Roland re201 echo

[pontiacpete]

I've been working on cleaning up one of these. It was in a room that was badly flooded but was told that it didn't go under water.
The problem so far is that the pinch roller does not move into place to move the tape when turning on.
I'm having a hard time understanding this circuit.
Does anyone have any suggestions where to start?
thanks

[Enzo]

Try moving it with your fingers, does it feel bound up? When I encounter old reel to reel tape decks, it is very common to find the lube has dried up and hardened, so the solenoid doesn't have the strength to move the pinch roller up into position. Disassemble, clean off the old lube with solvent, relube, reassemble, and it usually works.

Of course if the solenoid doesn;t get energized that would be a problem too.

If it is not mechanical, then look at the schematic. Page 4 block diagram shows a solenoid on the pinch roller. Page 6 wiring diagram shows the solenoid coil connected to posts 45,46 on the power supply board. (It also shows the level meter illumination wired between posts 44,46, more in a moment). Page 9 is the power supply board schematic. Posts 45,46 show the solenoid wired there, post 45 being the +15vDC. Note the meter illumination light is essentially parallel to the solenoid, post 44 being just a resistor off the +15. Note also that post 46 is just a tie point for the jack J6, Echo Cancel Footswitch. That jack has a shunt contact to complete the circuit. If that contact gets dirty, the solenoid can't work. SO either service the jack, or plug a stomp switch into it to turn the solenoid off and on.

Now about the meter lights. Since they are in parallel the solenoid, whenever the solenoid SHOULD be on, so should the meter lights. So: does the meter light up? If it does light, then the jack is probably OK.

[pontiacpete]

The roller can be moved by hand.
Does this mean the solenoid is not getting energized?
I cleaned the foot switch jack, the meter light is not working.
post 45 does not have +15, it's only 1.4vdc

[Enzo]

Probably, you tell me. There is either 15v across the coil or there is not.

Look at your schematic, page 9. The 15v supply is not grounded, so I have no idea what you might find on post 45 if measured to ground. The negative side of the 15v is post 49, also that is the sleeve side of the jack. Since the moitor also runs off the 15v supply, if the motor spins, you have 15v. Measure between post 45 and 49 for 15v. Measure between posts 45 and 46 for voltage across the coil.

Did you check the jack? With nothing plugged in, it SHOULD read a dead short from post 46 to 49. Does it? And if not, that right there will keep the pinch roller from pulling in.

[pontiacpete]

Ok , that was not the right reading.

Now I have:
17v between posts 45 and 49
and between 45 and 46

Between 46 and 49 I get a dead short .5 ohms

[Enzo]

So look at page 9. You have your 15v (17v is just as good, don't sweat the difference) between 45 46, so that leaves the wiring, the solenoid and the meter light. Either both the light bulb and the solenoid are open, or the wiring does not get the 15v to them.

[pontiacpete]

I will check all the connections and solder joints.

[pontiacpete]

Lifted one of the solenoid wires off the board and I get 102 ohms across the solenoid. Not open
It has the 15v across it .
I shorted the footswitch jack.
Pinch roller is still not moving into place.
hmmm

[Enzo]

It is either mechanical or electronic. If the pinch roller itself is free to move - ie you can push it up to the capstan easily with your fingers - then we have to look for electronics issues. The coil is not open. OK. Got a bench DC supply? Disconnect both wires from the board, clip them to a DC supply set for 12-15v. Does the solenoid pull in the linkage?

Anothe thing might be lack of continuity. Your meter light also does not light. Got continuity through the lamp?

Disconnect the lamp wires so it does not confuse things. Wire the solenoid back to 45 and 46. The coil measures 102 ohms, let's call it 100. Clip your meter black probe to 49, set for ohms. Power off. Now verify zero ohms over to anodes of D23, D24. Now verify zero ohms to post 46. Now verify 100 ohms to post 45. Now verify 100 ohms to the cathodes of D21, D22.

It is good that we have the individual parts good, but they are a whole circuit, and we need to know the whole circuit is acting as such.

[soundguruman]

I've been working on cleaning up one of these. It was in a room that was badly flooded but was told that it didn't go under water.
The problem so far is that the pinch roller does not move into place to move the tape when turning on.
I'm having a hard time understanding this circuit.
Does anyone have any suggestions where to start?
thanks

Seems like the foot switch jack, J 6, has a corroded or burned contacts inside. This prevents the solenoid from pulling in. You can bypass that contact by plugging in a foot switch.
Also the rectifier bridge, D 21,22,23,24 could go bad, or the winding of the PT that supplies it could be bad. (terminal 61,62)
The mechanical assembly can just be frozen, disassemble clean and lube...
But, it's usually just the footswitch jack contacts. The footswitch jack has 2 contacts inside, that go bad.(terminal 46,49) The ON OFF cycle of the solenoid burns those contacts out.
The more I think about it, the more I remember that's what fails. It's been a couple decades since I saw a working one. hahahahahahahah.

[pontiacpete]

Put the solenoid on a 15v power supply and it moves. )
Then I tried the footswitch jack again, this time grounding it from the inside of the unit, (duh!)
It works, so I need to replace the jack or clean it some more.
Thanks for helping me through this!!

[soundguruman]

Put the solenoid on a 15v power supply and it moves. )
Then I tried the footswitch jack again, this time grounding it from the inside of the unit, (duh!)
It works, so I need to replace the jack or clean it some more.
Thanks for helping me through this!!

The FS jack contacts burn out from the current draw. Needs a new jack for sure.

[Enzo]

Yeah, I can see how that huge 150ma would be burning up jacks...

[soundguruman]

Yeah, I can see how that huge 150ma would be burning up jacks...

Inductive reactance, the DC reluctance of the coil causes a major surge everytime it turns on.
The surge is only a few ms, but eventually the contacts fry.
Take it apart, there's carbon built up on the contacts...you can see it.
The contacts of the jacks were never designed to carry current. They were made for audio only.
Seen that happen a bunch of times on the space echo.

[Enzo]

That isn't carbon, it is dirt.

The contacts of the jacks were never designed to carry current. They were made for audio only.

So the countless numbers of Fender amps using the jacks for speaker connections must be just covered with carbon, considering that the speakers have several amperes running through, not 150ma.