Standby button doesn't work

Posted by: Bagpuss

Standby button doesn't work - 19/10/2005 21:23

Hi All,

Just picked up my Central, and noticed that the standby button on the front panel doesn't work. If I use the remote, then I can put the unit into standby.

I'm running the 1.10 rc1 software.

I've opened the Central, and examined the PCB containing the buttons and all appears to be in order. I've tested the buttons with my multimeter, and they all work (even the standby one). I've also traced the standby connection to the connector and through the cable. It all looks good.

Does anyone know what other possible issues might cause this failure to go into standby when the button is pressed.

Thanks,

Andy.
Posted by: The Central Guy

Re: Standby button doesn't work - 19/10/2005 22:52

Hi Andy,
I've never seen that one with my collection of Centrals. It sounds like you've looked at the things I would check out.

Since the remote pause button is working, it does seem that there might be a problem with your button in some way. But you've checked that...Hmm...I'm at a loss right now, let's see if anyone else has any other ideas....

Thanks, Randy
Posted by: tfabris

Re: Standby button doesn't work - 20/10/2005 00:57

My prototype Central developed a problem where certain buttons on its front panel would not work. The Standby button was not one of them, it always worked. Unfortunately, the panel assemblies were different between the prototype and the production modules, so I couldn't get a replacement. I now have, thanks to Mike Schrag, a whole replacement Beta test central with a working front panel.

But anyway, here's the deal with the prototype. I got the schematic for the front panel assembly directly from Hugo, and traced every connection and tested everything with a multimeter. I could find no fault in any connection, yet certain front-panel buttons just. would. not. work.

Oddly, this was accompanied by a reduction in responsiveness to the remote control. I don't know if that was related or not.

I never got to the bottom of what the problem was.

So... I don't know how to solve your problem, but I just wanted to say, it might not be a broken wire or a loose connection. It might be something harder to trace.
Posted by: Bagpuss

Re: Standby button doesn't work - 20/10/2005 11:33

I've done some more research on this, and it appears that the standby button is in the permanently pressed state. This could perhaps explain why the Central is behaving strangely.

Could someone with a working standby button test something for me.

Disconnect the LCD support board (bolted to the back of the LCD) from the main board.

With your multimeter, check for continuity across the various buttons on the button board. You will probably need to remove it from the front panel to do this.

If you are looking at the buttons with the silkscreened writing the right way up, check as follows:
1 2
o o
XX
o o
3 4

The little circles represent the pads attaching the button to the board.

On my Central, pads 1 and 3, and 2 and 4 on all buttons are connected together (not unsurprisingly, when you look at the buttons).

1 and 2, and 3 and 4 are open circuit until you press the button.

With the button board connected to the LCD support board, 1 and 2, and 3 and 4 are open circuit for all buttons except standby. This doesn't seem right to me.

I'd really appreciate it if someone would check their Central to see if their standby button is open circuit across these pins, or closed circuit. My suspicion is that a 'normal' Central will be open circuit.

Cheers,

Andy.
Posted by: Bagpuss

Re: Standby button doesn't work - 20/10/2005 17:00

Just had a thought.

If I go to the shell prompt, is there any way to read the front panel button presses?

I guess I could then verify what's going on with the standby button.

Does anyone know how to do this?

Thanks,

Andy.
Posted by: tfabris

Re: Standby button doesn't work - 20/10/2005 17:15

I dunno, it's starting to sound like you've traced it to a hardware problem with the button and the shell prompt isn't going to be needed.
Posted by: Bagpuss

Re: Standby button doesn't work - 20/10/2005 17:29

Hi Tony,

Actually, I don't think it is a hardware problem with the button.

I've swapped the now playing button with the standby button, and the now playing button still works, but the standby one is still broken.

It doesn't therefore appear to be a mechanical issue with the button itself, but a electronic problem somewhere on either the button board (unlikely, given the low component count) or the LCD board.

The standby button works fine when the button board is tested in isolation, but not when it's connected to the LCD board. Weird!

Andy.
Posted by: The Central Guy

Re: Standby button doesn't work - 20/10/2005 18:53

Just a question...Is this the Central that was sold on eBay recently? Didn't that seller say something about the display being replaced or refurbished? I was wondering if that repair might have had something to do with the problem you're seeing? Maybe a secondary symptom or something?

Thanks, just curious.....Randy
Posted by: Bagpuss

Re: Standby button doesn't work - 20/10/2005 19:06

Hi Randy,

You're right. This is the same Central that was on ebay.

It turns out that the seller used to work for Rio in Cambridge. The replacement of the LCD was done using parts lying around in the empeg/Rio/DNNA/Sigmatel offices.

I am talking to the seller about this, so hopefully we will be able to play swap the parts with some of the other Centrals still in the office until we fix this. In the meantime, I'm trying to find out as much as I can about the problem, to try and minimise the time it takes to resolve.

Andy.
Posted by: Bagpuss

Re: Standby button doesn't work - 22/10/2005 16:54

Just in case anyone is interested, the surface mount buttons used on the Central can be source from Farnell in the UK.

The part can be found here:

Rio Central surface mount buttons

I've checked the measurements from the spec. sheet, and they are identical to those used on the button board.

Just in case you ever need to replace one, as I've just done (it didn't make any difference, though).

Andy.