• Please note that Audiokarma will be offline briefly for updates early on Monday morning, September 28th.

SX-D7000 won't power up

Bigears

Bigears

Manager of my own day
I picked up a cosmetically nice SX-D7000 originally for parts for my beater D7000, but this one is really too nice to part out.

Symptoms: will power up to the point of engaging soft start relay and that is it. No display lights, no function lights, no output. Dead otherwise. I have the SM pdf, but I'm a little unclear on what the correct votages are on the rectifier board (211), power supply board (216) and fuse board (217). Unlike the schematic on for my 1250, the voltages seem to be replaced with a letter system and so far I can't find the conversion anywhere in the SM.

Am I correct to start at the rectifier board first? Thanks!
 
Register to hide this ad
The voltages are on the schematic, you just have to look for them a bit.

The soft start relay activating means that everything up to the power supply regulators is ok, everything is working to the raw +70vdc to the 54v regulator, and conversely unless proven otherwise the -70v raw dc power to the -54v regulators, thus forget about the rectifier board (211) and fuse board (217) for now. (They're a bear to get to anyway, be glad you don't have to mess with them).

What about the tone lamps? And the speaker abc leds? They run off of the 8.6v supply. Do they light? That is an independent regulator.

The -54v regulator depends upon the +54v regulator working to turn it on.

The +54v regulator AND the +12v regulator depend upon D6, the 14v zener diode in the positive 54v regulator. There is a cap C9 across the zener that could short, then a 100 ohm resistor R21 and a cap C19 across the zener at the 12v regulator. Also Q9 could mess the zener reference voltage up....

You need to start reading the voltages at the pins of the regulator board.

Is it parallel to and behind the front panel, nearly inaccessible??
 
markthefixer said:
The voltages are on the schematic, you just have to look for them a bit.

The soft start relay activating means that everything up to the power supply regulators are passing power, thus forget about the rectifier board (211) and fuse board (217) for now.

What about the tone lamps? And the speaker abc leds? They run off of the 8.6v supply. Do they light? That is an independent regulator.
Click to expand...

No lights at all. Dark at the faceplate.


markthefixer said:
The -54v regulator depends upon the +54v regulator working to turn it on.

The +54v regulator AND the +12v regulator depend upon D6, the 14v zener diode in the positive 54v regulator. There is a cap C9 across the zener that could short, then a 100 ohm resistor R21 and a cap C19 across the zener at the 12v regulator. Also Q9 could mess the zener reference voltage up....

You ned to start reading the voltages at the pins of the regulator board.

Is it parallel to and behind the front panel, nearly inaccessible??
Click to expand...

Okay if we are talking about AWR 216 (see pic), here is what I found. I still can't find the voltage conversions. I downloaded the SM from the AK archives. Sorry about the list format
1. 24v
2. 0
3. 90v
4. 0
5. 0
6. 6v
7. 18v
8. 0
9. 0
10. 0
11. 0
12. 30v
13. 18v
14. 18v
15. 0
16. 0
17. 60v
18. 60v
19. 60v
20. 0
21. 4.3v
22. 0
23. 0
24. 2.8v
25. 0
26. 0
27. 0
28. 0
29. 0
30. 54v
 

Attachments

  • AWR216 (Medium).JPG
    AWR216 (Medium).JPG
    126.7 KB · Views: 85
SXd7000 AWR216 power supply pin voltages

SXd7000 AWR216 power supply pin designations and voltages

OK, I dug EVERYTHING out of the SAME .PDF you have, unless it is indicated IN somewhere, it is an OUT...

pin ... you ..... should be
1 ..... 24v ..... 120VAC LINE PLUG in UNSWITCHED for xfmr for memory keep alive
2 ..... 0 ........ x
3 ..... 90v ..... 120VAC LINE PLUG in UNSWITCHED for xfmr for memory keep alive
4 ..... 0 ........ GND (ret for soft start relay)
5 ..... 0 ........ +8v raw dc memory keep alive for digital circuits.
6 ..... 6v ...... +25v protection circuit power on signal - low current
7 ..... 18v ..... in CT, violet of blue pair t2 xfmt winding
8 ..... 0 ........ x
9 ..... 0 ........ x
10 ..... 0 ...... +8.6v reg
11 ..... 0 ...... +8.6v reg
12 ..... 30v ... +27 to 30v raw dc (+24) to tuner's pa4006 chip
13 ..... 18v ... FU4 to t2 blue AC in
14 ..... 18v ... FU3 to t2 (other) blue AC in
15 ..... 0 ...... GND
16 ..... 0 ...... GND to power indicator board's transformer
17 ..... 60v ... FU2 to t2 yellow AC in (brown CT is grounded)
18 ..... 60v ... FU1 to t2 orange AC in (brown CT is grounded)
19 ..... 60v .. FU2 yellow AC OUT to power indicator board's transformer
20 ..... 0 .... +13v reg
21 ..... 4.3v -54v reg
22 ..... 0 ..... gnd
23 ..... 0 ..... gnd
24 ..... 2.8v . +54v reg
25 ..... 0 ..... +32v reg
26 ..... 0 ..... +32v reg
27 ..... 0 ..... -32v reg
28 ..... 0 ..... -32v reg
29 ..... 0 ..... -21v reg (-32vreg - D13Vz(11) = -21v reg)
30 ..... 54v .. +70v through 1.5k resistor, 54v looks ok, soft start relay

