Checked out my 53310A a bit today. It's a little dirty and there's some burn-in on the CRT, but still looks good. Man it's bigger than I was expecting. Much wider than my 8560E, but fortunately not as long.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=910082;image)
The listing showed that it was failing the trigger light test for the A2 board. Sure enough, it did that when I ran the self-test. Checking the DAC parameters, the offset looked like it was at default values, so I let it measure and set new offset values and bingo! All tests pass now.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=910078;image)
After taking these photos, I noticed that the first pic shows "ref error" in the bottom-right status area. It was the first time I saw it. Normally, it says "ref int" and when I turned it on and off a few times, the error didn't return. Upon leaving it for a while, it shows "ref error" again at first power on and eventually switched to "ref int". So, it seems that it needs a little time to lock onto the internal clock reference.