Sansui 990DB AM/FM no sound Help Help!

[PooPoo]

Is the ground suppose to be soldered?

 

[DougBrewster]

on my units it's a small spade connector so the tuner tray can be lifted off without the need for any de-soldering.

 

[PooPoo]

I'm not getting any voltage on pin 01. Any advice?

 

[Hyperion]

Pin 01 is the +12V output of the PSU, With your meter set to 'DC Volts' your black meter probe should go to chassis ground and your red meter probe should go to pin 01 (the +12v PSU output pin).

Be careful, take extra special care not to short anything out, 'meter probe slips' are common, we all do it from time to time.

Update
This post now updated with correct info.

Is the ground suppose to be soldered?

This bothers me a bit, if someone replaced the grounding method for that PSU, perhaps they didn't do it properly?.... which could mean that there is 12V output from the PSU, but only if you measure directly at the PSU PCB itself. (but not when measuring to a convenient chassis ground elsewhere).

 

[LBPete]

Did you check the power transistor mounted on heat sink? Pin 3 is the power supply for that board. What is the voltage between pin 3 and chassis ground? What is the voltage at the collector of TR01. What is the voltage at the base of TR02? These test voltages are called out on the schematic.

Also, please post the serial number for the database. Click on the link in my signature block.

- Pete

 

[PooPoo]

Did you check the power transistor mounted on heat sink? Pin 3 is the power supply for that board. What is the voltage between pin 3 and chassis ground? What is the voltage at the collector of TR01. What is the voltage at the base of TR02? These test voltages are called out on the schematic.

Also, please post the serial number for the database. Click on the link in my signature block.

- Pete

It was TR02 C1211 damn the only one I didn't check early on. But I took a C1211 from the RF power supply of my QRX-9001 and slapped it in the 990DB and it Fired right up with the FM and FM stereo light even working now

 

[tranguru]

I have had a D313 which tested ok on the DMM... but failed in the unit (Marantz 4400)
if you pulled it, then just replace it.can also be another xtor as long as same housing and specs are the same or higher (Vce, Ic, ..)

 

[naderpe]

I have also had that problem were D313 tested good out of circuit. Replaced it and all worked. Might have even been that very receiver...some 5 or 6 years ago.

 

[naderpe]

The wood case you have looks just like one I had...put it on many different units and finally left it with a restored 990db some years ago and let it go. I had a very difficult time letting that case go, took me a year or so to decide. Your 990db has the wrong Dolby knob so maybe it’s a different unit all together?

 

[PooPoo]

View attachment 922708 View attachment 922709 The wood case you have looks just like one I had...put it on many different units and finally left it with a restored 990db some years ago and let it go. I had a very difficult time letting that case go, took me a year or so to decide. Your 990db has the wrong Dolby knob so maybe it’s a different unit all together?

Yeah looks just like mines gorgeous

 

[PooPoo]

View attachment 922708 View attachment 922709 The wood case you have looks just like one I had...put it on many different units and finally left it with a restored 990db some years ago and let it go. I had a very difficult time letting that case go, took me a year or so to decide. Your 990db has the wrong Dolby knob so maybe it’s a different unit all together?

 

[LBPete]

The case looks like Santos Rosewood. Has it been re-veneered?

- Pete

 

[naderpe]

Yes re-veneered by AK member merrylander some 8 years ago.

 

[LBPete]

He does nice work.

- Pete