I have an IBM 5161 that I got from computer reset a while back but, up until now, I was unable to test it because I didn't have an extender card. I have since soldered together a replica extender card and I'm trying to get everything working. When I first connected everything, I got an 1801 error on screen which, according to -0 could be caused by a lot of different issues. I did, however, notice that my pair of Seagate ST-251-1 drives which I'd mounted in the 5161 didn't spin up and make their unique startup noises. I tried two different cables and 2 different receiver cards but still got an 1801 error on screen. I then decided to swap out the backplane because I happened to have a spare. After replacing the backplane, when I switched the 5161 on, the ST-251-1 drives spun to life and made their unique noises. However, a couple seconds after that capacitor C4 gave me the magic smoke. Not having a spare capacitor and reasoning that there was something wrong with the original backplane, I transplanted the C4 capacitor from the original backplane to the replacement backplane. When I switched the 5161 back on, the ST-251-1 drives spun to life just as before but then, exactly like last time, the C4 capacitor blew all over again. At this point, I don't know if there's something wrong that's blowing that capacitor or if I was just unlucky and transplanted a dead cap. If I'm just unlucky, I could steal C2 or C3 from the original backplane as well because they have the same value(106 +16k - There are horizontal lines both above and below the "K") but I don't want to do that if there's something else wrong which could blow them too.
Any advise, insights, or diagnostic procedures would be greatly appreciated.
Any advise, insights, or diagnostic procedures would be greatly appreciated.
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