Hi, I know this is a bit of a long shot, but I could use some help on where to start looking for issues so I'm hoping someone may have a guess based on ...very little information.
I have a pioneer d23 active crossover driving 3 way active. A few months ago I replaced all the electrolytics in a successful attempt to repair an issue. I've been using it without issue since then until last night I went to listen to music and got some mild volume from one driver only, everything else silent. After fiddling around a bit I now have no sound from any drivers. It's definitely in the crossover as preamp directly to driver amplifiers works fine.
I'm completely at a loss as to where to start. Powers on fine. I can't see any physical issues. I assume it can't be in any of the individual crossover boards or the whole thing wouldn't just not produce sound at once...
So I know it's not much info but I'm just hoping someone might be able to eat "it's probably xxx" or "check continuity on yyyy" because I'm unskilled and baffled
I Have a copy of the schematic but hifi engine seems to be down for a web version.
There is a version here that requires a few steps...
https://elektrotanya.com/pioneer_d-23.pdf/download.html
Tia for any advice or thoughts
I have a pioneer d23 active crossover driving 3 way active. A few months ago I replaced all the electrolytics in a successful attempt to repair an issue. I've been using it without issue since then until last night I went to listen to music and got some mild volume from one driver only, everything else silent. After fiddling around a bit I now have no sound from any drivers. It's definitely in the crossover as preamp directly to driver amplifiers works fine.
I'm completely at a loss as to where to start. Powers on fine. I can't see any physical issues. I assume it can't be in any of the individual crossover boards or the whole thing wouldn't just not produce sound at once...
So I know it's not much info but I'm just hoping someone might be able to eat "it's probably xxx" or "check continuity on yyyy" because I'm unskilled and baffled
I Have a copy of the schematic but hifi engine seems to be down for a web version.
There is a version here that requires a few steps...
https://elektrotanya.com/pioneer_d-23.pdf/download.html
Tia for any advice or thoughts
First rule of faultfinding is to check all the power rails are correct.
Make sure the relays are operating correctly. The power supply for those isn't easy to follow and some of the coils are in series so make sure the coils are energised.
Make sure the relays are operating correctly. The power supply for those isn't easy to follow and some of the coils are in series so make sure the coils are energised.
Thank you so much for helping.
So on the b1/b2 and -b1/b2 instead of 25v and -21v I got 30.7 across all of them.
I don't know if I'm measuring how I should be...
At 49/50 instead of 45 and -45 I get 61 and 67.4.
Im still looking for the relays physically which seems to be ... surprisingly difficult.
Do these readings mean anything to you? I'm googling as I can and trying to learn...
So on the b1/b2 and -b1/b2 instead of 25v and -21v I got 30.7 across all of them.
I don't know if I'm measuring how I should be...
At 49/50 instead of 45 and -45 I get 61 and 67.4.
Im still looking for the relays physically which seems to be ... surprisingly difficult.
Do these readings mean anything to you? I'm googling as I can and trying to learn...
All readings are measured from ground. Begin by measuring from the power supply ground to eliminate any broken or floating ground possibilities.
The +25 and -21 volt rails should be very close to the marked values as these are Zener regulated supplies. The polarity is important.
The +46 and -46 volt rails are unregulated and could well be a bit higher, particularly if unloaded (relays not powered).
The +25 and -21 volt rails should be very close to the marked values as these are Zener regulated supplies. The polarity is important.
The +46 and -46 volt rails are unregulated and could well be a bit higher, particularly if unloaded (relays not powered).
So I realized I was misreading the hand written schematic and it's supposed to be +29 not +25
So I made sure I was grounded effectively (I'm almost positive) and got.
30.5 (29 expected)
22.5 (-21)
That seems close to me?
For 49 and 50 it remains 65 range (45 expected)
I'm working on getting accurate readings for the relays, haven't measured them before and the readings aren't making sense to me so far... All make the expected "click"
My understanding is, if one relay goes bad it will cause the mute circuit for all outputs to not disengage, causing everything to be muted?
