Yeah, the single turn was factory fitted for sure, I don't see any option markings to do with the 10 turn pot, but the same goes for the colour combinations for the binding posts. There must have been undocumented options available via the sales rep. or something.
I have same model. With both dials turned all the way down, and no load, the voltage display reads 32.2, current reads .07, and both CV and CC light illuminated. Any ideas what is wrong?
First check for leaking capacitors, these units are at that age and I've seen a few now that needed new caps and a good wash to remove leaked electrolyte. Then give it an adjustment as per the service manual and see if it comes good. I would also suggest checking the service updates for a few mods that will help improve the power supply too.
I'm not convinced that expensive caps are better or last longer than cheaper caps. I have some 3200 uf Nichicons that don't test as well as ChongX caps of the same specs.
High quality capacitors are most certainly more reliable than cheap brands. You can't make a cheaper anything without cutting corners. For basic stuff, a cheap capacitor will work ok, but any time you need long reliable life in more extreme or arduous conditions, then a cheap capacitor will fail earlier every time. What tests are you performing on your capacitors, and what model number are each brand?
@@NearFarMedia just ESR and capacitance with cheapo tester and multimeters. I can't recall the model numbers and I don't have the amplifier I installed them into. Just from personal experience, I've seen more name brand caps fail, pop, leak... than I've seen cheapo caps fail in the same manner.
@@aurthorthing7403 That's just one guy's experience tho.. For me, expensive caps are just for street credits. "oh boy look at these damn sexy golden japanese caps" vs "Chong"
@@giornogiovanna729 Yeah, unless I keep getting counterfeits... I don't see any value in the big boys on the block. I will mention that I have gotten some really bad caps that did not work well at all. But the majority of the name brand cheapos have been good for me and have failed less.
@@aurthorthing7403 If you are buying from Amazon, Ebay, etc, you are most probably getting fakes or maybe old stock at best. Many pieces of equipment made in the 90's and into the 00's were built with fake caps that entered the supply chain through side-channels and bean-counters looking for the cheapest price. (Google 'Capacitor Plague' and check out the 'bad caps' forum) To get the real deal, you need to buy from known good suppliers like Digikey, Mouser etc
wel erg eerlijk dat je dit in je video laat zitten, daar leren wij, ik in ieder geval, weer van. bedankt voor deze leerzame, leuke video. '73, Henk
Well done. Turned a pig into a flower. Nice save.
It just goes to show, sometimes you *can* polish a turd. :D
Ive found unstable drifting readings on the Agilent 3646A power supplies is sometimes due to bad opto couplers, I did a few repair videos on them.
Oh good tip, I'll keep that one in mind!
I believe the 10 turn pots were an extra option from HP. The original could well have been from the factory
Yeah, the single turn was factory fitted for sure, I don't see any option markings to do with the 10 turn pot, but the same goes for the colour combinations for the binding posts.
There must have been undocumented options available via the sales rep. or something.
You can wrap the shaft of the pot with good electrical tape to thicken it up a touch.
If you only need that smaller correction on the shaft, why not use heat shrink on the shaft till you get the correct thickness? Just a thought!
I knew it was the electrolytic capacitors when I seen the values jumping around.
20:35 Use some Teflontape or Scotch tape to fill the gap, then the knob will stick perfectly, and can easily be removed after if needed.
Ah! I have teflon tape too! I'll try it next time. :)
I have same model. With both dials turned all the way down, and no load, the voltage display reads 32.2, current reads .07, and both CV and CC light illuminated. Any ideas what is wrong?
First check for leaking capacitors, these units are at that age and I've seen a few now that needed new caps and a good wash to remove leaked electrolyte.
Then give it an adjustment as per the service manual and see if it comes good.
I would also suggest checking the service updates for a few mods that will help improve the power supply too.
Use vinegar to neutralize that dielectric.
I'm not convinced that expensive caps are better or last longer than cheaper caps.
I have some 3200 uf Nichicons that don't test as well as ChongX caps of the same specs.
High quality capacitors are most certainly more reliable than cheap brands. You can't make a cheaper anything without cutting corners.
For basic stuff, a cheap capacitor will work ok, but any time you need long reliable life in more extreme or arduous conditions, then a cheap capacitor will fail earlier every time.
What tests are you performing on your capacitors, and what model number are each brand?
@@NearFarMedia just ESR and capacitance with cheapo tester and multimeters.
I can't recall the model numbers and I don't have the amplifier I installed them into.
Just from personal experience, I've seen more name brand caps fail, pop, leak... than I've seen cheapo caps fail in the same manner.
@@aurthorthing7403 That's just one guy's experience tho.. For me, expensive caps are just for street credits.
"oh boy look at these damn sexy golden japanese caps" vs "Chong"
@@giornogiovanna729 Yeah, unless I keep getting counterfeits... I don't see any value in the big boys on the block.
I will mention that I have gotten some really bad caps that did not work well at all. But the majority of the name brand cheapos have been good for me and have failed less.
@@aurthorthing7403 If you are buying from Amazon, Ebay, etc, you are most probably getting fakes or maybe old stock at best.
Many pieces of equipment made in the 90's and into the 00's were built with fake caps that entered the supply chain through side-channels and bean-counters looking for the cheapest price. (Google 'Capacitor Plague' and check out the 'bad caps' forum)
To get the real deal, you need to buy from known good suppliers like Digikey, Mouser etc