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sx-650 relay not clicking

markthefixer said:
we gotta check the power supply regulators.

dmm black lead to bare meal chassis ground

probe with INSULATED (all but a minute portion of the tip of the probe) red dmm lead:

from the bottom of the chassis:
pin 29 (s/b 33v)
pin 28 (s/b -34v)

From the top of the chassis:
pin 35 (s/b 13v)


View attachment 2557114
Click to expand...
You’re the best.
Power amp 1 (horizontal board from below chassis):
Pin 29 (32.5V)
Pin 28 (-35.2V)

Power amp 2 (vertical board from top of chassis)
Pin 35 (13.1V)

looks correct to my untrained eyes
 
And no difference detectable in the speaker sound.


It continues unabated when the protect relay has dropped out / disconnected the speakers.
 
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markthefixer said:
And no difference detectable in the speaker sound.
Click to expand...
I’ll try to play with it again in the morning and see if I can notice anything remarkable at high volumes/when hiss is present. Thing is that when is comes out of protection mode it is cycling back in so fast it’s pretty hard to make an assessment on the sound. I’m also using chinesium dummy speakers so not the best critical listening speakers. During that short amount of time so far I’ve just thought it sounded fine. Nothing obviously wrong. But again, I will try to pay closer attention to that in the morning. Good night for tonight!
 
Let's see what is triggering the protection. Using subtractive troubleshooting.

Desoldering and lifting one leg of D7 (outlined in Blue) will suppress the over-current protect triggering.
You can hit the right spot from the solder side of the board, desolder the pad and push the lead through the hole to air gap it.
It won't stop the sizzling but it will silence THAT protect input.

The protection has two badly behaved capacitors in it, C21 and C22 (0.22uf 10v CSSA). they turn into short circuits. The dreaded sky blue Sanyo "capsistor",
whose electrical leakage gets so bad it turns into a short circuit.
Normally there are 2.7k ohm resistors between them and the power output sections, but if one of those resistors has fried to a short circuit, all bets are off.

The caps (2x 0.22uF /10v ) to replace are circled in red, the resistors to test (2.7k ohm) are circled in red

the rest to be tested is circled in orange:
(4) 15k resistors
(4) 1s2472 small glass diodes
(2) 2sc1649 transistors.

ignore R50 & R51 off at the side of the board, if the power had not been stable, we could have read the voltage across them to find out the current draw for the +13v and +33v power supplies.

The transistors could be replaced. ksc1845 is the usual if you have it.


upload_2022-5-3_23-8-53.png
 
Last edited:
markthefixer said:
Let's see what is triggering the protection. Using subtractive troubleshooting.

Desoldering and lifting one leg of D7 (outlined in Blue) will suppress the over-current protect triggering.
You can hit the right spot from the solder side of the board, desolder the pad and push the lead through the hole to air gap it.
It won't stop the sizzling but it will silence THAT protect input.

The protection has two badly behaved capacitors in it, C21 and C22 (0.22uf 10v CSSA). they turn into short circuits. The dreaded sky blue Sanyo "capsistor",
whose electrical leakage gets so bad it turns into a short circuit.
Normally there are 2.7k ohm resistors between them and the power output sections, but if one of those resistors has fried to a short circuit, all bets are off.

The caps (2x 0.22uF /10v ) to replace are circled in red, the resistors to test (2.7k ohm) are circled in red

the rest to be tested is circled in orange:
(4) 15k resistors
(4) 1s2472 small glass diodes
(2) 2sc1649 transistors.

ignore R50 & R51 off at the side of the board, if the power had not been stable, we could have read the voltage across them to find out the current draw for the +13v and +33v power supplies.

The transistors could be replaced. ksc1845 is the usual if you have it.


View attachment 2557267
Click to expand...
This will have to wait until tomorrow night or most likely Friday for me to test by desoldering that leg on D7. Alternatively I might just remove those Sanyo caps and test them. I have a cap tester so I can get an idea of if it’s drifted out of range or otherwise so I can at least rule out those. Based on other posts involving Sanyo caps, it may be best to preemptively replace them anyways.

What do you mean by “if those resistors are fried to a short circuit, all bets are off?” If you mean it is possible that further testing could or likely will damage other components I would prefer to just replace all these suspect components at once as opposed to the chance of further damage. I will defer to your guidance. Shotgun replacing things vs more troubleshooting. I don’t have these components on hand but I don’t mind a $30 order

Let me know your thoughts!
 
The "short circuit" remark was trying to understand how enough energy was getting to whatever is making the sizzling noise to MAKE the sizzling noise.

I feel that the 2700 ohms of those resistors limit the amount of energy available to those Sanyo caps
and their internal mayhem that presents as a short circuit.

Your cap tester may NOT test for leakage or it may have to be horrendously bad for it to sense it.
The question is not IF, but rather WHEN that capacitor (of that type - an aluminum based cap like a tantalum cap) dies.

My "thoughts"?
When I get down to the "hands and eyes mode" (as in "you are my hands and eyes" as I figure this out) and someone starts improvising off on tangents, they get left to their own consul.
Troubleshooting changes have potholes and pitfalls to be avoided,
and I know where all of them are or I wouldn't be directing those changes.

I will say that a sizzling component that is not glowing, or emitting smoke & flames is a rarity in my experiences.

I had hopes that the Removal of the Sanyo caps would cure the sizzling.
 
markthefixer said:
The "short circuit" remark was trying to understand how enough energy was getting to whatever is making the sizzling noise to MAKE the sizzling noise.

