On Tuesday, 2 January 2018 18:40:02 UTC, Murray atuptown wrote:
Thanks for the replies.

120 v ac

OK on thumbs down to rejuvenation...


I overly simplified the comments on the power supply which was evidently more confusing than accomplishing a summary.

Based on the service manuals description of how the voltages are produced, I offered two distractions. The overview described the +300 V supply as being used for producing the +5 VDC logic supply and the CRT supply as they name it is only +120 VDC. I didnt mean to sound like only measures 120 instead of 300.

There was an implied question-how the heck do they run a CRT on 120 VDC? I didnt (yet) see further explanation of internal functions on the CRT assy. I hope its an assembly with the ability to produce all support voltages for a CRT.

The diagnosis for CRT problems, as well as other modules, often ends with €˜replace the module...I get €˜why?, during the products heyday, but that leads to a €˜problem period (for wannabe users/restorers) in the future...which is now.

I havent measured anything yet...its usable, but Im just snooping around for answers for that day when all the room lights have to be off to see anything. If Im going to commit space to such a large (and loud!) Im trying to be proactive.

Ill read up on what I can measure without service accessories like extender board etc.

Thank you

There's all manner of reasons why it might be dim, including muck on the screen. Let us know when you've got some facts we can work with.


NT