Update on the
hp 5216A with toasted mains transformer.
Last weekend I had set it up for 110V operation, as half of the primary required for 230V is open-circuit, testing with a lamp limiter up to 100W and I only had about +60V on the +155V PSU output. Not much point in continuing, as I would need dig out the larger step-down transformer and the 5216A is only rated for 20W, the faulty transformer would probably go up in smoke.
![Lips Sealed :-X](https://www.eevblog.com/forum/Smileys/default/lipsrsealed.gif)
Yesterday I pulled the PSU board & set it up with external PSUs for each required supply. The 6237B was set for +5V on the main output for the logic, +6V/-6V for the analog supplies and the 711A was set for about +150V for the display supply.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1412203)
Everything was double checked before applying power and to my surprize the 5216A powered up OK and seemed to be counting.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1412209)
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1412221)
An oscillator was used to check the counting functions & the display drivers were 100% working.
![ThumbsUp :-+](https://www.eevblog.com/forum/Smileys/default/icon_smile_thumbsup.gif)
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1412227)
Only thing not working seemed to be the gate light, this was verified to be a dead lamp, by adding a new one in parallel, an easy fix compared with replacing the transformer.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1412233)
David