The most puzzling thing is the missing 8.6v on pins 10 & 11. Because pin 12 shows (tuner 24v) voltage that feeds that regulator. The 12v could be shut down by a bad reference, but pin 7 violet (CT) wire is unfused, so the possibility of FU3 being blown exists, as part of a full wave rectifier charge pump that establishes the floating -13v at chassis ground potential.
 
Okay, thanks Mark. I guess I need to blow up the schematic and look a little harder. Is my next step testing the board mounted components on the power supply?

Edit: I did confirm no power at pins 10 and 11.
 
The easiest thing to do is a rebuild, with known good parts. Doing it yourself will keep the parts cost down. We are talking transistors, diodes and caps.

Considering the work necessary to get to the board, and the danger of operating the board in a precarious position to get measurements, as well as the disassembly & reconnection to get the measurements in the test position, your best chance of success is to shotgun the board with known good parts. The largest investment will be doing the caps, and those have a fixed lifespan that makes replacing them a good idea (rather than figuring out which is bad, then waiting for the next one to fail sometime in the foreseeable future ) while it's open. Then we have just $0.16 of diodes and $3.20 of power transistors, some of which do have problems.

I would be surprised if parts costs were over 15 bucks. The fly in the ointment is that the Q1 & Q2 2sk34 jfets are getting harder to find, as they are a 50v jfet.
I am working on replacements (current regulating diodes ~ 2 bucks each, 100v), but anticipating the cutoff of that replacement part at mouser (ksk30) I got a bunch. Ampslabs also has (?) them, but they only sell 20 at 20 bucks (last time i looked).

I have to check and see if I have already posted a parts list under sx-3800, sx-3900, sx-d5000 or sx-d7000.

edit: working on the list, looks like 14.59 w/o shipping or the two 2sk34's.
 
Mark, good advice on rebuilding the power supply board. Much like the power stabilizer board on my SX 1250, this looks like a high failure component at this age and I want to fix this thing once. I'm competent at soldering and PCB component replacement, so shotgun it is.

I have another "beater" D7000 that is functional, and I can see that the smaller caps on the power board have outgrown their wrappers. I may just do both boards at once. I'm also considering parting the beater since the faceplate is pretty banged.

I truly appreciate a parts list for this board. For me, the most difficult part of this process is finding subs.
 
sxd7000 awr216 power supply parts

sx-d7000 awr216 power supply parts..... messy but complete

mouser.com parts numbers
nichicon upw caps, fairchild transistors, I.C. and diodes
cap uf spec v real v part number each subtotal
c3,4 220 80 100 647-UPW2A221MHD 1.26 2.52
c10,11 47 63 100 647-UPW2A470MPD 0.48 0.96
c23 10 63 100 647-UPW2A100MED 0.25 0.25
c12,13 47 50 50 647-UPW1H470MED 0.25 0.5
c16 10 50 50 647-UPW1H100MDD 0.16 0.16
c5 2.2 50 50 647-UPW1H2R2MDD 0.14 0.14
c18 1000 35 50 647-UPW1H102MHD 1.26 1.26
c17 100 35 50 647-UPW1H101MPD 0.36 0.36
c20 100 35 50 647-UPW1H101MPD 0.36 0.36
c9 100 25 50 647-UPW1H101MPD 0.36 0.36
c19 100 25 50 647-UPW1H101MPD 0.36 0.36
c15 2200 16 35 647-UPW1V222MHD6 1.71 1.71
c22 220 16 35 647-UPW1V221MPD 0.41 0.41
c2 3300 10 25 647-UPW1E332MHD6 1.33 1.33
c21 470 10 25 647-UPW1E471MPD6 0.55 0.55



