HP41 IR Printer Module

[ChanTran]

It's kind of strange that it works on port 2 but not port 1. The manual said that it has to be installed in the lowest number port and it worked in port 1 before. Executing commands don't cause nonexistant so it does recognize the module in port 1.
Anyone has any idea?

[cruff]

Does any module work in port 1? Perhaps there is an issue with the flexible conductors in port 1. Are they clean of dirt and corrosion?

[ChanTran]

Yes! Tried the Time Module there and it works fine.

[rprosperi]

Other suggestions:

I. Are there other modules installed? If so, remove them and try again.

II. Install new batteries. Of course this should not matter, but it sometimes does.

III. Clean the contacts of the module (very carefully!) and the contact areas of the port connector inside.

[ChanTran]

There were the Time Module in port 3 and X function in port 4. I removed them. Tested the IR module in all 4 ports only port 2 and 4 work. Ports 1 and 3 don't. The other modules work on any port.
I was about to try it on my CX blank nut but then the CX first report low battery problem with new batteries and then it won't turn on any more.

[PeterP]

Just throwing out some more ideas / thoughts here in case helpful:

Time, X-Func, and IR are all modules that relocate to Sub page 8 pages - 5, 3, 6 respectively. So maybe the relocation to page 6 is not possible from ports 1 and 3 due to some malfunctioning connection? (ie only odd pages work, not even?)

Do you have any application ROM with two pages available that you could try in all ports to see if that works?

[ChanTran]

No I don't have other modules besides those. I revived the 41CX Opt 001 (blank keyboard) and tested the IR module and it works with all 4 ports. I don't use the the 41CX because it has blank keyboard and being the halfnut the display is not as contrasty as the older 41CV.

[Diego Diaz]

Hi,

According to your description you more likely have a bad contact on the BAT line of the odd numbered ports.

Due to internal Flex-PCB layout, the lines for the even/odd interfaces are separated and connected thru the Keyboard PCB. So failures on one "side" (odd) may not affect the other (even).

Most modules don't use the BAT line, that's why you can use other modules on ports 1 & 3 without problems, but IR printer module feeds the IR diode from this line.

Hope this helps.

Best from Caribbean.

Diego.

[ChanTran]

That makes sense as the calculator doesn't say nonexistent when I execute function of the IR module, just no IR output. I know because I use an IR sensor to check with a scope.

[Jim Horn]

If it helps, an easy way to verify IR emitters like this (or TV remotes, etc.) is to look at them with a cell phone's camera. They respond to strong IR sources like that as if it was a blue/violet color and display it accordingly.