The red light on your disk drive is not promising I think, but you should be able to get some output to the terminal before it tries to talk to the disk. You should have the terminal turned on before you power on the SPU. In the video it looks like the latch mechanism on the terminal power button may be broken as the button pops right back out and the terminal does not appear to power on. If you hold the power button on the terminal down does the display come up with function key labels on screen etc.? If so, try turning the SPU key on while the terminal is on (self test may take a little while, but it has been several decades since I turned on a 37 so I don't recall exactly). You can watch Lee Courtney's Series 37XE power up video on YouTube which might be helpful. https://www.youtube.com/watch?v=DGtEvZRMPIk On Thu, Sep 2, 2021 at 6:26 AM Iban Cardona via cctalk <cctalk at classiccmp.org> wrote: > > Hi, > > some weeks ago I've purchased a System 37 in ebay. This unit was ebay in > the year 2020 and the owner was made this video too: > https://www.youtube.com/watch?v=F1CZKQtaoSo > > When I power up the displays shows a 1. Sometimes if I stop and start fast > the display shows a 2, but in all the cases all the leds stills lighted. > > The voltages on the power supply are OK, and in general I the unit have a > good look, I don't see corrosion or leakages from capacitors. > > Looking the SPU training PDF of Bitsavers/HPMuseum , looks that maybe is > related with a ROM or the WCS. > > Somebody have more info about this error, or know if is possible get some > schematics / service manual? > > Thanks a lot > > Iban