I feel that the 2700 ohms of those resistors limit the amount of energy available to those Sanyo caps
and their internal mayhem that presents as a short circuit.

Your cap tester may NOT test for leakage or it may have to be horrendously bad for it to sense it.
The question is not IF, but rather WHEN that capacitor (of that type - an aluminum based cap like a tantalum cap) dies.

My "thoughts"?
When I get down to the "hands and eyes mode" (as in "you are my hands and eyes" as I figure this out) and someone starts improvising off on tangents, they get left to their own consul.
Troubleshooting changes have potholes and pitfalls to be avoided,
and I know where all of them are or I wouldn't be directing those changes.

I will say that a sizzling component that is not glowing, or emitting smoke & flames is a rarity in my experiences.

I had hopes that the Removal of the Sanyo caps would cure the sizzling.
Click to expand...
Noted. So next step I will desolder D7 later tonight perhaps and update when I power on. I truly appreciate your help.
 
markthefixer said:
The "short circuit" remark was trying to understand how enough energy was getting to whatever is making the sizzling noise to MAKE the sizzling noise.

I feel that the 2700 ohms of those resistors limit the amount of energy available to those Sanyo caps
and their internal mayhem that presents as a short circuit.

Your cap tester may NOT test for leakage or it may have to be horrendously bad for it to sense it.
The question is not IF, but rather WHEN that capacitor (of that type - an aluminum based cap like a tantalum cap) dies.

My "thoughts"?
When I get down to the "hands and eyes mode" (as in "you are my hands and eyes" as I figure this out) and someone starts improvising off on tangents, they get left to their own consul.
Troubleshooting changes have potholes and pitfalls to be avoided,
and I know where all of them are or I wouldn't be directing those changes.

I will say that a sizzling component that is not glowing, or emitting smoke & flames is a rarity in my experiences.

I had hopes that the Removal of the Sanyo caps would cure the sizzling.
Click to expand...
Just wanted to update you that I haven’t forgotten about this. Work/life things have redirected my attention but I should be back at it later this weekend. Cheers!
 
markthefixer said:
Let's see what is triggering the protection. Using subtractive troubleshooting.

Desoldering and lifting one leg of D7 (outlined in Blue) will suppress the over-current protect triggering.
You can hit the right spot from the solder side of the board, desolder the pad and push the lead through the hole to air gap it.
It won't stop the sizzling but it will silence THAT protect input.

The protection has two badly behaved capacitors in it, C21 and C22 (0.22uf 10v CSSA). they turn into short circuits. The dreaded sky blue Sanyo "capsistor",
whose electrical leakage gets so bad it turns into a short circuit.
Normally there are 2.7k ohm resistors between them and the power output sections, but if one of those resistors has fried to a short circuit, all bets are off.

The caps (2x 0.22uF /10v ) to replace are circled in red, the resistors to test (2.7k ohm) are circled in red

the rest to be tested is circled in orange:
(4) 15k resistors
(4) 1s2472 small glass diodes
(2) 2sc1649 transistors.

ignore R50 & R51 off at the side of the board, if the power had not been stable, we could have read the voltage across them to find out the current draw for the +13v and +33v power supplies.

The transistors could be replaced. ksc1845 is the usual if you have it.


View attachment 2557267
Click to expand...
Ok so finally ready to tackle this again! Appreciate your patience. Before I desolder one leg out of D7 tonight and give it a go. Two questions:

1. To verify, does it matter which leg I desolder from D7?
2. To doubly verify, please look at this photo to verify I have identified D7 correctly. It is circled in yellow and surrounded by transistors.
 

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That IS D7. It does not matter which leg is desoldered, as long as there is an air gap between the diode and the pc board pattern.


and, I see the two Sanyo caps in the picture, plain as day...
 
markthefixer said:
That IS D7. It does not matter which leg is desoldered, as long as there is an air gap between the diode and the pc board pattern.


and, I see the two Sanyo caps in the picture, plain as day...
Click to expand...
Of course after it sitting for three weeks now I’ve turned it on and is working fine (relay clicked on power on and music is playing fine at least for 10 mins as of now). Might take me a few listening sessions to get it to misbehave like it was previously.
 
O
markthefixer said:
That IS D7. It does not matter which leg is desoldered, as long as there is an air gap between the diode and the pc board pattern.


and, I see the two Sanyo caps in the picture, plain as day...
Click to expand...
Ok finally got it to recur. Turned the volume up past 12 o’clock and got it in protection mode. Turned volume back down and it started cycling in and out again. So now I will proceed with desoldering one leg of D7. Might not be able to update til tonight.
 
markthefixer said:
That IS D7. It does not matter which leg is desoldered, as long as there is an air gap between the diode and the pc board pattern.


and, I see the two Sanyo caps in the picture, plain as day...
Click to expand...
Alright so with D7 desoldered I’ve been playing now for 30+ mins no issues even if I turn the volume past 12oclock. What does this mean exactly and what do I need to do next? Would you suggest I replace those Sanyo caps?

Sizzling still occurring on FM input past 12oclock.

what does it all mean!? My issue is likely the problem Sanyo caps in the protection circuit??
 
Last edited:
rcs16 said:
I would replace those Sanyo ecaps as suggested and go from there, use a film type with 5mm lead spacings
Click to expand...
Yeah I believe mark intended for me to replace those previously and I overlooked that somehow. I will await his response but I’m sure that’s my next move.
 
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