Sansui solid state 7000 repair, recap, and restore

The tuning dial lamps and function indicator lamps are in an unusual... place. Or, unusual to get to, actually.

There is a two-sided metal cover over top of the wires leading to the function indicator lamps. You can remove that cover by three screws exposed via holes in that same cover.

There is a single electrolytic cap sticking out from underneath this cover... and once you remove the cover you find there is a diode and two resistors under that cover. Sheesh. Why?

Lamps 01 IMG_7965.JPG

Lamps 02 IMG_7964.JPG

Lamps 03 IMG_7966.JPG

Lamps 04 IMG_7967.JPG

Lamps 05 IMG_7970.JPG

Lamps 06 IMG_7971.JPG

Lamps 07 IMG_7988.JPG

Lamps 08 IMG_7989.JPG

Lamps 09 IMG_7992 2.jpg

The fuse style tuning dial lamps get replaced with 8V LED warm white LED modules.

The wheat bulb lamps for the function indicators and the meter lamps will need to be replaced with T1 3/4 size 6V AC wheat bulbs. There ins't enough remove to add diodes and caps to run LEDs.
 
will be curious to hear your thoughts on how it sounds when all done. I wonder if it sounds more like a 2000/4000/5000 or seven/eight/eight delux
 
On the rear panel, underneath the manufacturer's label, there is a box that covers over the voltage selector... plugs. It looks like you could very carefully select the AC mains voltage going into the unit.

View attachment 1145512

View attachment 1145513

View attachment 1145514

View attachment 1145515

I think I've got 120 VAC here and I don't want to push the circuitry over its edge, so I'm going to select 127 VAC.
You will probably find this out on your own after you plug it in set like that....but you will end up with excessive distortion due to being under voltaged. The jumper is supposed to be set to 117v for the US market. Your line voltage may be "120" but its usually closer to 117-118v and is not an issue for these.
 
You will probably find this out on your own after you plug it in set like that....but you will end up with excessive distortion due to being under voltaged. The jumper is supposed to be set to 117v for the US market. Your line voltage may be "120" but its usually closer to 117-118v and is not an issue for these.

The very first test of the unit will be the power supply outputs. Any problem with voltage selection will be pretty obvious.
 
Nice work ! Those 3 screws holding down the lamp cover caused a short on my Eight lamp rail - entirely my fault - turned out a wire got stripped as it was halfway stuck underneath one of the screws as I snug it down.
 
will be curious to hear your thoughts on how it sounds when all done. I wonder if it sounds more like a 2000/4000/5000 or seven/eight/eight delux

I suspect it is closer to the 5000 (at least it is, in terms of topology).

Thank you to the OP for all of the excellent pictures and documentation.
 
....but you will end up with excessive distortion due to being under voltaged. The jumper is supposed to be set to 117v for the US market. Your line voltage may be "120" but its usually closer to 117-118v and is not an issue for these.

Setting to the voltage selector to "117V" is fine. So is using "127V", its not going to cause any excessive distortion in by itself; a 5% lower power supply rail voltage is not that significant. One can monitor the voltage at the main capacitor, make the amplifier adjustments (e.g., bias) and then determine which setting of the voltage selector gives voltages closest to that specified in the schematic.
 
The tone board has been completely rebuilt with metal film resistors, C0G NP0 MLCC caps, Nichicon low leakage KL electrolytic caps, and WIMA metalized polyester film caps where possible. All-new Zener diode and transistors, especially the noisy 2SC871 devices replaced by KSC1845F devices.

IMG_8448.JPG IMG_8456.JPG IMG_8461.JPG
 
Great thread! And how timely! I had a 7000 given to me by a friend that was moving and had never used it. It was his fathers. Sat in his attached garage for about 20 years. I opened the case, vacuumed out all the dust and spider debris, and cleaned the face plate. Besides some oxidation on the Tape Monitor switches and noisy input selector when switching, and a few burnt out dial bulbs, it works perfectly. Amazing. I LOVE that it has two phono and two tape selects, and how the AM/FM dial and meters goes black unless you use the tuner. Independent L&R tone, and independent power button! Sweet bulb preservation! All pushbutton word caps are gone & the silver paint on the bezel needs a repaint, but other wise in perfect cosmetics. I printed some white ptouch labels on clear heavy duty labels. Fine for now.
 
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