d6 512-1N5244B 0.05
d13 512-1N5244B 0.05
d12 512-1N4148 0.03
d14 512-1N4148 0.03

q5 512-KSA910YBU 0.12
q4 512-KSC2310YBU 0.12
q6 512-KSA940TU_Q 0.54
q8 512-KSA940TU_Q 0.54
q3 512-KSC2073TU 0.54
q7 512-KSC2073TU 0.54
q9 512-KSC2073TU 0.54

q10 512-LM7808CT 0.26


rough total at posting time: 14.59

q1 & q2 are 2sk34 jfets (50v) set up as constant current sources. either 2 current regulator diodes can be used at about 100v max for ~2.00 each
or
2sk30a-y jfets from ampslab.com.(20 for $20 at last check)

I have a few too.
 
Mark, this is great info, thanks so much. I won't get to for a while, but I will follow up with an update once I complete the board repair. Excellent!
 
Bigears said:
I don't think thread will help Darren, he's got driver board issues with his D7000
Click to expand...

That was over a year ago, and I have heard nothing since.... did he find anything??? I was ready to get going with that one, and then ......... nothing .....
 
markthefixer said:
That was over a year ago, and I have heard nothing since.... did he find anything??? I was ready to get going with that one, and then ......... nothing .....
Click to expand...


Nothing turned out to be that I got bit with the Sansui bug. :D Have patience, Mark. I'll resurrect the thread once I'm done with my G-8000 herd. The D7000 is next in line after I finish reveneering two Sansui cabinets and repairing a F-2806driver board. Besides, I've been trying to cut my troubleshooting teeth a little bit more on smaller repairs before diving into the D7000 - it's just so damned tight in there I'm a bit intimidated.

I'll thank you in advance for your help...and your patience. Should be only a few more months, er, I mean weeks. :thmbsp:
 
Okay, about to remove the power supply from my dead D 7000 to rebuild it, but I'm stopped as I contemplate the best way to remove it and ensure that I wire it up correctly once its rebuilt. I took many color pics, hand wrote a schematic, (the wire colors repeat often!) and zip tied the paired wires to take some guesswork out of that aspect of this repair.

My plan was to unwrap the wires a few turns and snip them, soldering them back on to the clean pins. Is that the best way to do this?
 
Bigears said:
Okay, about to remove the power supply from my dead D 7000 to rebuild it, but I'm stopped as I contemplate the best way to remove it and ensure that I wire it up correctly once its rebuilt. I took many color pics, hand wrote a schematic, (the wire colors repeat often!) and zip tied the paired wires to take some guesswork out of that aspect of this repair.

My plan was to unwrap the wires a few turns and snip them, soldering them back on to the clean pins. Is that the best way to do this?
Click to expand...

No unwrapping, I haven't taken off a d7000 panel, but have done 3900's. When there is absolutely NO choice I desolder the pin from the board, leaving the wrap ALONE.

There is nothing wired to the sides or bottom, it has to come straight up out of it's slot, and then rotate 180 or so using the pins axis as the rotation point.
 
markthefixer said:
No unwrapping, I haven't taken off a d7000 panel, but have done 3900's. When there is absolutely NO choice I desolder the pin from the board, leaving the wrap ALONE.

There is nothing wired to the sides or bottom, it has to come straight up out of it's slot, and then rotate 180 or so using the pins axis as the rotation point.
Click to expand...


Man I'm glad I asked. Of course this is the right way to remove the board wires. Thanks!

Removed two screws and the board is top side as much as the wiring allows. Ready to desolder.
 
Bigears said:
Man I'm glad I asked. Of course this is the right way to remove the board wires. Thanks!

Removed two screws and the board is top side as much as the wiring allows. Ready to desolder.
Click to expand...

Should be waving like a flag over the whole unit. Set the unit on it's side for better access, then it will be sticking out the side.
 
Pulled the board tonight. The wiring pins spacers and all came right out of the PCB using a small screwdriver to wedge between the nylon pin spacer and the PCB as I alternated heating the solder on the pins. Fairly easy going. Now to order up the parts.
 

Attachments

  • P1070797 (Medium).JPG
    P1070797 (Medium).JPG
    143.9 KB · Views: 84
Was wondering how progress went/or is going on your SX-D7000. The board you have pulled out is the same one I have issues with on one of my 7000s. I'm not brave enough to remove it yet.
 
You must log in or register to reply here.
Back
Top Bottom