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Quad Sansui problem; help???

Trnsfmr said:
OK, that was a hard one to figure out. It is under through hole, wire wound. Here's the part #
280-CR5-3.9-RC

Put that part number in at the top of the page and it should get it for you.

Those resistors are 3.9K, I think, at least on all the 9001's I've seen so far, the one on the bottom of the caps. I actually like to replace them with 10k 1/2 watt.
Click to expand...

I just realized that what I said could be confusing.

The resistors next to the relay are suppose to be 3.9 ohms. The K when it appears after the ohm symbol, means 10% I think. that's the one I gave you the part number for.

The resistor on the bottom of the cap is 3.9K ohms. 3,900 ohms 1/2 or 1 watt. I like to replace those with 10,000 ohms 1/2 watt. 10Kohm 1/2w. You will find that if you try to reuse these, they will be hard to unsolder and then doubly hard to attach to the new caps.

Albert, at some point you will start to learn the color code, but just as good, and more reliable with less mistakes, is to use your meter and measure it. You see a resistor and you don't know what it is, measure it. Realize that if you measure it in circuit, it probably isn't accurate, but for example, the one on the big caps should measure 3.9K, after your meter gets done charging the cap up. :scratch2:

I have one nice meter like Kev showed you, and lots of cheap ones. I have several like you have, and they work great and are accurate, and are cheap to replace if you need to. I got two sons going to college, and I know how tight money is for them (and for me, supporting them), and probably is for you.

You know, you will probably learn a tremendous amount about electronics from doing this repair. Try to incorporate what you're learning in school to what we are doing here. spend some time studying the various components we are going to replace.

When we get to the end, you will have probably hundreds of different posts in this thread. You might wanna print out some of it and show your instructor. Make this into a course project.
 
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joekid said:
:tears:You no before this is said an done there is going to be :dammit:times:scratch2:thinking times:dunno:da times:O and yes:withstpd:times But at the end when everything come's together there will be:thmbsp::banana::beer::rockon::yippy:TIMES
Good luck and best wishes
Joe
Click to expand...

Hey Joe,
Glad to know you're watchin'. What do you think? Let's start a little pool on how many posts it takes to get this Quad Beast functioning again. We're up to 514 on the Anderslober Saga and it's not completely fixed yet. But that one was really bad, it had even had a pc board ripped apart and he fixed it. I think we're gonna do this one faster, maybe 400 posts. Wanna make a guess? Anyone?
 
Jim,let me think:scratch2: no mater how many post'es it will take. I no it will get fixed ,.So am still :scratch2:. Okay 491,that's a good no.


Jim,I was reading that you are looking for some knobs,parts.Show me a picture of what you need and I will look up here to see if I can fine any of them.
Take care all and good luck on your Quest.
Joe
 
Trnsfmr said:
I just realized that what I said could be confusing.

The resistor on the bottom of the cap is 3.9K ohms. 3,900 ohms 1/2 or 1 watt. I like to replace those with 10,000 ohms 1/2 watt. 10Kohm 1/2w. You will find that if you try to reuse these, they will be hard to unsolder and then doubly hard to attach to the new caps.
Click to expand...

Alright so I'm going to go ahead and buy replacements for those. Will these work?

http://www.mouser.com/ProductDetail/Vishay-Dale/CMF6010K000FKEB/?qs=sGAEpiMZZMu61qfTUdNhG3EzrPz99APhdXfjfyG%252bnPE%3d
 
Trnsfmr said:
I just realized that what I said could be confusing.

Albert, at some point you will start to learn the color code, but just as good, and more reliable with less mistakes, is to use your meter and measure it. You see a resistor and you don't know what it is, measure it. Realize that if you measure it in circuit, it probably isn't accurate, but for example, the one on the big caps should measure 3.9K, after your meter gets done charging the cap up. :scratch2:

I have one nice meter like Kev showed you, and lots of cheap ones. I have several like you have, and they work great and are accurate, and are cheap to replace if you need to. I got two sons going to college, and I know how tight money is for them (and for me, supporting them), and probably is for you.

You know, you will probably learn a tremendous amount about electronics from doing this repair. Try to incorporate what you're learning in school to what we are doing here. spend some time studying the various components we are going to replace.

When we get to the end, you will have probably hundreds of different posts in this thread. You might wanna print out some of it and show your instructor. Make this into a course project.
Click to expand...


