Sansui G-9000DB Repair And Restoration
This Sansui G-9000DB is still operating but is in need of some service.
As with all the vintage stereo equipment using deoxit on the pots and switches is a must.
Almost always you must do some disassembly to properly clean the controls on any piece of vintage stereo equipment.
The controls are back in and it's time to do a quick check to make sure the Sansui G-9000DB is still working.
With the faceplate off it's a good idea to protect the dial face from dust, a screwdriver or other hazards. I've used some bubble wrap and tape.
Lay out your parts in a way that you can get everything back together correctly. For example, sometimes screws are not the same lengths.
I'll be installing new capacitors in the power supply of this Sansui G-9000DB Receiver.
I also will be installing new Omron relays. Many vintage stereo repairs and restorations involve new capacitors and relays.
Service manuals are not always accurate. The only way to make sure what parts you need is to take a look inside the unit and make a list.
Once you have your list you can order the needed parts for your Sansui G-9000DB repair or restoration.
You need to remove some modular plugs along with removing wires that run through the channels that keep the wires neat within the chassis.
It's never a bad thing to mark your connectors and take a picture before you remove them. Can you mix these up? The answer is yes.
Once you get the connectors removed and the wiring loosened up along with a couple of screws you will be able to move the assembly.
If your Sansui G-9000 has discolored connector pins like the picture below a pencil eraser will bring them back to looking new.
After using a pencil eraser the connector pins look much better and should stay that way for many years.
You will find that there will be enough slack in the wires to move the Sansui F-2809 power supply and protector assembly 90 degrees.
With the Sansui G-9000DB on it's side and the F-2809 assembly at a 90 degree angle I will be able to get to the artwork side of the F-2809.
I have tucked all of the previously removed connectors into a space at the back of the chassis to give them some space from the soldering iron.
Tie wraps make for a much needed third hand as well as taking the strain off of the 40 year old wires.
I'm about ready to start the parts replacement procedure for this Sansui G-9000DB receiver repair and restoration.
The Hakko 808 desoldering tool makes the replacement of components easier. The 808 is also safer for the artwork pads that can be damaged.
How 40 years has changed capacitor size. The picture shows a 40 year old 220uf 35V capacitor along with the new 220uf 50V modern replacement.
Working from the top down I have replaced about half of the capacitors in this Sansui G-9000DB's power supply.
Two Omron LY2-0 and One Omron MY4-02 are exact replacements for the Sansui G-9000DB. These are both DC 24 volt relays.
I'll replace any diodes that are known to be failure prone and replace them with modern equivalents.
The two 6.2 volt zener diodes tested a little bit off so they were also replaced. One tested at 6.5 volts and the other at 5.9 volts.
It's a good idea to wear a properly grounded static strap when repairing or restoring vintage solid state stereo equipment.
I have removed the two heat sink mounted transistors from this Sansui G-9000DB F-2809 power supply assembly.
I will not replace the heat sink mounted transistors TR05 AND TR06 as they have a good record of being reliable even after decades of use.
I will clean the transistors and the heat sinks with 91% isopropyl alcohol. I then will apply a thin layer of new thermal compound and reinstall.
Some of the capacitors in this Sansui G-9000DB receiver are "non-polar" or "bi-polar". Both terms mean the same thing.
The picture below shows the original blue capacitor with "NP" for non-polar. The replacement capacitor is stamped "BP" for bi-polar.
I'm about ready to reinstall the F-2809 power supply back into this Sansui G-9000DB receiver.
I have now loosened the F-2799 tone control assembly from this Sansui G-9000DB receiver.
With the F-2799 assembly loosened I can get to the F-2810 RF power supply assembly to replace capacitors.
After removing a couple of screws and getting some slack in the wires I can now get to the artwork side of the F-2810 assembly.
Give yourself as much space from the wiring as you can when soldering. Ask me how I know that's a good idea, LOL.
The capacitors in the F-2810 assembly have been replaced. The Sansui G-9000DB uses the F-2810 to supply voltage to the tuner section.
This Sansui G-9000DB repair and restoration will include replacing the capacitors on the F-2799 tone control assembly.
You need to unsolder three tabs to remove the shielding cover on the F-2799 to be able to access the components.
With the cover removed on this Sansui G-9000DB solid state receiver I'm now able to get to all of the components easily.
Any vintage audio repair or restoration including this Sansui G-9000DB is cleaning the pots and switches. The picture below is the volume control.
Using tie wraps is a great way to have that third hand when needed. You can put the assemblies where they are easier to work on.
When you need an assembly at a different angle just cut the tie wrap you were using and put the new tie wrap where you need it.
This Sansui G-9000DB repair and restoration is getting closer to completion. After capacitor replacement, I'm ready to now reinstall the F-2799 assembly.
This Sansui G-9000DB receiver had an issue with the right channel idle current not being able to be adjusted properly.
Normally the issue with idle current would be a problem with the driver assembly. Not the case in this particular Sansui receiver.
The 9000DB is back together and now all amplifier specs can be set properly with the idle current now meeting specifications.
All of the information to service this Sansui G-9000DB receiver is available online.
All seems well on the test bench. This Sansui 9000DB receiver repair and restoration is complete..