Replacing batteries in my Allen ADC 3500

[Vebo]

I just replaced the batteries in my Allen ADC 3500. The AV card retains it's memory via a 3.6v rechargeable battery pack - mine was in-field retrofitted so that the batteries are off the card in a separate box in case of leakage.

The combination action memory is powered by a 2.4v rechargeable battery pack. While this battery pack is mounted on printed circuit board, they are in such a place that if they leaked, it would most likely drip to the bottom of the organ and not muck up anything much. At some point I may find another box to mount them in like the battery pack for the AV, but as I just replaced the pack, I'm not worried about leakage right now.

Both battery packs are replacements made for portable phones, and they were readily available on the internet (probably also at any local electronics or general merchandise store that sells portable phones). I just snipped off the connector on the new battery pack and soldered a splice in with the existing connections on the organ. It was a snap, took me about 40 minutes to do both.

The batteries only charge when the organ is on, so I left it on overnight to get a good charge, and will turn on again later today so that I know they got a good 24 hour charge to get them started.

All settings were lost during the change-out, so all the combinations were blanked. It was no big deal to me, but if it's an issue for you, you may want to jot down your combinations. One person commented that they had changed the batteries out while the organ was on, thereby retaining his settings. But working on any electronics while they are plugged in an/or turned on could be dangerous to you and the instrument, so it is not recommended.

This information is available in at least one other thread, but it took me some digging to find it, so I thought I'd summarize it here.

[Vebo]

These are pictures before the replacements.

[myorgan]

Nice work!

When it comes time to replace the cover of the cage, if the wires for the AV-1 battery are in the way, note the small gap between the side and bottom border of the cage just under the power supply.

Of all the Allen ADC organs I've seen, this is the first I've ever seen with the power supply on the right-hand side of the cage. Is that common for theatre organs? Just curious.

Michael

[Vebo]

The official Allen repair/remediation involves a new cage cover that has a gap for the new wires coming out of the card cage. Seems like another opportunity to charge for another part.

Yes, I noticed the gap on the lower right, but the wires did not readily slip in, so I opted to leave the “rumple” in the fit of the cover, rather than risking damaging the insulating cover of the wires. I mean, what's the risk of a less than flush fit of the card cage cover?

I have no idea about the power supply placement in the card cage. It is in keeping with the docs I have for this model.

[myorgan]

I have no idea about the power supply placement in the card cage. It is in keeping with the docs I have for this model.

My documentation says the same thing-I have just never seen it before, and was musing in writing.

I think the cage cover is there for EMP protection, but it has a fair number of holes for ventilation, so I don't think a rumple in the cover will matter a bit. I think perhaps it is sealed to prevent insects getting into the cage. Either way, your battery issue is resolved.

Michael

[AllenAnalog]

Here's a thread I started when I found one of those Allen battery retrofit kits on ebay:

https://organforum.com/forums/forum/...t-from-factory