Sansui G6700 220 volt??????

These look good. Now you need the service manual (SM).

Go to www.hifiengine.com and register (free). Then go to LIBRARY. Scroll down until you see SANSUI, and click on it. Scroll down and click on G-6700. Now scroll down and click on "service manual". That should get you an 8 Mb PDF file that covers the 5700,6700&7700.

Take lots of photos from all angles of the installed F-3000 bds in both systems. There may be slight differences in how all the jumpers appear to be wired in, but they are probably the same. The schematic shows 20 wires going to this board. Some may be going thru removable connectors, but this depends when each unit was built.

Take notes on where each wire goes, and the color of each jumper, in both chassis.

Please report your progress, success and difficulties here.

fuses and F3000 Boards

I received a replacement F3000 Board today and it is identical to the first unit that has a cracked frequency display. The wired plastic plugs go in randomly around the board. A second non-working G6700 arrived today and the F3000 board in this one is wired differently. The wired plastic plugs are attached in rows outside the metal chassis carrier on each side. I will do the swap on Friday of the identical F3000 boards and post photos here.

Now a question on the main fuse?????
First unit main fuse is a AGC7 32 volt fuse (the working unit)
The second (non working unit) fuse had an 8A 250 volt fuse that looked newer.
I swapped the AGC7 fuse into the second unit and still no go, so it is dead.
A unit set to run on 120 volt current is supposed to have a 7amp fuse, but what is the correct voltage for these fuses?

I will get the service manual tomorrow as it may specify the fuse.

The main fuse is spec'ed as 7amp, 125V (I think that a 7A 250V will be OK), and the other three are spec'ed as 2amp, 250V. ANYTHING larger is just inviting disaster, and anything lower will likely blow out at some point. Always replace fuses with the values specified in the SM or the schematic unless you have a validated reason for the change.

Further troubleshooting will require some resistance measurements, and the output transistors are a good place to start. Let us know when you get your SM. You can start by looking at some of the photos I posted in my thread. Posts # 8, 27, 89 & 90.

walking dead

OK here goes.
2 G-6700s in the family now.
Unit 1 sound is great but the digital display did not work and was cracked.
Unit 2 bought as a non working unit

Unit 1 removed and replaced the F3000 digital display board.
Unit 1 digital display is now working
The unit 1 F3000 board has 7 plug in connectors around perimeter of the board and 2 screws that mount it to the front panel, really easy to change out.

Unit 2 walking dead unit

Unit 2 was not working until I took out the 8A fuse that came with it and replaced it with a 7A fuse. This is the walking dead unit. I bought it for parts but after it lit up with the fuse change I think it will be restored. It powers up, the FM/AM seems to receive signals but no sound comes out. The green protection light never comes on but it is not dead yet. (Monty Python)
Notice that the F3000 board in this unit is built differently that the one in unit 1. The wiring plugs in outside the metal frame of the board. I noticed that the cooling fins on the back of unit 2 are squared off with sharp edges while unit 1 has chamfered and softened edges., just a different manufacturing process I guess.

A nice score!

I am guessing that #2 was manufactured later than #1. Go to this thread and read post #5 to find out how to read the date codes.

http://www.audiokarma.org/forums/showthread.php?t=144580

You will need to resolve the Safe Operate issue before you can hear anything. That relay keeps the speakers isolated until certain conditions are met.

IMPORTANT: Be very careful when measuring anything with power applied. You could hurt yourself, damage your test equipment, or destroy parts of the receiver.

If you plan to work on this receiver with power applied and do not have a DBT, STOP. Research and read about Dim Bulb Testers here on AK, and build one before you proceed.

Check the DC Offset and Bias voltages first. There are any number of explanations and instructions here on AK. This is a basic first step after you have "lights". Ask questions if there is something you do not understand. Be patient, and don't blunder into unknown territory.

Be careful with the 100Ω single turn trimmer pots on the main board (F-2980) as they don't always age well. I would suggest replacing them with 25 turn Bourne type trimmers before you start doing any repair or refurb work.

You will need to check out as many functions and operations as possible/practical, and take good notes. The sum total of all your knowledge of this receiver will help you (and us) narrow down the things to be checked.

G-6700 issues resolved

To follow up with everyone on that followed this thread. Unit #1 had a bad capacitor in the protection circuit and once replaced allowed the unit to function properly. However we went on and replaced 53 other capacitors and one relay to totally refresh the unit. It really does sound incredible now.

The second unit had a bent internal chassis and a broken circuit board and we decided not to spend any money on that one.

curious if the 2nd unit is for sale! or if the f3000 board is still available from that unit!