View Full Version : Sansui G-7500 - Help


solex
01-10-2012, 11:29 AM
Hi All,
I'm new the forum and just picked up a Sansui G-7500 it needs a volume know but more importantly it has a blown power fuse.

I have read the threads here on this common problem but will need some hand holding. Unfortunately I did replace the fuse 7AMP/250V and turned on the receiver and on of the 4 transistor smoked (no flames) and it looked like one of the pots as well.

Please let me know where to go from here, I would really like to fix this myself as the receiver as a whole is in excellent physical condition.

Regards,
Dan

cademan
01-10-2012, 07:55 PM
Welcome! Most of the time when a fuse blows, its due to a bad or shorted output transistor.

What is your level of expertise? Do you own a volt/ohm meter?

If you know how to check the output transistors, check them first, then the driver transistors.

If you can, give us pic so others may see or spot trouble areas to help you out.

petehall347
01-10-2012, 08:03 PM
look up "dim bulb tester" .it will save the equipment your time and money ...

solex
01-10-2012, 10:02 PM
Hi thank you all for the responses, I will look up the dim light-bulb tool.

I attached some images and did a quick diode check on the transistors that I had access to (the ones covered by the metal shield) and recorded that all but one passed the diode check.

I assume that I also have to check the output transistors as well, although I would like to take them out without having to unsolder a lot of wires.

Where else should I look? Although not terribly important are there any sources for a volume knob.

I'm excited to see if I can get this piece working.

solex
01-16-2012, 07:52 PM
I have order a better soldering iron and an solder vacuum hopefully this week I will start puling the transistors and ordering new ones when I get them all out.

I also order a G-5500 knob, I measured my existing tuning knob and it appears to be identical.

SSBN 618
01-16-2012, 08:14 PM
If you need a G-7500 schemetic, let me know.

solex
01-16-2012, 08:19 PM
Thanks I pulled them off the Internet, can't wait to dig in...