SX 850 - No Relay Click - Additional Question

Hello everyone! My Pioneer SX-850 is no longer getting the relay click, but all the lights still turn on. I accidentally left it on for about a week when I moved-in to my new place and when I came back, no relay click. :tears:

I've been reading up on threads here at Audiokarma for a few days now, (thank you to everyone has contributed!) and I recommend anyone else not getting a relay click to freshen up on the thread I link to below, specifically see MarkTheFixer's 2nd post:

http://www.audiokarma.org/forums/showthread.php?t=296800

However, I'm posting here because my multi-meter readings are a little different than everything I've read in other posts. I'm hoping someone can let me know if I'm barking up the wrong tree thinking replacing my transistors on the AWR-101 board (Q5, Q6, Q7) will fix things. It sounds like it's a good idea to replace them either way.

Here are my multimeter readings from my boards:
AWR-101:
2,3: 5.5v - OK (should be 5.4v)
4,5: 13.5v - OK (should be 13.9v)
6,7: 49.5v - OK (should be 51.5v)
8,9,10: 15v - BAD (should be 36.5v) <----I didn't find a post where someone had near 15v here.
11: 11.15v - BAD (should be 28v)
13: -13v - OK (should be -13.5v)
14: -50v - OK (should be -51.5v)
15: -18v - OK (should be -19v)
*Didn't measure any other pins.

AWM-062:
11: 15v - BAD (should be 36.5v)
2: -13v - OK (should be -13.6v)
12: 8.2v AC - OK (should be 7.5v AC)
* Didn't measure any other pins.

Q5 Transistor on AWR-101:
E - 15v - BAD (not sure of the target)
B - 15.75v - BAD (someone said this should be ~32v?)
C - 19.73v (someone said this should be ~42v?)
* I don't have the exact target voltage for these on-hand, but I think what I'm getting is way off.

So the main reason I'm posting is because in all the other cases where someone had problems with AWR-101 pins 8,9,10 (and as a result 11), they usually read 0v, not 15v. I'm definitely getting 15v. Could this still be a problem with Q5 or is there something else I should be testing? I ordered new transistors because they are cheap and I'll definitely update the thread with my progress.

Thank you, I really appreciate the help!

-Matt

one of two things has happened, and the Q5, Q7 readings will tell the tale.

Q5 is 36.5, while Q7 DEPENDS upon the 36.5v to make 28v.

Both are "proportional" regulators, the 36.5 depending upon the 51.5v being correct. The 28 depending upon the 36.5 being correct.

Assuming that, Q7 seems to be doing it's job (11/15 ~ 28/36.5)

Thus Q5 isn't delivering.

IF there is too much of a load on the 36.5v line, it can pull the q5 regulator down (because of R6, 150 ohms)

so measure the voltage across r6 (one dmm lead on each side at the same time ... NO ground involved in THIS reading), the load SHOULD be (45ma + 6.5ma + 4.5ma + 21ma) ~77ma and that gives about 12 volts (51.5 - 12 = 39.5v and q5 handles dropping the rest of the volts) across R6, so 15v out says (LOTS of calculations here) 250mA or so of current...

BUT check that R6 is not damaged, and is NOT more than 150 ohms with one leg out of circuit. (measure ohms with power off)

we can go into specifics of checking the current draws of the respective circuits.

NOW, with no relay click, the relay's 45ma is not flowing. that alters the calculation, but does not invalidate it.

Thus measure r6 voltage across it, and the e, b, c voltages of q5 referenced to ground. Then power off, lift an r6 leg and measure r6's ohms.
post the readings.

Hi Mark, I read a lot of your posts, you've saved a lot of pioneers!! It's great to get to work with you!

I've been labeling my transistor readings as if they were PNP, but they are actually NPN, right? I've edited this post and will edit my previous post to avoid confusing others.

