JP1 Remotes

[ElizabethD]

Before the remote broke yesterday morning, I was able to see the display at all times and test new uploads immediately while the 8910 was plugged into the PC. Now, out of the blue, I can’t.

I can’t think of a cause. The only activity before the trouble was Low battery indicator and, therefore, battery change.

With the dead display I was able to use IR(v402)-I added a macro and uploaded it. Also did several trial transfers from KM(820) to IR and uploaded to remote. The odd thing is that the display stays frozen and I can do nothing until I unplug it from the PC. At that point the display looks like one after a reset or upgrade (all display elements are on) for several seconds and then it unlocked, collects its thoughts and functions perfectly well.

Trying to figure out what’s going on, I did several things, none of which helped: reboot the PC with/without 8910 connnected, total ops reset (display said it cleared RAM and E2), revert to older IR file from several weeks back, revert to older RDFs (1.14 and 1.15), change batteries again. After all this experimenting, I discovered that just plugging in the jp1 cable causes the “freeze”. Computer connection and IR use seem irrelevant.

Since the remote works and since downloads and uploads actually work this is not a tragedy, but sure is incovenient. How can I recover from this mess and what broke it?

[Nils_Ekberg]

This is just a guess but I think the battery issue may just be a coincidence and not have anything to do with the problem. Anyway, try it without the batteries and see what happens.

Since it resets the minute the cable is connected it almost sounds like something in the cable got messed up. Could be a bent pin or a pinched/shorted wire. Check the connections at both ends of the cable to make sure the connections are good and not touching each other and that no pins are bent.

Curious, if the remote is in reset state until you unplug the cable see if pressing any button clears it before it normally clears itself.
_________________
Nils
Files Section
Diagnosis File Section

[ElizabethD]

Nils, thanks ... need some clarifications on your answers
1. "...try it without the batteries and see what happens." - you mean just take out batteries, plug it in and report what I see?
2. "Could be a bent pin or a pinched/shorted wire. Check the connections ..." - I looked at the pins on the board, they look good. Cable looks sound - each wire goes through little holes - I'll take a meter to it tonight and check if things are crossconnected, but I doubt it since remote-IR conversations take place properly
3. "...if pressing any button clears it before it normally clears itself..." - no, definitely not. The only way any button clears it is few seconds after unplugged - yet, while it looks like a reset, it's not a reset.

[Nils_Ekberg]

Yes, I was just suggesting trying it without the batteries in the sequence you outlined.

Let us know what if anything you find when you put the meter on it.
_________________
Nils
Files Section
Diagnosis File Section

[ElizabethD]

Thanks again.
I’ll do the “no batteries” and cable check tonight. Btw, cable is not manufactured at home, should be good, but without opening the parallel side I have no idea what’s inside.

In the meantime, while looking to confirm pin numbers to look at, I just stumbled on this interesting theory in my collection of jp1 information. I have to leave the laptop at work tonight, so will try this “drop the voltage” trick tomorrow night. Anywhay, this is the info:

“9. PERMANENT RESET Sometimes a remote will remain permanently reset as long as it is connected to the interface. The symptoms of this are: (1) You can't operate the remote while it is connected. (2) The remote's red LED doesn't blink twice following Check Interface, Upload, or Download. (3) The red LED blinks twice whenever the remote is disconnected. There are two causes for this problem. One is the voltage mis-match situation discussed previously. If you are working with a 6-volt remote with fresh batteries, and your PC's output voltage is not high enough to release the reset signal on the remote's processor, the processor will remain reset as long as the remote is connected. The important thing to remember is that this shortcoming does not prevent you from using the interface to upload or download because the processor must be held reset during those operations anyway. It simply means the JP1 connector must be unplugged before the remote can be operated, something most people do routinely.

The reduction of resistor R2 in this Rev 5 version of the interface should greatly reduce the incidence of permanent reset, but there is not enough evidence yet to confirm this, particularly when used with laptop PC's. If you absolutely must be able to operate the remote while it is still connected to the interface you can try reducing the operating voltage of a 4-cell remote to 4.5 volts by replacing one cell with a dead battery or a dummy. This will result in some reduction in maximum operating distance, so it may not be a totally satisfactory solution. You can make a dummy AAA size battery by cutting a 1-3/4 inch length of 3/8 inch diameter wooden dowel rod and wrapping it with aluminum foil or aluminum (not cloth) duct tape.”

Quote is from Simple Interface Rev 5 by Tommy N. Tyler 26 November 2002. I probably got it from yahoo, don’t recall.

This is getting interesting.

[ElizabethD]

Nils, Per your suggestions,
1. I did continuity check on the cable and checked that roughly 30 or so combinations don’t cross wires. Not very scientific, but really the cable looks good. I don’t think IR would work well as it does if the cable was bad.
2. “Take out the batteries” experiment actually got a bit complicated and I doubt you need to read all the details. Basically when you remove batteries everything is dead. When connect to PC different things happen partly depending on the state of PC.

Scope creep is a problem in such experiments: is PC on or off, is 8910 connected when PC is on, when do we connect, when disconnect? I played with some scenarios and my general conclusion at this point is that my 8910’s Low Battery indicator might be triggered bit too early. Further, under the “drop the voltage” theory, I restored 8910’s normal behavior with two old batteries rescued from the trash, HURRAY! Replacing one battery was not sufficient.

Also, this time, with all new batteries, 8910 got completely reset to factory state when I plugged it into a PC which was powered up – this did not happen before.

So what have I learned so far ?

[Nils_Ekberg]

It sounds like you hit the typical problem with the voltage in the remote being higher than the interface which causes the remote to reset. I ran into the same problem with a 2116 with new batteries, simple interface, and a laptop. My only cure was to use an ultra interface which solves the voltage problem.

Are you using a simple or ultra interface cable?
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Nils
Files Section
Diagnosis File Section

[ElizabethD]

OK, interesting. Many thanks for sticking with me through this. Can I now quit the experiments?

Prey tell, what is "simple or ultra interface cable"? Got it from BooDo or something like that, no idea what kind. How can I tell?

[ElizabethD]

One more thing: so the laptop vs remote mismatch can occur even though the laptop is not running on batteries but is hooked to 115-127 volts of real power?
_________________
Liz
Tweeking 8910, HTPro/9811, C7-7800, 6131o, 6131n, AtlasOCAP-1056B01, RCA-RCRP05B and enjoying the ride

[The Robman]

[ElizabethD]

What would I do without help from this group?!
When I first got this remote I searched google about what the 6 pins inside where all about ... stumbled upon BlueDo and the rest you know.
My options are
1. Do nothing, I understand what's going on, workaround it
2. Fix the cable I have (how? resistors? where?)
3. Trash this one, get a new one. I just searched this site and didn't find a clear reference. Rob, I gather you make/sell cables? Do you have the kind I need?
_________________
Liz
Tweeking 8910, HTPro/9811, C7-7800, 6131o, 6131n, AtlasOCAP-1056B01, RCA-RCRP05B and enjoying the ride