Booting Issue

replace the Acquisition Power Distribution Board on back wall next to umb

Sorry, forgot to mention in my initial post, the APDB has been replaced too, the issue remains unsolved. I am just running out of ideas!

Unfortunately every time I ever had the issue it was the Acquisition Power Supply, are you a 100% the Acquisition Power Supply you got in and replaced was a good one. I will look at the wiring diagrams and see what I can figure out but if you get it fixed please let us know. Maybe give david a call at aue, he knows those machines really well

Well, I tried the APS on a working system and it is good and boots all the way.

I have had similar issues and its been the power supply voltages being out of spec. I know you mentioned you place them but I would double check your voltages are good coming out of the power supplies. Also check conections I have had connectors get burnt pins causing voltage drops.  If the power supply voltages are good you may be able to check voltages at APDB. You may have bad wiring or connection causing a voltage drop.

We actually purchased the whole assembly for the APS, PPS, and APDB and tried it on a working system and it's good and boots normally, but same does not work on the dead system

Hello

The system shuts down after 4 seconds, the AC relay in the AC tray power supply does not latch. how is it possible we measure the voltages on the APDB?

Thank you

Check the cable going from the power supply to the AFP (front card cage cover). I've seen those pins burn out and cause issues.

Thanks Dany,

I actually disconnected all the cables from the power supply assembly to the front end front plane board so to isolate the issue, but still no luck yet. We also replaced the BTM board today and still no progress, very interesting!

Was a solution ever found to this? I have an iU22 with the exact same issues