Powered-up, R6 has 1.9v drop across it. (Additional info: 1 side of R6 reads 21.6v, the other side reads 19.7v)

Q5 had these readings powered-up:
E - 15v (emitter located on the side of pins 1-15)
C - 19.73v (collector being on the side of R6)
B - 15.6v (base being on the remaining side, opposite R6 side)

I then powered-down and removed a leg of R6. R6 measured 152 ohms across, which seems correct given the schematic I have.

Q7 had these readings powered-up:
E - 11.13v
C - 14.5v
B - 11.77v

Does this offer any clues?

Thank you

the one side closer to the row of pins on r6 should have the same voltage as pins 6 & 7 i.e. 49.5 volts

r6 is the correct value.

check that foil from q1 emitter to pins 6 & 7 then to R5 and then to R7, r7 and R3 at the end of the foil. Something's wrong...
That whole foil should be the equivalent of a wire connecting them all.

Ok, sorry I didn't figure this out sooner, but my readings have definitely changed since I took the initial readings.

AWR-101 Changed Readings:
6, 7: 21.5v
2, 3: 5.4v
4,5: 4.6

I'm confident they first measured what I wrote in the first post. My first readings were done before I took the board out of the plastic pegs and brought it out 90 degrees to make it easier to take the Q5 readings and remove the resistor leg. But I took the Q5 readings before removing the resistor let, so the issue must have happened before I removed the leg, which seems weird to me, because all I thought I did was re-position the board... maybe something else was close to breaking.

I need the q1 b,c,e and q3 e,c,b voltages. it is related to the awr-101 pins 6,7 and 4,5 voltages.

The pins 4,5 voltage uses the 14v zener reference from D11 in the +51.5v regulator.

I suspect the D11 voltage is about 5.2v instead of 14.6v.

Q1 it was hard for me to be certain of which is base, which is collector, and which is emitter, so bear with me if I get them in the wrong order.

Q1
C - 6.75v
E - 22.16v
B - 21.58v

Q3
C - 22.14v
E - 5.2v
B - 5.8v

I think my zener is labelled ZD1 on my schematic, not D11, it's right by the emitter leg of Q3, right? It measures exactly 5.2v, ha!

Right, q3 emitter.

512-1N5244B Fairchild 14 V, 0.5W Zener


Different labels, in big schematic and board level schematic... sigh...

either that diode got zorched or it's the wrong one.

The transistor voltages seem to indicate nothing major is wrong with them,



oh, please don't use a - as a separator, = works better....

- 22.14v positive, or -22.14v negative.. lol...

this time, it isn't critical.

Whoops, yea the dash could cause confusion. All of my measurements were positive, as you guessed.

My parts came this morning, which means I have a 1N5244B (among other things). I live about an hour away from Digikey, so the shipments get here the next day

I'm going to see if I can get the zenner replaced, but it might not be until tomorrow evening. We'll see how things go tonight.

So ZD1 was bad. After replacing it, I found I had 50.6v on pins 6 and 7 again. I noticed I still didn't get a relay click, so I moved on to measuring all the pins again. This time everything was giving a voltage that was in spec. Even 8,9,10 were at 36.2v.

...But like I said, no relay click. So then I figured I'd move on to measuring the transistors again, Q5, etc. I measure the emitter of Q5 at ~14v so then immediately move to check 8,9,10, which are now back at ~15v. !!

Luckily, pins 6 and 7 are still at 50.6, so I think my new zenner is still doing ok (I still have 2 more new ones, just in case). But something is still fishy.

I do have the complete set of replacements parts for the board (AWR-101). Should I just replace all of them? The only thing holding me back is I'd hate to introduce a new problem.

You have the parts replace them. Q5 is a problematic transistor in many 850-950 units. It is undersized for the job. The KSC2690 is a robust replacement that will far outlast the original. There are two Zeners that should be changed out also a 13V and a 14V, don't mix them up I've done that before. The board is easy to work on once you loosen all the wires from their harness and prop it upward. Replacing everything will give you peace of mind for years to come.

since the power supply is still apparently misbehaving, yes. Q5 and Q7 iiac...

first post q5 and q7 voltage readings, as well as R6 voltage across and ground referenced on each end. again.... looking to see what's up before risking NEW parts.

tsd71, thank you for the notes. I checked and I have both the 13v and 14v zenner (x3) with my new parts. I'll make sure to keep track of which is which. I also have some KSC2690s. I'd been wondering if others take the whole board off or just do replacements while the board is still mounted--it's good to know what I'm doing is ok. So far I've done all the work with it mounted (wires pulled out of the harnesses, etc) so I can get quick responses back, but I already numbered all my wires just in case I take the whole thing out to replace everything.

