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F-3000 Digitally Display Circuit Board(Stock number 7597971)

M

mleonc

Sansuier
Hi! My first post on the forum, what I'm sorry that is for looking for a part.
I've receive a Sansui G-7700, which was sitting on a garage, getting all cover of dust. After some cleaning, I had noticed that the digital display was broken. I plug the device, and for my surprise it turns on. Then I began testing it and it sounds amazing, even better than my Fisher RS-727. I can't turn to any station because the broken display, I don't know why even using the analog display(needle).

My questions are: the display can be fixed? or I have to replace it? It comes with the board?

Thanks!
 
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Right, the old digital display failure. Well youre right, the G-7700 is a monster, the dark horse in the Sansui line. I have two one which has a hybrid poweramp output section, but I love them. Im a fan!!
So tell me, does the receiver actually work, as in it picks up stations, (make sure the FM muting is off)?
But the digital readout just malfunctions, either with sections not showing or its frozen?
Well what happens is the digital chip which controls the display and quartz lock has failed. Its the large one MSM5540RS (40 pin).
They are obsolete and hard to get but I just got one from here.
http://ceitron.com/store/advanced_s...sid=08a8aee4d8c9a409a0267dc7151abf41&x=7&y=11

If you replace that chip, the tuner will roar into life....................

Welcome to AK, glad to help someone with a big G!!
 
kevzep said:
Right, the old digital display failure. Well youre right, the G-7700 is a monster, the dark horse in the Sansui line. I have two one which has a hybrid poweramp output section, but I love them. Im a fan!!
So tell me, does the receiver actually work, as in it picks up stations, (make sure the FM muting is off)?
But the digital readout just malfunctions, either with sections not showing or its frozen?
Well what happens is the digital chip which controls the display and quartz lock has failed. Its the large one MSM5540RS (40 pin).
They are obsolete and hard to get but I just got one from here.
http://ceitron.com/store/advanced_s...sid=08a8aee4d8c9a409a0267dc7151abf41&x=7&y=11

If you replace that chip, the tuner will roar into life....................

Welcome to AK, glad to help someone with a big G!!
Click to expand...

Welcome to AK, and good luck with the "G"!
Another source would be to takke one from a T-80 tuner, you can find them inexpensively, and it will have the parts you need.
Casey
 
kevzep said:
Right, the old digital display failure. Well youre right, the G-7700 is a monster, the dark horse in the Sansui line. I have two one which has a hybrid poweramp output section, but I love them. Im a fan!!
So tell me, does the receiver actually work, as in it picks up stations, (make sure the FM muting is off)?
But the digital readout just malfunctions, either with sections not showing or its frozen?
Well what happens is the digital chip which controls the display and quartz lock has failed. Its the large one MSM5540RS (40 pin).
They are obsolete and hard to get but I just got one from here.
http://ceitron.com/store/advanced_s...sid=08a8aee4d8c9a409a0267dc7151abf41&x=7&y=11

If you replace that chip, the tuner will roar into life....................

Welcome to AK, glad to help someone with a big G!!
Click to expand...

Hi!, I managed to make the tuner to work. From the schematic of the device, I unplug the white plug which has the 11-14 numbered connectors. The receiver starts receiving all the stations fine, tunning with the needle. I also take apart the whole F-3000 board from the receiver and the damage apears to be the display itself, it's broken(cracked and parts fell off) from the right side.
 
nosirrah said:
Welcome to AK, and good luck with the "G"!
Another source would be to takke one from a T-80 tuner, you can find them inexpensively, and it will have the parts you need.
Casey
Click to expand...

I had a bit of a chuckle when I read that, I managed to find a T80 which cost next to nothing.
I mean its a good idea and I certainly went for it..............
I transplanted the chip out of it, and it worked for about 5mins, and then went all crazy on me and failed, so I ended up getting one those guys in the link.
You could have better luck than me, but at least getting a new chip will get you more mileage.

But anyway theres a couple of options .
 
mleonc said:
Hi!, I managed to make the tuner to work. From the schematic of the device, I unplug the white plug which has the 11-14 numbered connectors. The receiver starts receiving all the stations fine, tunning with the needle. I also take apart the whole F-3000 board from the receiver and the damage apears to be the display itself, it's broken(cracked and parts fell off) from the right side.
Click to expand...

