05-05-2013, 11:44 AM
A quick update.
If the Rectifiers arrive on Monday it will be a miracle, it being a Bank Holiday
Took off the back panel which was stuck with the leaked goo. Also had to disconnect the External Kathode connection and Fan. Fired it up just to check everything was as before. Got a wisp of smoke from a couple of big WW Resistors which live just below the Fan. They normally live in a howling gale, however it didn't seem to do any harm.
Eased off the Tube Base - Ceramic. All nice and clean but gave the sockets a brief spray of Switch Cleaner just to be sure.
Measured the two Resistors on the Base, R517 and R521 - both OK ish.
Measured the Resistor in series with the Brilliance Pot which is a bit high so is a candidate for change. It isn't on the Manual Diagram and I can't find MR502 and 503. In all honesty it hardly seems worth the trouble bearing in mind the high value Resistors in series.
Discovered the location of R501 of 502 - hidden under the edge of the top chassis. No designations though, unlike all the others.
Fired it up again and checked the PDA - down at 4.5 kv
While poking about discovered the reason for the low PDA and presumably the intermittant bright blob - dry joint on the V507 Anode. It's a wire loop through the PCB and a Ceramic Bead. I must have disturbed it while changing R515. Everything is desperately short but I managed to get the loop and Bead back through the PCB. However, while trying to reconnect the Anode Wire I broke it off, right by the glass of course. Insert Emoticons for swearing, throwing things and jumping about.
[OK:
- Joe]
So, it looks as though I'm doomed until Tuesday.
Alan
If the Rectifiers arrive on Monday it will be a miracle, it being a Bank Holiday
Took off the back panel which was stuck with the leaked goo. Also had to disconnect the External Kathode connection and Fan. Fired it up just to check everything was as before. Got a wisp of smoke from a couple of big WW Resistors which live just below the Fan. They normally live in a howling gale, however it didn't seem to do any harm.
Eased off the Tube Base - Ceramic. All nice and clean but gave the sockets a brief spray of Switch Cleaner just to be sure.
Measured the two Resistors on the Base, R517 and R521 - both OK ish.
Measured the Resistor in series with the Brilliance Pot which is a bit high so is a candidate for change. It isn't on the Manual Diagram and I can't find MR502 and 503. In all honesty it hardly seems worth the trouble bearing in mind the high value Resistors in series.
Discovered the location of R501 of 502 - hidden under the edge of the top chassis. No designations though, unlike all the others.
Fired it up again and checked the PDA - down at 4.5 kv
While poking about discovered the reason for the low PDA and presumably the intermittant bright blob - dry joint on the V507 Anode. It's a wire loop through the PCB and a Ceramic Bead. I must have disturbed it while changing R515. Everything is desperately short but I managed to get the loop and Bead back through the PCB. However, while trying to reconnect the Anode Wire I broke it off, right by the glass of course. Insert Emoticons for swearing, throwing things and jumping about.
[OK:
- Joe]So, it looks as though I'm doomed until Tuesday.
Alan
