Discussion in 'Exclusively Sansui' started by Willy6, Aug 17, 2017.
Wooh-Hooo ! - congratulations.
I was lucky and all of the original outputs tested good..
Here are the parts replaced so far F-2839
Just about ready to put the guts back in.F-2844 done with 12 parts replaced.
Not as good as yours Kale but it does the job..
got one oval cap in to hold the power supply board F-2845 down..
Did you use your Peak Atlas DCA 75 to pronounce those transistors and diodes dead / shorted or low Hfe?
I use threads like this as my schooling, so I hope to hear why certain decisions were made so I can copy your process.
Thanks for the great thread!! BTW
Yes I started checking transistors with the peak atlas and found a few shorted so I decided to replace all of them accept the drivers because they tested good and I didn't have a replacement for one of them.As for the diodes I always change the zenners and the small 1s2473's when I see them..
Working on F-2835 now and I was able to get the corrosive blackish brown glue cleaned up removed quite a few infected resistors,capacitors and transistors and ready to move forward..I wonder if those two blue trimmers should be replaced?They appear to be sealed..
I recommend you replace them, they are enclosed but not airtight, which means they can have oxidised inside, and cleaning them is impossible.
Just noticed you have a set of Klipsch Forte's in the background. My restored 717 makes them sing nicely what with Crite's upgrades, will be interesting to hear your thoughts once you get the 919 rebuilt.
Yep those forte's should match up with the 919 nicely..
Congrats on reaching 1000 posts sir
Well I got F-2840,F-2833,F-2835 and F-2841 all done and everything buttoned back up today..I did the bias and dc offset adjustments on my dbt with a 150 w bulb..set all of the other trimmers to the middle position and then plugged it directly in to the wall and let it warm up for 10 min and found that on F-2835 I was able to set the right side at 0 mv but the left reads 425v Luckily that board is easy to get to..and also F-2833 is giving me a headache..I was able to set the right channel vr04 and vr06 both to 1
0mv but I could only get around 30mv on the the left vro3 and vro4 time to check resistors on that board I think.
I think I need bigger trimmers in F-2835 the ones I pulled out said 330 on them but the manual says 220 ohm and since I didn't have any 330 ohm I put the 220's in there and they wont adjust down far enough the only Biggers ones I have are 500 ohm guess I'll put those in and see what happens.
Dont have the schematic handy however are there any fuseable reistors on that board and if so and you changed them out perhaps a mistake in replacement resistor value?
Take a look here at this link - http://www.audiokarma.org/forums/index.php?threads/new-addition-au-919.467393/page-4#post-6114448 - I used 200ohm - and had no problems.
Are you sure you have the right value trimmers in there now, perhaps measure them?
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