Yes the multimeter I'm using is my dad's cheaper one, he said it would be just fine for what I'm doing. He has a nicer one but he uses it for his job. My teacher has a nice one as well.

I believe I will learn a huge amount about electronics as well, especially with gurus like you guys. I'll mention the project idea to my teacher :)
 
joekid said:
:tears:You no before this is said an done there is going to be :dammit:times:scratch2:thinking times:dunno:da times:O and yes:withstpd:times But at the end when everything come's together there will be:thmbsp::banana::beer::rockon::yippy:TIMES
Good luck and best wishes
Joe
Click to expand...


Most definitely there will, and im thinking a few of them already happened :D

Thanks for the kind words, I will try my best for sure! Like my dad says about everything thats going hard for him "I wont let this thing kick my butt." He said it about a mercedes not too long ago, and last night about Skis, neither of them kicked his butt. :lurk:
 
Hello guys, I'm back with a lot of updates.

Firstly, I received all the parts I ordered from Mouser. Also, I went and bought my own soldering kit and solder removal tool (thanks for the suggestion)

I have a friend from Costa Rica with a lot of electronics experience (he's up in the ranks of Intel) whos been helping me with my projects (I successfully recapped my Advent's crossovers). Today we started with the sansui, recapping the power supply board (and smaller one).

Some mixed news while recapping the power supply board:

-There were 4 100µf 63V capacitors that I did not have, but I did have 4 220µf 63V capacitors that I used to replace them with Please confirm I did the right thing, because I could not find any capacitors rated at 220 60

-I did not order the 4.7µf 80V caps correctly; they are supposed to be bipolar and I ordered polar :jawdrop: (I did not replace any of these)

-I did not have a single 100µf 16V that is in the power supply board. Please confirm I need to replace it.

-I did not have a 47µf 10V replacement. But I did have one unused replacement at 6.3V 47µf. Also, I had a leftover 47µf 50V that we DID put in this spot because it was higher, not lower, voltage. Please let me know if this was the wrong thing to do.

-I did use all the other caps I had to replace the old ones successfully.
• The small supply board is fully recapped.

About the driver boards:

-The underside of both driver boards had some corrosion and weird yellowing solder joints that does not show well on pictures, but I did post a picture.

-One transistor (A899 V) on the driver left driver board is burnt (picture shown). Also, on this same board, the capacitor I previously posted a picture of, I removed it.. and, it looks pretty bad (picture). Some weird bulging going on at the bottom.

• In the schematic, we followed it through the bipolar caps I did not order (4.7µf 80V) after the fuse that kept blowing. So we believe these caps do indeed need to be replaced. Please confirm that we are thinking along the right path

-Based on these signs, we believe a recap of the driver boards is probably a good idea. Is this good thinking?

-Maybe after dinner, we will replace the fusible resistors. If not tonight, tomorrow.


So I have a new list of caps to order for the driver boards. Also, I should probably go ahead and replace the transistors here right? It seems that the driver boards got a lot of stress based on how the joints look according to my friend.

Leftover caps after everything: 220µf 25V x2, and a single 47µf 6.3V :saywhat:












This was here before I got it, and I dont know why:

 
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I found this post concerning the A899:

The 2SA899 is a silicon PNP transistor, 150V, 50mA, 100MHz.
Replacements: BF470, BF472, BF416, BF418.
Click to expand...

Is this right? And if so which is the best replacement?


I cannot find them on On Semiconductor.
 
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Hi, we were wondering what happened. Yep that transistor (899) looks like it might be bad, did you test it? (just kidding) I'm busy right now for a while, but I will get on and answer all later tonite. Kevzep likes a different tr for the 899, I'm sure he'll join in later.

Later.........
 
Betomon said:
Hello guys, I'm back with a lot of updates.

Firstly, I received all the parts I ordered from Mouser. Also, I went and bought my own soldering kit and solder removal tool (thanks for the suggestion)

GOOD TO HAVE THESE TOOLS. YOU NEED THEM.

I have a friend from Costa Rica with a lot of electronics experience (he's up in the ranks of Intel) whos been helping me with my projects (I successfully recapped my Advent's crossovers). Today we started with the sansui, recapping the power supply board (and smaller one).

