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Is it possible I took out a transistor by powering it up with the wrong resistance pots? I did after all have 1k pots instead of 100k pots!
 
Dod you feed any signal through it? How long was it on for? I don't really know enough to know if ll that extra impedance would damage anything but I would swap them out with the originals and power up on a dbt. If it passes, odds are the semiconductors are ok.
 
No signal fed through. I'ms tarting to suspect the transistors I bought to replace the old noisy ones may be counterfit or bad. I tried to get NOS japanese ones. I should have just bought the fairchild ones from mouser. This weekend I'm going to take everything off the board and check everything and start over. IN the meanwhile maybe you guys can answer this. So this is a pre 3000 serial# champagne face unit. It has a set of extra 1000uf filter capacitors. In addition to the 6800uf filter caps. Tracing the wiring back reveals these caps are just connected in parallell with the 6800uf caps. Why on earth would they do this? Can I just get rid of those 1000uf caps and just spec out 7800uf caps?I also noted in the parts list in the original manual the caps are listed as 9000uf. But the schematic in the same manual has them as 6800uf? Anybody else do a champagne face and come across this?
 
Are you sure you have the replacement transistors in correctly? The pinout may be different from the original whatever-they-were ones.

They couldn't get the value they wanted at first on the main filter caps so did the two in parallel is my guess. You'll do much better sourcing an 8200uF as it's a standard value, of course dropping the secondary 1000uF's.
 
rBuckner, that's a good point. I tested them with my transistor checker before putting them in and they tested correctly with the orientation I installed them. Which also matches the orientation on the data sheet as well. But I thought I would pull them off again and test them tomorrow. We are supposed to be frozen in doors all weekend so I have plenty of time to work on this over the weekend. (I'm sure my wife will want to go see zoolander 2 at some point though. lol) I originally sourced Nichicon Fine gold 6800's and a pair of Silmic 1000uf before I realized these caps where just in parallel. Interestingly with the purchase of this unit I got a supplement manual for the pre 3200 serial number units. I noticed Hifi engine did not have this manual so I'm going to scan it in this weekend. Do they keep a manual archive here on this site? (If so I'll add it here as well.) But back to my point, those 1000uf caps are not on the schematic for the pre 3200 serial units either! So I think your speculation may be correct! I took the main filter caps out last night. Interestingly they test good. In fact one of them is right on the money! One final question for the AK'ers out there. are there any 8200uf caps that fit the size of the mounting rings? My kid kind of claimed squatters rights on my micrometer for measuring when we got him his 3d printer. So I'm not sure what size these are. I guess I should quit being lazy though and search the forum as I'm sure somebody has already mentioned this. I mean it is a pseudo snow day/slow day here at work today anyways. ;)
 
I wouldn't take the transistors out, just compare to what is silkscreened on the board. Those FG's are nice caps so you could just use what you already have and I bet you'll be happy. You can just measure the caps' diameter by eye with a ruler and search for 8200uF and the diameter on Mouser's website even if you use some other vendor. I believe you select "passives", then electrolytic caps, then I suggest looking at "snap in leads" for this large of a part and also check the "smart search" and "in stock" checkboxes.

Yes there is a database but it's at www.akdatabase.com. I'm pretty sure there's a 2245 manual there but take a look at the quality, you may be able to improve on it. Then everybody will love you!

I just saw the local paper review that movie as 2 out of 5 stars so maybe pray for more ice and snow. :-)
 
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