wrote in message
...
Anyone know if there is a solution to low display brightness on a HP
54111D oscilloscope, like maybe power supply capacitor replacement?

The CRT power supply voltage described in the service manual is
puzzlingly-low...only 120 VDC (?!?) The 300V switching supply is described
as used for generating the 5V logic supply.

I haven't dug further, but wonder how a color CRT can get by with such a
low voltage...or if the CRT module has an integral flyback supply for
anode voltage, and repair being module-focused, isn't discussed.

The CRT thought led me to wondering if CRT rejuvenation was an option.

Thanks

Murray

Hi Murray,

Do you have the CLIP for the 54111D available? Can you get hold of an ESR
tester? And where abouts are you located - 120 or 240 volt land?

You might go on the HP Yahoo group with the same request.

https://groups.yahoo.com/neo/groups/...equipment/info

It does sound like one of the bulk capacitors has failed if the 300 volts is
that low.

You must get the power supply working first before any other diagnostics are
done.