Main > Monitor/Video Forum
B&K 467 rejuvenator service information available
Ken Layton:
--- Quote from: Corey986 on May 12, 2019, 04:06:21 pm ---
I can't adjust R23 any lower than .2 on the meter so I'm hoping it's not supposed to be set to 0.
--- End quote ---
If that's the lowest it will go then you're fine.
Corey986:
--- Quote from: Ken Layton on May 16, 2019, 11:16:32 pm ---
--- Quote from: Corey986 on May 12, 2019, 04:06:21 pm ---
I can't adjust R23 any lower than .2 on the meter so I'm hoping it's not supposed to be set to 0.
--- End quote ---
If that's the lowest it will go then you're fine.
--- End quote ---
So just adjust it to the lowest the pot can go or should I set it to “tracking set”?
Thanks,
Cheers,
Corey
Sent from my iPhone using Tapatalk
philexile:
Hi Ken,
Hope you’re well! I’ve been messing around with the 467 and have a question. I was checking the heater voltages during Clean & Balance and Rejuvenation.
When Red or Green are pressed in Clean & Balance mode the heater voltage changes to 7.5vAC, but Blue is 8vAC.
When Red or Green are pressed in Rejuvenation mode the heater voltage changes to 15vAC, but Blue is over 17vAC.
I have had “better” results with blue guns, which requires me to push the red and green guns a second time — so I assume this wasn’t an intended feature of the unit’s design.
Do you have an idea of what I should check first?
Thank you!
Ken Layton:
I've never had a need to check heater voltage on the rejuvenator. I think you are worrying about nothing.
Remember, during the rejuvenation process (and clean/balance) the heater voltage is boosted to burn off contamination and improve emission.
Also, be very careful not to lift foil traces if you recap yours. The traces can lift/break if you are not careful.
philexile:
Hi Ken,
Thank you for getting back to me. I sent you a PM this morning, but I thought it might be best to also include an update in this thread. I went ahead and did a full recap of the unit, while also replacing some of the resistors.
Most of the capacitors had good ESR, but their capacitance seemed to have drifted up. For example a 1000uf cap read as 1318uf. Some of the higher wattage resistors had also drifted up. One of the three 620k 2 watt resistors in the center of the board read as 764k out of circuit.
I replaced all of the capacitors and the following resistors: R37, R38, R40, R41, R46, R47, R48, and R58. Unfortunately, now that I've completed the work on the unit, it doesn't work properly.
The most obvious symptom is the restore functions do not work — the unit doesn’t “charge up” when switched to that mode and when a restore button is pushed the ballasts do not light. I would "hear" the unit when it was switched to restore mode, but now it is mostly silent.
I’ve also noticed that the emissions readings are incorrectly and weak, even with a new tube. I confirmed this with a B&K 490 and Sencore CR7000. The 467 is putting out proper voltage however and I can set G1 and cutoff without any problems.
I think this has something to do with 270v, but I’m not sure where to begin. Would you be able to advise based on this information?
Thanks again!
PS – I didn't have any issues with the traces thankfully. This seems to be one of the "newer" units and 1974 is marked on the circuit board.