Mark, I have the readings, this time things are different, and I'm hoping it points to a bad R6 or Q5:

Q5
E: 50.8v
B: 36.3v
C: 14.5v

R6 Drop Across: 4.28v
R6 Legs to ground: 50.2v, 46.3v

Q7
E: 27.5v
B: 28.2v
C: 34.6v

Earlier you said R6 should be dropping ~12v. This time I see the input is correct, but not the output. Leading me to think R6 is for sure bad or not mounted well. Q5 I'm less sure of. Replace R6 and post new results? Oh wait, it seems I didn't order any replacement resistors :tears:. I might be out of luck until Monday, unless DigiKey pulls a miracle.

Keep it connected to the harness. It can be a pain but you must endure. Never mess with the wire wraps unless there is no other alternative. I have never repaired a 850 before but on the 950's I was able to remove the heat-sink (Outputs and STV's) and bring the whole amp board through the hole in the chassis. Now it was on the bottom of the set where the set was on back and the whole board was accessible. NICE. The only bad thing is; you can't do any troubleshooting.

Great to know about leaving it connected! Thank you!

I put a new Q5 in. If it breaks, I have more. I also re-seated R6 because my first solder job sucked and my new Weller came today, which makes things much easier. There is still no relay click (or sound output), so we're still on the hunt.

My Q5 readings I posted in my last post seem wonky (C and E), so maybe I did them wrong?? Anyway, here are the new readings AFTER a new Q5 and R6 re-seat. I still think R6 has to be replaced. DigiKey shipped my order, so I bet I get it tomorrow.

Q5:
C: 46.1v
E: 36.8v
B: 36.2v

R6:
Leg 1: 50.2v
Leg 2: 46.3v
Drop: 3.9v
In a previous post Mark said this voltage drop should be ~12v, so I suspect R6 has failed.

But just in case, here is Q7:
C: 34.7v
E: 27.6v
B: 28.3v

I also noticed my Q2 is a green transistor and Q1 is black. The green seems out of place, so I was thinking maybe it was aftermarket, but maybe not. My dad has an SX-850 and I always wanted my own. I finally got this one about 3 months ago from someone on eBay. It was their fathers and it came in the original Pioneer box. He kept good care of it, but I don't know the service history.

Hey, we are still working on the Power Supply. OK I am on the same page.

It looks like you should have all the power supply voltages up to speed.
Am I correct?

If so; check the protection board and take DC (See notes) readings on pins 1 through 12.
Note: Pin 4 is a ground to chassis. Check for continuity to chassis.
Note: Pin 12 is AC voltage 7.4vac or so.

Update: So by accident I left the receiver on again, but upon turning it off I heard the beautiful snap that only happens when shutting down AND the relay is clicked.

It's working again! But I didn't do anything, so we still have a flaky component here somewhere. The only measurements that have changed since my last post are:

R6 is now dropping from 50.2v to 40.7v. (9.5v drop)
Q5 Collector is now at 40.7v.

Does this mean I'm one R6 replacement away from a stable receiver? That's the impression I'm getting, but I wouldn't be any closer to an answer without all the help from Mark. Thank you!

I think you got crossed up in the repair and just overlooked the relay working. Once you got the PS operational it all fell into place. :scratch2:

I'd agree, except it's still intermittent at this point. I let some tunes play for a little while and after about 5 minutes it had cut out again and R6 was back to measuring only a 4v drop:

R6 Leg1: 50v
R6 Leg2: 46v
Drop Across R6: 4V

I'm going to wait until my new resistors get here tomorrow before doing much else, I don't want to break another component while things are flaky.