Sanyo D314E replacement? Also transistors

[dennyj]

I am upgrading my Sansui TU 9900. There are two Sanyo D314E in the power section. I believe they are regulators or diodes. Anyone know a replacement? I can't seem to find info.

Also I want to replcace transistors C1312, A776 and C945. Any ideas?

Appreciate the help!
Denny

[Netlist]

Hi again, Denny.

Don't replace them if they work fine. Replace the caps.
You need a clean and steady +13V and -12.5V at the outputs. Here's the alignment procedure.

/Hugo

[Netlist]

And here's the schematic:

[dennyj]

Thank you! The 07 to 06 posts reading was good and I adjusted it to 13V.

But the 07 to 08 posts only read .8V. It's supposed to be -11.5 to -13.V. I'm thinking the D314E is bad on that side but don't really know how to test it. I tried the diode reading on my multi meter and one way is "over limit" where as the good side one reads 1.26 V. Both read .566V the other way. Do you have suggestions for replacement if it's bad??

BTW I have replaced the caps w/ Blackgate and Muse. I upped the 470 uf to 1000 uf but the rest I kept the same values.

Appreciate the help,
Denny

[Netlist]

On the schematic, you find parts marked TR, D, R and C
TR stands for transistor so TR01,02 stands for Transistor 01 and 02, in this case both 2SD314E. You recognize the abbreviate code D314E.
Transistors usually have three pins, Emitter, Base and Collector.
--| is base, pin with arrow is emitter, pin without arrow is collector.
In most circuits we find Positive nPn and Negative pNp transistors.
You can recognize them with the arrow, when it points outwards, the transistor is positive.
D stands for Diode, R for resistor and C for Capacitor.

Diodes have two pins, Anode and Cathode. --| is Cathode.
Resistors have no polarity and some capacitors like electrolytes have + and – as seen on most of them in the schematic.
Every time we measure voltage in this particular circuit we’ll do that with respect to ground which is pin 07 so your meters negative should stay connected to that pin.
All parts above the ground line serve the positive (+13V) part, all parts below the line are there to produce and regulate the negative voltage.
According to this, you should start looking at parts TR02, TR04 and TR06.
Here are some important values:
TR02:
B: -22.4V
E: -23V
C: screw of transistor: -13.4V

TR04:
B: -14V

TR06:
B: -0.6V
C: -14V

D04:
C: -18.8V

I’ve included the (flipped) layout for easy recognition of parts.

/Hugo

[Algar_emi]

Hi. I just bought the same tuner. In mine the supply was already repaired. TR01 and 02 were replaced by NT152, see http://www.nteinc.com/

Mine has a defective stereo indicator, I'll take the AM one and install a red led for the AM instead.

Check also these two sites:
http://www.antennaperformance.com/, mods section TU-9900

and this one in japan, but really good pictures of the restauration process: http://amp8.com/radio/tr-tuner/tu-9900.htm

I'm planning the following restaurations, mods:

Replace all supply eletrolytic with Panasonic FC,
Replace all Electrolytic in the audio path with BG
Replace 2 TA7136P op amps with OPA2604. I may build a small interface PCB to do so, want one?
Install IEC320 AC connector and shielded AC cable.
Replace feet with good EAR one, as use with Bel Canto gears.

I have all the test gears to fully retune it, so I'll do that also.

By the way do you have the user manual? I would like a good copy. Thanks in advance.

Bye...

SB

[Algar_emi]

And I was forgetting, replace the supply rectifier with discrete soft recovery diodes...