Icom R2500 question

[wcu02mpa]

I have a recently acquired R2500 with the control head. Do these use a regular 6-pin RJ12 pass through cable? I.e. any crossover pins? I found one old post somewhere that said it was a pass through, but want to confirm that. I am using an aftermarket power source and the radio body switch lights up but the control head will not power on; Voltage showing 12.33V. Both radio and control head are like new. The RJ12 cable is brand new.

 

[kruser]

My R2500 radio to control head RJ12 cable is straight thru wiring. Lay the connectors from each end side by side and the wire colors all match on both ends.
Make sure someone didn't expose the RJ45 jack on the right side end of the control head as it can't be used for the control head even though an RJ12 plug will plug in. Only the RJ12 jack on the left side of the control head will work.
I never figured out if the RJ45 jack has any useful signals on any of its 8 pins. The RJ45 jack should be plugged with a nice fitting flush rubber plug if it's never been tampered with.
I'm pretty sure you should be able to find a PDF service manual with very readable schematics online. The manual for the 1500 will also show the control head wiring and should list the signals and voltages that should be present on the six wires in the RJ12 jack. The cable and signalling are the same between the R1500 and R2500 so either service manual should give you info to troubleshoot at least the control head wiring.
Icom still had stock of the complete control head for the 2500 maybe a year ago. I think the parts guy told me he showed over 100 of them still in stock. They were also pretty cheap. I think I paid maybe 40 dollars for a new 2500 control head. The white colored rubber keys had all turned dark on my original 2500 control head making them impossible to read which is what prompted me to check with Icom and see if they had just the rubber keys. Nope they did not but then he told me they did have the entire control head!
I don't recall the part number but if your voltages on the RJ12 cable check out good coming from the main chassis, you may want to check with Icom and see if they still have any more 2500 control heads.
I recall when I first plugged in my replacement control head, I figured I'd need to write all the memory info back into the control head but I found out that data is stored on a chip in the main chassis and not on a chip in the control head. So swapping the old with the new was basically just plugging the new head in and I was back in business immediately.

 

[Ubbe]

I had that problem with my 2500, and also a fellow 2500 owner, and I measured that the on-off signal came to the correct IC in the main unit but for me it seemed to be some kind of short circuit and the power supply in the main unit would not start due to the large current needed. I took aout all modules and inspected and resolder as much as possible but didn't help. It somehow repaired itself after 2-3 months but the BFO circuit no longer worked. Perhaps there was a short somewhere in that area and the component finally failed and released the short circuit.

You should always be able to remote control it through USB using the Icom application. If that works then the control panel are faulty.

/Ubbe