JP1 Remotes

EChas3 · Joined: 10 Jan 2010 Posts: 13

If I still get a BAD E2 on a MFR RESET on a URC-8910B02 after removing the batteries, shorting the power leads and loading new batteries, is my memory shot?

Any ideas welcome.

The Robman

EChas3 · Joined: 10 Jan 2010 Posts: 13

Thanks Rob, but I think I was doing it correctly for a 8910. (Hold set until menu displayed, Record key, Select & Select. Still get BAD E2.)

I saw another post (not yours?) suggesting other extreme measures like pulling batteries for a day or touching leads together to drain any caps.

I'm at a loss unless there are any tricks left. I suppose I haven't tried loading a reset file from IR with the batteries out. (As I was hunting for ideas I learned that with the simple parallel interface cable batteries aren't needed. I suppose I can try the three batteries trick, too.

The Robman · Posted: Mon Jan 11, 2010 11:19 pm Post subject:

Maybe, like the message, you just have a bad EEPROM chip. Might be time to get your hands dirty and try replacing it.
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EChas3 · Joined: 10 Jan 2010 Posts: 13

Where can I get the right EEPROM? I'm not afraid to take it apart.

I was planning on adding a pin block to my URC-7800B00, anyway. Ordering one pin block from Digikey didn't seem worth the shipping. Smile

The Robman · Posted: Sat Jan 23, 2010 12:04 pm Post subject:

I think Digikey has a $25 order minimum, people usually use Mouser for small orders. I have loads of EEPROMs and 6-pins left from my remote mod days, so I could give you 2 of each for $10 shipped, if you want.
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EChas3 · Joined: 10 Jan 2010 Posts: 13

I pulled out the two screws in the battery compartment and the remote body resists my attempts to seperate it. I'd bet it's built with 'catches' along the side and the correct squeeze will free it.

Anybody know the right squeeze?

The Robman · Posted: Sun Jan 24, 2010 2:44 pm Post subject:

Read this...
http://www.hifi-remote.com/jp1/disassemble/
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3FG · Expert Joined: 19 May 2009 Posts: 3367

Also, the instructions for opening the 6131 give a similar approach but with somewhat different pictures.
http://www.hifi-remote.com/forums/dload.php?action=file&file_id=2461

EChas3 · Joined: 10 Jan 2010 Posts: 13

Thanks to a little direction posted above, my 8910 is in pieces; but I've got one extra. There's a 1-inch coil that fell out. Phone upgrade receptor perhaps? There is some very thin wire hanging from the coil that probably short-circuited something causing my problem.

On the chance that it was temporary, I put it together 75%, provided power and tried a reset. Still no joy. Do I need to re-install that coil?

After seeing the size of the chips, I realize a soldering pen may be in my future. Suggestions/guideance is welcome.

The Robman · Posted: Tue Jan 26, 2010 10:12 am Post subject:

The coil is indeed for phone modem upgrades. If you want to re-attach it, look for two small solder spots in the circle on the PCB, the two wires hanging from the coil go here. To re-attach, position the coil on the circle, solder the wires to the two solder spots (it doesn't matter which wire goes to which spot), then use hot-glue to hold the coil onto the PCB.

If you know that you'll never need it, you can leave the coil off, it's not needed for remote operation.

To remove the EEPROM, I would recommend using a knife to cut the 8 legs of the chip, then remove the chip and then use desoldering braid to remove the legs. There's no point in trying to save the EEPROM if you have a replacement already, and trying to save it could result in damaging the PCB.
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EChas3 · Joined: 10 Jan 2010 Posts: 13

OK... Now I'm trying to ID the EEPROM in my URC-8910. Looking at the chips I got in the mail, I see ATMLH704 - 16B 1 - PGH7083A (I found a magnafying glass!)

In the remote, U5 (HT1381 - 152G0241) & U2 (A51So - CH18) are obvious. I would have expected to see some chip with a similar number. Is the chip I want to replace on the key-contact side of the board?

Is there a good reason not to simply cut out the old EEPROM and solder the replacement to the legs of the old one?

Sorry I'm such a tyro, it's been a long time since I messed with integrated circuit boards. The components seem 1/4 the size of my memory.

I welcome all input.

The Robman · Posted: Wed Feb 03, 2010 11:40 pm Post subject:

The EEPROM chips is close to the main MCU processor. The processor is under a circular black glob. The EEPROM is a tiny chip with 4 legs on each of 2 sides, and it's PCB spot is labeled E2. It's a surface mount chip, it's not a DIP part with punch-thru legs.

If you have carefully cut the legs of the old part and removed it from the board (and I say "carefully" because you need to make sure that you don't cut any traces on the board), you can remove the old legs one at a time using the soldering iron and some de-soldering braid. Once the old legs are off, the new EEPROM will sit smoothly in the vacant spot.

Before soldering the new part in, I would recommend adding a little flux to the 8 pads. Be sure to put the new part in the right way around, pin1 of the chip is usually marked with a dimple or a spot.
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EChas3 · Joined: 10 Jan 2010 Posts: 13

Thank you Robman but my remote doesn't appear to have a E2 PCB spot. Near the IR emitter, there's one black blob and a chip with 14 or 16 legs (obviously not what I'm looking for.)

The only other two chips I find are those I mentioned above. They are near another black blob at the opposite end from the IR emitter. Not to be critical (you're likely doing this from memory) but could I want the chip near the PCB spot U2? That chip is printed with "A51S0 - CH18".

Is it normal for chips with widely different numbers to be compatible EEPROM's?

Thank you for all your help.

The Robman · Posted: Fri Feb 05, 2010 8:42 am Post subject:

I guess I'm gonna have to crack open a URC-8910 and see exactly how things are labeled and post pics.
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