Batboard

I have a surplus XTL5000 M20URS9PW1AN purchased headless off of the usual dubious online source.

I put a W5 head on it but get FAIL 01/90 and it power cycles and repeats. I had doubts about the condition of the flex, so picked up a O5 head with flex, but still get the same FL 1-90 and power cycling. I'm not intimately familiar with XTLs - I have power connected plus a HKN6161A data cable (which I've read can also be used for programming) connected to the rear accessory connector along with ignitiion sense and the emergency switch pins shorted.

If it was just the O5 I believe you can get a 1-90 for a firmware mismatch with the head, but saw the same error on the W5. Unfortunately I don't have any another ASpectra or XTL that has the right parts to interface with a W5 to double check the head - and I don't have a cable to deal with O5 head firmware.

Am I missing anything obvious or do I have a dead unit? Internal fuse maybe? Is there any way to try to read it without a head?

Brick should turn on when powered and emergency jumper is present unless set for ignition sense. Control head type sounds like it is wrong. Selecting the wrong CH can result in Fail 01/90 and power cycle. Confirm the head selection is correct. Then we troubleshoot some more.

So what you're saying is that if it was set up for a W9 but I have a W5 or O5 on it then the normal response would be 01/90?

And you're saying it should be able to be programmed without a head as long as power is connected? I thought I read otherwise that you had to have a head on it to program since that was what controlled power on. I will try.

I tried what I think your suggestion was and applied power headless and tried to read with CPS but get 'Radio Failed to Acknowledge Error Context: 24, Status: c0000386'. Which was about what I expected.

Wouldn't I at least need to emulate the power on switch of a head?

Depends if the control head for power up is checked. I think the W9 may require the head to be present as well. O5 doesn't.