So I made sure I was grounded effectively (I'm almost positive) and got.
30.5 (29 expected)
22.5 (-21)
That seems close to me?
For 49 and 50 it remains 65 range (45 expected)
I'm working on getting accurate readings for the relays, haven't measured them before and the readings aren't making sense to me so far... All make the expected "click"
My understanding is, if one relay goes bad it will cause the mute circuit for all outputs to not disengage, causing everything to be muted?
Ah, so, interesting to me - I can open the relays while music is playing and get music. For 2 of the 4 relays.
They all measure the same - 24 ohm when energized.
So....relays...seem to be the issue, yes? Makes sense on a 50+ year old item.
They all measure the same - 24 ohm when energized.
So....relays...seem to be the issue, yes? Makes sense on a 50+ year old item.
If the relays click they are powered, well at least one set are. That doesn't mean the contacts are good though.
The circuit is messy to follow but this shows it much clearer.
The four relays are split into two pairs and the coils are in series. The high voltage (the ones shown as - and + 46 volts) are applied to pins 1 and 2 and pins 12 and 13.
You should see 46 volts (or higher) across D2 and a similar voltage across D1. Measure across the diodes and not to them.
The circuit is messy to follow but this shows it much clearer.
The four relays are split into two pairs and the coils are in series. The high voltage (the ones shown as - and + 46 volts) are applied to pins 1 and 2 and pins 12 and 13.
You should see 46 volts (or higher) across D2 and a similar voltage across D1. Measure across the diodes and not to them.
You can only measure the resistance with them isolated. I would expect around 1k or more for each. 24 ohms would be far to low and draw to much current... the power supply couldn't do that. Each relay coil should drop equal voltage across it. If you 65 volts across pins 1 and 2 then each coil of that pair should have around 32 volts across it.
Very much appreciate your continued assistance. This is something I would tend to take to a tech but I'm really trying to learn and also really trying to not be without music for over a month...
How to measure that incoming voltage across the diodes was the question I didn't know how to ask exactly, but what I wanted to find out.
Yeah I didn't think the 24ohms made sense...
In theory a relay can be bypassed. Is that true in the context of this circuit with its relatively complicated mute circuit?
I am able to close one relay and get sound from the mid/high output, but the same procedure doesn't work for the midbass/low outputs....
How to measure that incoming voltage across the diodes was the question I didn't know how to ask exactly, but what I wanted to find out.
Yeah I didn't think the 24ohms made sense...
In theory a relay can be bypassed. Is that true in the context of this circuit with its relatively complicated mute circuit?
I am able to close one relay and get sound from the mid/high output, but the same procedure doesn't work for the midbass/low outputs....
If you have the voltage then the relays should be energised. Simple confirmation of that is to measure the voltage across each coil which will be half the total of the applied voltage. Also the relays should get a little warm after a few minutes.
Further confirmation for continuity of the contacts is to measure (using ohms on the meter) from input to output.
Look at the relay diagram. So from pin 18 to pin 23 you should read 240 ohms (the value of R9). Repeat for all relays e.g pin 16 to 24 and 9 to 25 and so on). There are eight reading in all.
If all that is OK then the relays would seem to be in order and working.
Very good observation. Might be worth looking at the raw -/+52 volt supplies here and checking they are not excessive. I see it has a voltage selector so make sure that is set correctly:
Strangely the voltage selector is drawn with 5 steps, while the transformer only has 4 taps, most likely 110,120, 220, 240. Nowadays I always select 240V for the 230V grid on older equipment, especially when on sunny days the grid voltage can be a lot higher than that, up to 253V here in the EU.
So there isn't actually a voltage selector on the unit, my guess is those are just the options from factory....unless it's somewhere I have never come across as I've been through the thing.
Those caps are still rated at 50v. I'm very confident (but never 100%) on the polarity.
