Leslie 860 power relay at startup

[andyhof]

I didn't notice this until yesterday, sometimes it takes up to 15 seconds for the Leslie 860 to power up after organ is powered.

Hammond XK-3 > 11 pin > leslie 860

Is this normal?

[David Anderson]

No, the 860 should power up pretty much instantly. The question would be whether the delay is in the 860 or in the XK-3.

The 860, like many 11-pin Leslies, has a control voltage circuit that's always-on whenever the Leslie is plugged in. As soon as the appropriate connector pins are shorted, the main AC power relay in the 860 should click on.

Now, is it normal for the XK-3 to behave that way? That I don't know off the top of my head.

[andyhof]

just tested again.

organ power up
wait for it..... wait for it... 15 seconds.... 860 powers up.

Power organ down.
860 immediately powers down.

Power organ up
860 powers up almost instantly



Let things sit for a couple minutes.....
Power organ up
15 seconds until 860 powers up

[Jyvoipabo]

Hello,

The 860 is remote controled by the XK3.

Everything indicates that in this circuit there is a capacitor that takes time to charge.
But when it is fully charged everything goes in order.

First, have look at the fuses of the 860, and in particular FZ1 (1 / 16A = 62mA Slow).
It is made of a very fine thread and it could be tired.

JP

[andyhof]

First, have look at the fuses of the 860, and in particular FZ1 (1 / 16A = 62mA Slow).
It is made of a very fine thread and it could be tired.

JP

I had a close look (attached). Things look ok.

So, maybe just swap the FZ1 fuse. Well, it seems to be impossible to remove from the copper winding holder.
and everytime i attempt a wiggle, the fuse below moves. These are not in fuse holders... rather, soldered
to the board. I also don't quite understand the "piggy-back" fuse. I only see FZ1, FZ2 and FZ3 on schematic.

I kinda feel handcuffed at this point.

[David Anderson]

To test whether the problem is in the 860 at all -- or in the XK3 -- you can manually jumper the pins on the 860's input plug that power it up, assuming you can read the chart on the schematic that shows which pins to short (Pin 5 to Pin 6). If it powers on instantly, you have your answer.

I wouldn't start messing around with the fuses unless I was sure one was causing trouble. Personally, I'd suspect the XK3 first.

The fuse you see soldered in parallel with another fuse is something you see frequently in quick & dirty repairs, especially if the person doing the repair doesn't have a pigtail fuse (one with axial leads) handy. Saves time desoldering the blown fuse.

[andyhof]

To test whether the problem is in the 860 at all -- or in the XK3 -- you can manually jumper the pins on the 860's input plug that power it up, assuming you can read the chart on the schematic that shows which pins to short (Pin 5 to Pin 6). If it powers on instantly, you have your answer.

I wouldn't start messing around with the fuses unless I was sure one was causing trouble. Personally, I'd suspect the XK3 first.

Thanks David. Before reading your reply I simply returned the power supply to the 860 and buttoned everything up. I’m not messing with what looks fine.

I will test this eve shorting pins 5-6 and reply with results.

[David Anderson]

One way to do it would be to jumper 5 & 6 with an alligator clip lead and have the 860 on a switched outlet strip, switched off. Then switch on the outlet strip, and see if it turns on instantly or not.

[andyhof]

Test1:

860 plugged into AC outlet.
short pins 5-6 on 860 with clip

takes about 15-20 seconds for 860 to power up.

Test2:
860 plugged into power strip with switch in OFF position
860 pins 5-6 shorted with clip
switch ON power strip

Same 15-20 seconds for 860 power up

[David Anderson]

Interesting and not what I was expecting.

The control circuit is composed of T2, D2, D3, and C1. Has C1 (250uF) been replaced?

Once the control circuit power supply is charged, shorting pins 5 & 6 draws current through the relay coil and 39Ω R1, turning on the mains power relay.

At this point, you might put a DC voltmeter across pins 5 & 6 (not shorted) with power strip off. Turn power strip on. See how long it takes for the voltage reading to come up to a maximum value.

I have seen one 11-pin Leslie where the mains power relay (REL 1 on schematic) was causing problems. Even though the control circuit was OK, it would stick. If you tapped the side of the power supply, it would switch on. No exact drop-in part is available for these power relays.

As JP suggests, maybe the 1/16th Amp fuse has developed high resistance. Seems a long shot to me, but worth measuring.

[andyhof]

Interesting and not what I was expecting.

The control circuit is composed of T2, D2, D3, and C1. Has C1 (250uF) been replaced?

Once the control circuit power supply is charged, shorting pins 5 & 6 draws current through the relay coil and 39Ω R1, turning on the mains power relay.

At this point, you might put a DC voltmeter across pins 5 & 6 (not shorted) with power strip off. Turn power strip on. See how long it takes for the voltage reading to come up to a maximum value.

I have seen one 11-pin Leslie where the mains power relay (REL 1 on schematic) was causing problems. Even though the control circuit was OK, it would stick. If you tapped the side of the power supply, it would switch on. No exact drop-in part is available for these power relays.

As JP suggests, maybe the 1/16th Amp fuse has developed high resistance. Seems a long shot to me, but worth measuring.

I did indeed replace C1 two years ago during the sizzle rebuild of the treble/bass amps.

well, ya ready for this?

I ran a continuity test on pin 6 all the way to S3/P3 while wiggling checking for cold solder.
Fine all the way thru.
Same with pin 5.

I then used some contact cleaner on the S3/P3 as well as the connector between the power supply and control board that sits on top of it.

Put it all back together. It now powers on immediately like new. Have done a few dozen power on cycles and it's fine now!

So possibly 42 years of oxidation on S3/P3 pin 6 and 2 was the culprit????

[David Anderson]

So possibly 42 years of oxidation on S3/P3 pin 6 and 2 was the culprit????

It can happen. I've found measurable resistance on the speaker connectors on older Leslie crossovers, and Molex connectors do not have a spotless reputation in this regard. I used to have a 1960s Pontiac that started stalling randomly, and it turned out to be a Molex connector on the car's firewall. I ended up having to hard-wire around it.

[andyhof]

Well after letting everything sit overnight....860 took 20 seconds to power up this AM. Came back to it a few hours later....powered right up. A little later it took 10 seconds. So I’m going to need to do a little more digging.

[andyhof]

At this point, you might put a DC voltmeter across pins 5 & 6 (not shorted) with power strip off. Turn power strip on. See how long it takes for the voltage reading to come up to a maximum value.

.

So if I measure DC across pins 5-6 at power up... we’re trying to rule out the relay as the problem? Such as, if DC voltage comes up immediately to maximum and the 860 does a delay start... we can focus on the relay at that point? And if DC takes time (15 seconds) to reach max, we could focus on fuses or the control circuit?

[David Anderson]

So if I measure DC across pins 5-6 at power up... we’re trying to rule out the relay as the problem? Such as, if DC voltage comes up immediately to maximum and the 860 does a delay start... we can focus on the relay at that point? And if DC takes time (15 seconds) to reach max, we could focus on fuses or the control circuit?

Pretty much. If no pins are shorted, there should be little current demand on the control circuit, except for some draw through the Zener portion of the motor control circuit.

With the whole thing powered off, you might also check the DC resistance of R1, the main power relay coil, and the Fuse FZ1.