Some mixed news while recapping the power supply board:

-There were 4 100µf 63V capacitors that I did not have, but I did have 4 220µf 63V capacitors that I used to replace them with Please confirm I did the right thing, because I could not find any capacitors rated at 220 60

THE SCHEMATIC SAYS 220. THESE WILL BE FINE

-I did not order the 4.7µf 80V caps correctly; they are supposed to be bipolar and I ordered polar :jawdrop: (I did not replace any of these)

JUST ADD THESE TO YOUR NEXT ORDER, THE OLD ONES ARE PROBLY OK TO START WTIH.

-I did not have a single 100µf 16V that is in the power supply board. Please confirm I need to replace it.

IT'S A GOOD IDEA TO REPLACE THEM ALL. SINCE YOU ARE GONNA BE WORKING ON THIS FOR A WHILE, JUST ADD IT TO YOUR NEXT LIST FOR ORDERING.

-I did not have a 47µf 10V replacement. But I did have one unused replacement at 6.3V 47µf. Also, I had a leftover 47µf 50V that we DID put in this spot because it was higher, not lower, voltage. Please let me know if this was the wrong thing to do.

THAT'S FINE, HIGHER VOLTAGE IS OK, LOWER IS NOT.

-I did use all the other caps I had to replace the old ones successfully.
• The small supply board is fully recapped.

About the driver boards:

-The underside of both driver boards had some corrosion and weird yellowing solder joints that does not show well on pictures, but I did post a picture.

THEY ALL LOOK LIKE THAT, NO WORRIES.

-One transistor (A899 V) on the driver left driver board is burnt (picture shown). Also, on this same board, the capacitor I previously posted a picture of, I removed it.. and, it looks pretty bad (picture). Some weird bulging going on at the bottom.

• In the schematic, we followed it through the bipolar caps I did not order (4.7µf 80V) after the fuse that kept blowing. So we believe these caps do indeed need to be replaced. Please confirm that we are thinking along the right path

THESE CAPS ARE NOT CAUSING A FUSE TO BLOW, THAT MUCH CURRENT THROUGH ONE OF THOSE LITTLE CAPS WOULD BLOW IT UP. I JUST BLEW UP A CAP THE OTHER NITE, IT'S VERY NOTICEABLE.

-Based on these signs, we believe a recap of the driver boards is probably a good idea. Is this good thinking?

THERE'S VERY FEW CAPS ON IT. IT'S FINE TO DO, ESPECIALLY IF YOU HAVE FOUND A BAD ONE. ONLY REPLACE THE ELECTROLYTICS, LEAVE ALL THE OTHERS ALONE.

-Maybe after dinner, we will replace the fusible resistors. If not tonight, tomorrow.

THE FUSIBLE RESISTORS ARE THE MOST IMPORTANT THING TO CHANGE ON THE DRIVER BOARDS. I POWERED UP A 9001 FOR THE FIRST TIME AFTER RECAP THIS MORN. BEFORE THE RECAP IT HAD ONE BAD CHANNEL WITH 14V ON THE OUTPUT. CHANGING THE FUSIBLE RESISTORS BROUGHT THAT CHANNEL BACK IN LINE.


So I have a new list of caps to order for the driver boards. Also, I should probably go ahead and replace the transistors here right? It seems that the driver boards got a lot of stress based on how the joints look according to my friend.

DON'T GO CHANGING TRs UNLESS THEY MEASURE BAD, OR LOOK KINDA SICK, LIKE THAT 899. YOU CAN CHECK ALL THE TRs WITH THE DIODE FUNCTION ON YOUR METER. THEY SHOULD READ .5-.7 MEASURED FROM b TO c AND b TO e, ONE WAY AND HI (OR 1, OR OL, OR INF, WHATEVER YOUR METER DOES, THE OTHER WAY) DOESN'T ALWAYS WORK EXACTLY LIKE THIS CAUSE TRs CONNECT TO EACH OTHER AND TO DIODES. THEY SHOULD READ RIGHT IN THE FORWARD DIRECTION THOUGH. POSITIVE GOES THROUGH THE ARROWS THE SAME WAY THEY ARE POINTING.

INCIDENTALLY, THAT A899 BLOWS BECAUSE THE FUSIBLE RESISTORS HAVE DRIFTED WAY OFF VALUE.

Leftover caps after everything: 220µf 25V x2, and a single 47µf 6.3V :saywhat:
Click to expand...

See my all caps answers above. We changed several 899's on Anderslober's unit, I think it's an MJE430, but am not sure. You can track down that thread.

You always have more caps left over, and some are always wrong. It just goes with working on Sansuis. We always like to replace the cap as it is soldered on the board if that is different than the schematic. Those 220's are on later boards, they won't cause a problem.