I can't for the life of me get a good reading that makes sense across the relays, but from the pins to output I got (and I triple checked them all)
18-23 = 1
16-24 = 1
9-25 = 20ohm
7-26 = -420
All the rest are -420
As far as measuring the -/+ 52, my guess was to measure from ground to pins 44 and 45 but I got no results there...
I feel like I'm getting more baffled as I go along 🙂
Does it make any sense for the 9 and 7 to have different readings on the same relay? Maybe the 20 was a measurement error but I kept getting it.
Would seem r1 is not functioning ...and it's in series with r2...
What do these -420 readings indicate, when 240 is expected?
Any further thoughts is so appreciated, for real
Those caps are still rated at 50v. I'm very confident (but never 100%) on the polarity.
I can't for the life of me get a good reading that makes sense across the relays, but from the pins to output I got (and I triple checked them all)
18-23 = 1
16-24 = 1
9-25 = 20ohm
7-26 = -420
All the rest are -420
As far as measuring the -/+ 52, my guess was to measure from ground to pins 44 and 45 but I got no results there...
I feel like I'm getting more baffled as I go along 🙂
Does it make any sense for the 9 and 7 to have different readings on the same relay? Maybe the 20 was a measurement error but I kept getting it.
Would seem r1 is not functioning ...and it's in series with r2...
What do these -420 readings indicate, when 240 is expected?
Any further thoughts is so appreciated, for real
You need to be logical and if something is as expected then concentrate on that one issue and find out why.
You should be measuring the rectified DC on the output side of the bridge (from ground).
You are reading from the output socket which is point 23 (and with nothing connected to the socket) to pin 18. If it doesn't read 240 ohm then find out why 🙂 See what resistor value is fitted. Check continuity up to the relay and so on.
Nope 😉 That is AC at that point and would be around 37 volts AC.
You should be measuring the rectified DC on the output side of the bridge (from ground).
If the diagram is correct it should read 240 ohm (the value of those series resistors in the audio path) but only when the relay is closed (powered up). All should be identical.
You are reading from the output socket which is point 23 (and with nothing connected to the socket) to pin 18. If it doesn't read 240 ohm then find out why 🙂 See what resistor value is fitted. Check continuity up to the relay and so on.
That is what you have to find out.
So recheck the voltages. If you have 65 volts across pins 12 and 13 which feed the relay then you should see half that voltage if you measure across each relay coil. If that is not happening then you have to why. Its a series circuit of two relay coils which will have identical coil resistance and so they split the voltage automatically across themselves.
Appreciate your comment to think logically. Its important reminder for the newbie. I followed the paths and always needed up getting wonky at the relays. So I shunted all the relays and everything works dandy.
I may just leave them out as I get no on/off noise and I will turn on before amps.
Still a bit bothered by the 64 volts when there should be 46 or 52. I suppose at the least I could up size those caps from 50v, but I wonder what's causing it.
Thanks so much again, listening to music again 🙂
I may just leave them out as I get no on/off noise and I will turn on before amps.
Still a bit bothered by the 64 volts when there should be 46 or 52. I suppose at the least I could up size those caps from 50v, but I wonder what's causing it.
Thanks so much again, listening to music again 🙂
Relay contacts are notorious for giving problems as they age. The signal currents are so small they can not 'self clean' and burn any contamination off and so if linking them out has fixed the problems then it sounds like that is what is happening.
The 64 volts question does need looking into. If the caps really are 50 volt rated and there is 64 volts across them (check first by measurement) then it sounds more than amything that the mains input voltage is higher than specified for that unit. It would be like running a 100 volt rated unit on 120 volts, all the secondary voltages will be to high.
The 64 volts question does need looking into. If the caps really are 50 volt rated and there is 64 volts across them (check first by measurement) then it sounds more than amything that the mains input voltage is higher than specified for that unit. It would be like running a 100 volt rated unit on 120 volts, all the secondary voltages will be to high.