart and cleaned the contacts. Still did not help. I could not see anything on the board that looked bad.
The buttons that don't work are: SAT, CBL, Menu, 1, 2 & Enter.
Anyone have any ideas what else I might try?

Rob:
I bought this remote from you almost exactly 2 years ago (11/29/04), if there is not an easy fix, would you want to do any type of discount on a swap with a new one?

[johnsfine]

The buttons that don't work are: SAT, CBL, Menu, 1, 2 & Enter.

You mean 3 and Info work??

The buttons SAT, CBL, Info, Menu, 1, 2, 3 and Enter are an electrically associated set of buttons. A specific broken run on the PCB would wreck those 8 buttons and nothing else. But wrecking 6 of those 8 is very unlikely.

[The Robman]

Rob: I bought this remote from you almost exactly 2 years ago (11/29/04), if there is not an easy fix, would you want to do any type of discount on a swap with a new one?

OFA normally gives a 90 day warranty on their remotes, but I'm normally way more generous than that. However, I think you'd agree that 2 years is 'out of warranty' by anyone's standards.

But, I'd be more than happy to help you try and get it working again. If you can verify whether the '3' and INFO buttons still work, that will confirm or deny John's theory. In the event that they do not work, the chances are very good that you have a break in one of the traces on the PCB somewhere. Given that we know which line is broken, we can help narrow down where you would need to look on the PCB. If you find the break, fixing it will probably be as simple as putting a little conductive paint over the crack. If you don't have any conductive paint, you could try adding a little solder over the crack. If we get to that point, we'll figure out what tools you have in your arsenal and we'll find the best one.

[johnsfine]

Are there any good photos of an 8910/9910 PCB floating around any of our file areas?

I don't feel like opening my own 8910 at the moment to get a look. But with a look at a good photo, I should be able to tell you where to look for the broken trace.

Also, I guess it isn't really as unlikely as I first thought to have some of the 8 broken and others not. Previous cases of problems with such traces have been nearer the mpu than the keyboard, so all 8 are affected together. But the trace could be broken between keys. If one or both of those other keys do work, we can tell from that photo I was hoping for whether that is plausable and if so it would narrow down the exact position of the break.

[The Robman]

Use this link to get to the FCC page for the URC-9910:
https://www.hifi-remote.com/forums/dload ... le_id=3221

There you can find a PDF file with internal photos of the remote. There is a picture of the button side of the PCB but it's not very hi-res, so I don't know if it's good enough.

If that pic doesn't work, I'll take a pic myself and post it.

[johnsfine]

That sure is hard to see.

On page 8 of that you see S26 (which I'm pretty sure is the '3' key). There is a trace from there to a hole near S25 and from the hole to S25. If the 3 key works and the '2' key doesn't, that has to be the bad trace.

But notice that half of S26 also connects to a trace that runs up the edge of the board to the info key (S22 on page 7). But those edge traces are to blurred to be sure which is which. I can't tell which side of Info it hits, so I can't begin to guess which of the several holes has the route on the other side of the board over to SAT, CBL, and Menu. If they are routed from Info, then it can't be correct that '3' and Info work while the others fail.

I think the only way '3' and Info could work and the others fail is if:
1) The hole between S25 and S31 is the route (on the other side of the board) to the MPU.
2) The hole between S24 and the edhe of the board is the route to Enter, SAT CBL and Menu (which doesn't seem likely)
3) The break is between the hole mentioned in (1) and S25. Probably right at the hole.

[gpeck]

The Info & 3 both do work. I will take a closer look at the PCB where John says to look. Now I just need to find some conductive paint. Wonder if Radio Shack has it? It has been a long time since I did any soldering (Heathkit was still around), so I'd prefer not to try and solder.

Rob:
Sorry, I did not mean that you should replace it because I bought it from you. I wasn't sure if you did any refurbs. I just that if you did do refurbs maybe you would give me a few bucks of a new one if I sent you in the one that I am having problems with.

Thanks for the tips! I'll let you know what I find.

[kupakai]

Radio Shack has it. It's called Circuitwriter Pen and works great. I've used it to fix traces on keyboards. It would be much easier if you had a continuity checker like a multimeter, though.

[gpeck]

I just broke out my ol' BK Precision multimeter. Thought I would try to ohm things out. But, I am having a bit of a problem trying to figure out the PCB. A schematic would be nice. But, I haven't found any for the board itself.

[gpeck]

After ohming things out, I found the break right where John said it would be, "The hole between S25 and S31 ". After cleaning up my sloppy solder the remote is working like a champ again. The Radio Shack by me did not have the Circuiwriter pen. With out your guys help I never would have found the break.

Thanks all! I really appreciate the help.

[The Robman]

That's what this group is all about! Well done.

[Ube_Astard]

Is that FCC file still available? I have tried the link and am getting error message.
My up/down/left/right, select and exit buttons have stopped working and even though I have opened up and cleaned the contacts and that, I cant resolve it yet.

[The Robman]

I just found the original file via Google search and restored it to the link above

[Ube_Astard]

Thanks Rob. Theres only one page on the link BTW but I will try a search myself.

Regards

[The Robman]

Sorry, I didn't notice that it was only 1 page. Here's the link that I found by searching for FCC and DI29910

http://fccid.net/document.php?id=265040#axzz3HCadOhe1