Now, don't be tempted to power up once you get this work done. There's a very specific sequence for powering up such a complex unit. And especially when you have fuses blowing and channels not working. Kevzep is much more experienced with that, so he will lead you through it. I have more experience with the 9001, so I will be throwing in suggestions too, but Kev is the power amp guy.

Now, let me tell you something that is very important for working on something as big and complex as the 9001. YOU WILL MAKE MISTAKES. That's OK. The really important thing is to find them before you power on. This means checking everything you do at least twice, and if you have someone working with you, have them check it twice too. In my shop we don't count a mistake as a mistake unless it makes it to the power on phase. In other words, a mistake that you find by checking your work is ......guess what?....... not a mistake. A mistake is putting a 220uf @ 25v cap in where a 220uf @ 50v belongs, and then getting the little explosion and mushroom cloud later. That's what I did on our shop test 9001 and it took months for it to blow up, but it did finally, two nites ago.

We're on our way here. :yes:
 
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The substitute for the 2SA899 V is MJE350, 300V PNP...... these are readily available, onsemi, mouser, digikey or wherever you are buying from......

Make sure it is in a TO-126 casing because they also come in TO-220 casings...........the pin-out goes ECB (with the label towards you) NOT EBC like a TO-92.

FYI the NPN complimentary pair for the 350, is MJE340........
 
anderslober said:
I used a 2sa1142 as sub for the 2sa899.................mje350 is also good.
Click to expand...

The 1142 are not readily available because they are no longer stocked as they are now obsolete, Im listing things Albert will be able to order from the local suppliers.......
 
Trnsfmr said:
See my all caps answers above. We changed several 899's on Anderslober's unit, I think it's an MJE430, but am not sure. You can track down that thread.

You always have more caps left over, and some are always wrong. It just goes with working on Sansuis. We always like to replace the cap as it is soldered on the board if that is different than the schematic. Those 220's are on later boards, they won't cause a problem.

Now, don't be tempted to power up once you get this work done. There's a very specific sequence for powering up such a complex unit. And especially when you have fuses blowing and channels not working. Kevzep is much more experienced with that, so he will lead you through it. I have more experience with the 9001, so I will be throwing in suggestions too, but Kev is the power amp guy.

Now, let me tell you something that is very important for working on something as big and complex as the 9001. YOU WILL MAKE MISTAKES. That's OK. The really important thing is to find them before you power on. This means checking everything you do at least twice, and if you have someone working with you, have them check it twice too. In my shop we don't count a mistake as a mistake unless it makes it to the power on phase. In other words, a mistake that you find by checking your work is ......guess what?....... not a mistake. A mistake is putting a 220uf @ 25v cap in where a 220uf @ 50v belongs, and then getting the little explosion and mushroom cloud later. That's what I did on our shop test 9001 and it took months for it to blow up, but it did finally, two nites ago.

We're on our way here. :yes:
Click to expand...



Yes I agree with you 100% This thing wont be powered on until I make sure with myself and you guys that its fine to be powered on.



So as I am going to have to order caps, I'm going with Mouser on this one. And this is my list so far:

100µf 63V
10µf 50V
330µf 63V x4
470µf 6.3V x4
100µf 25V x4
4.7µf 80V Bipolar x8

MJE350 x2 TO-126
MJE340 x2 TO-126
(Im going to go ahead and replace them all)

But, I'm thinking of just getting everything I need at once. Also, I'm considering a full recap so that I dont have to go to Mouser later.

Do you guys think I should replace the other NEC transistors on the driver boards?

Right now the big caps and their resistors are done. Now we are going the driver board's resistors.

I want to put the order in as soon as possible to get the parts here before my friend has to leave (MONDAY! :( )



I think I'm making progress too, thanks to you guys :)
 
Hi Betomon,
A recap is a good thing. I would strongly suggest that you wait until we get her up and running, with all 4 channels functioning, first. Then you can do the recap one board at a time, plug it back in and then, if you have a problem, you know it was on the work you just did.

You will need to order more parts as we go along, I'm sure of it, so just hold off on the big recap order til you get there.

Your parts order looks fine. Be careful with those resistors, for some reason I find it really easy to make mistakes on those driver boards.

Have you checked the TRs on the driver boards? Really, you can make more problems than you solve by just changing them out for no reason. If you want to order some of the TRs, ok, they are cheap. But don't change them until needed.

:music:
 
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