Oh right, ha, look at us all jumping to conclusions. In that case the best thing as Casey said would be to locate a T60 or T80 tuner and salvage the F3000 board complete from it, and I think you will be in business.
I havent looked at the schematic so Im not sure what part the connector is powering, but that failure may have taken something else out too.
But if you get one of those tuners the board should transplant straight into it.
There are two different evolutions of the G-7700, if you have the earlier one the board will fit if its the later one you will have to transplant components.
If you post the serial number I could tell you.
Or have a look underneath with the bottom off and tell me what output transistors are in there.
If there are only 4 in total and one is a 2SC2774 you have a late model, if its 8 in total and some are 2SC2581 its an early one and the T60/80 F3000 board will fit.
 
kevzep said:
Oh right, ha, look at us all jumping to conclusions. In that case the best thing as Casey said would be to locate a T60 or T80 tuner and salvage the F3000 board complete from it, and I think you will be in business.
I havent looked at the schematic so Im not sure what part the connector is powering, but that failure may have taken something else out too.
But if you get one of those tuners the board should transplant straight into it.
There are two different evolutions of the G-7700, if you have the earlier one the board will fit if its the later one you will have to transplant components.
If you post the serial number I could tell you.
Or have a look underneath with the bottom off and tell me what output transistors are in there.
If there are only 4 in total and one is a 2SC2774 you have a late model, if its 8 in total and some are 2SC2581 its an early one and the T60/80 F3000 board will fit.
Click to expand...

Hi! thanks for all the help! The serial number is: 819031635
 
mleonc said:
Hi! thanks for all the help! The serial number is: 819031635
Click to expand...

Your one is an early one according to the service bulletin. Also the clue was the digital display board is a F-3000, whereas in the later ones it was a F-3220. Of course I have one of each.
So what that means is if you find a T60 or T80 the board is a F-3000 and it will take all of 5mins to transplant it and have your tuner up and running.

There is a chance that MSM5540 chip is toast, so make sure when you get a donor unit the tuner is fully functional.

Oh I forgot, I think one of the guys posted a link to the Sansui Parts Shop. Definitely have a look there, Ive bought many things from this guy and found him to be very good.
 
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kevzep said:
Your one is an early one according to the service bulletin. Also the clue was the digital display board is a F-3000, whereas in the later ones it was a F-3220. Of course I have one of each.
So what that means is if you find a T60 or T80 the board is a F-3000 and it will take all of 5mins to transplant it and have your tuner up and running.

There is a chance that MSM5540 chip is toast, so make sure when you get a donor unit the tuner is fully functional.

Oh I forgot, I think one of the guys posted a link to the Sansui Parts Shop. Definitely have a look there, Ive bought many things from this guy and found him to be very good.
Click to expand...

Thanks again for all the help, gonna find the donor and I will catch up what happens with my new receiver. Thanks!
 
mleonc said:
Kev, how is different a G-7700 "stock" from a hybrid?
Click to expand...

Well to cut a long story short, I bought my first G-7700 in good faith, got it home listened to it to only to disappointed with the sound.
I opened t up to find a "dime store" kitset power amp in it. The silver part of the heatsink (the part attached to the black external heatsink) was gone. along with the power transistor assembly. In its place was this "thing".
The only thing left was a very damaged driver board and the external part of the heatsink.
I bought a new driver board from the sansui parts shop (very Lucky).
I got NOS output transistors from the same place, fabricated a way to attach it all to the heatsink.
I had to make up a thermal current regulation circuit, VBE multiplier, because the thermal current regulating diodes are not available now.
Then when I fired it up for the first time I made an error, and blew up the transistors.
By a stroke of luck I came across for free, (out of our ex Carver stock) some output transistors which were very similar, higher voltage HFE, fT, and higher current, but it looked like they would be a good sub.
They are Toshiba OP's from a Carver PT1250 professional amplifier.
Put it all together and it runs.
I just love the sound of these amps, very clean and plenty of punch.
Couple of threads on it here.


last thread here

http://www.audiokarma.org/forums/showthread.php?t=316928

First thread here

http://www.audiokarma.org/forums/showthread.php?t=312264
 
Rob, as usual, is correct, the T-60 doesn't have a digital display, analog only.
Maybe the R 30 or R 50 receivers? I have a 50 but it's stored away someplace in the basement of the Museum.
 
nosirrah said:
Rob, as usual, is correct, the T-60 doesn't have a digital display, analog only.
Maybe the R 30 or R 50 receivers? I have a 50 but it's stored away someplace in the basement of the Museum.
Click to expand...

Yeah, I cant remember where I got that from, could be me misinterpreting something I read, they could have said T80 not T60 or something. The OP's problem was more than just the MSM chip too, Just pays not to jump to conclusions like I did as to what the fault was.
But I think the OP got some good info from us and he's on his way with a good repair plan. So :thmbsp: all round
 
Repaired!

Hello! I'm posting the images of the repaired G-7700. I've managed to find a donor receiver and replace the broken display.

God I love this receiver!:music:
 

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