mcgee@nic.csu.net (03/27/91)
Last night was the primary application of power (Read: Smoke Test) for my PDP 11/44. Everything spun up, the room lights stayed lit, and, so far, no one complained about the noise the fans made. However, I have a problem. The diagnostic rom says "?22 CP HUNG" and a T/E trace says "CONSOLE -A7". Does anyone have any guess as to where I should start looking? -Rich
terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr.) (03/27/91)
In article <1991Mar26.084525.459@nic.csu.net>, mcgee@nic.csu.net writes: > Last night was the primary application of power (Read: Smoke Test) > for my PDP 11/44. Everything spun up, the room lights stayed lit, > and, so far, no one complained about the noise the fans made. > However, I have a problem. The diagnostic rom says "?22 CP HUNG" > and a T/E trace says "CONSOLE -A7". Well, you have an old '44. The newer ones emit more useful error messages. The CP (CPU) errors mean that the console processor (8085) couldn't get a proper response out of the main CPU. Possibly a missing board, mis-seated board, or no memory at location 0. Also, a failure to start can be caused by missing bus grant continuity or a missing 9302 terminator module. I sug- gest you send direct mail to me and we can set up a time for a phone call when you're at your 11/44. Terry Kennedy Operations Manager, Academic Computing terry@spcvxa.bitnet St. Peter's College, US terry@spcvxa.spc.edu (201) 915-9381
cosheff@netmbx.UUCP (Charles Shefflette) (03/28/91)
mcgee@nic.csu.net writes: >Last night was the primary application of power (Read: Smoke Test) >for my PDP 11/44. Everything spun up, the room lights stayed lit, >and, so far, no one complained about the noise the fans made. >However, I have a problem. The diagnostic rom says "?22 CP HUNG" >and a T/E trace says "CONSOLE -A7". Having just fixed one which had a similar symptom, and not knowing your exact machine configuration, try the following. 1. Remove the bus jumper from the CPU backplane to the rest of the machine. Replace it with a terminator. 2. Power the machine up. If you receive a console emulator prompt the CPU is ok. If not, you now need to start looking at things on the CPU backplane. (see below) 3. If step 2 passed, reinsert the unibus jumper between the CPU and the rest of the system. If you have more than one expansion backplane, remove the jumper to it, replacing it with a terminator as above. 4. Continue steps 2, 3 until the CPU again gives a ?22 CP HUNG message. At this point you have located the backplane where the problem lies. 5. Now that you have isolated the defective backplane, you are down to just a few potentially failed boards. It is now trial and error to locate which one is hanging the bus. Do this by removing each board individually, placing a bus grant card in position D of the card slot, and cycling the power again. You have to be careful, though. If the board uses NPR signals, you have to also either jumper pins CA1, CB1 or use a G7227 grant board instead of a G727. (I would recommend this one in any case just to be sure.) You need to be careful of such things as RH11 controllers and so on, you can't pull the boards in them like that, you have to be a bit more careful of what you pull and replace with one of them or other things such as DV11s... In any case, the above procedure should at some time result in the CPU finishing its power up test and giving you a normal console prompt. When it does, you have located the defective card. Now prepare yourself for the agony of the replacement cost. Once you have found the potentially failed board, carefully inspect the back- plane on the wiring side to ensure that if the board is not an NPR board, there is a jumper installed on CA1 -> CB1. If not, put one there, replace the board and try it again. If all of the above steps result in you standing there holding a board which is indicated to be bad, replace it with a new or repaired one. If the above procedure fails, send me an e-mail with some more specific information about your system and I'll try to give you a bit more information. I'm quoting the above from memory - I'm at home and all my 11/44 references are at work! >Does anyone have any guess as to where I should start looking? >-Rich Hope this helps. Chuck