Revox PR99 remote control

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A revox PR99 has lost his remote control plug. It's needed when no remocon is used and plugged in the socket, making one or more bridges to make the recorder behave. Without plug, everything works fine except the play button has to be kept pressed. Could someone with knowledge of logic electronics find out what pins I have to bridge to fix this problem.
Schematic here.

/Hugo
 
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Ghianni
I found out, as Milan said that no plug is needed in the PR99.
Next thing I looked for was the ‘tape end sensor’ and I believe its working properly. Q10 stops conducting when the sensor light is interrupted. The 24V is 28V however. 5V is present.
There is no indication of tweaks inside.

Looking at the ‘fader start logic’ schematic, I assume K1 is activated when the ‘tape dump' button is pressed. In that condition, the play button stays active. FFW and REW don't work which is a perfectly normal condition.
I forgot to tell in my first post that FFW and REW don't stay put as well.
My lack of knowledge with ports and logic as used in the 'tape drive control' schematic prevents me from fixing that beauty.

/Hugo
 
Hi,
does it going into play mode without the tape present?
Is +24V present all the time at play signal line on the control board?
Can you stop machine from the play mode?

Netlist said:
My lack of knowledge with ports and logic as used in the 'tape drive control' schematic prevents me from fixing that beauty.
/Hugo [/B]

I have few old PRs for spares and can send you the critical boards for free. PM me if you are interested.

Regards,
Milan
 
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Hi Hugo,
Yes, the tantalums. I change them out for electrolytics. The dummy plug comment really threw me Hugo! I always forgot to put the A/B-77 plug back in while working on them. I couldn't recall the PR-99 with those memories rolling around. (ever stick the case back on with the dummy plug still in?)

Also, the bridge rectifiers tend to overheat. I have installed heatsinks on them in the past with thermal epoxy from Wakefield.

The PR-99 was one of my fav machines. Pretty too!

-Chris
 
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Chris,
Didn't notice your post till now.
That PR99 was in real bad condition. Had been standing for years in a moist area. The cost to repair that would be enormous.
The owner is a very caring pro but has no money to store his equipment in a decent garage and even less to pay repairs.
So I fixed what had to be fixed and let the rest alone.
Nice machine indeed.

/Hugo
 
I have similar trouble

Gentlemen,

A year ago, I bought used PR99 and I found something strange as below. I believe someone can explain what happens.

1. When I turn on power SW, it plays automatically regardress tape present. Is this normal?

2. 'PAUSE' butten only working when I holding it down while playing music. And playing again when I release it. Is this normal?

3. I could hear hum from monitoring speaker and it actually amplifying by turning volume when playing PR99 without tape set and I pretty sure it still humming when playing music but can't recongnize because of music. Strangely it's not appear from main speaker. Is someone have an experience about this?

Please give me any of your idea or cure.

Thank you in advance.


:bawling: :bawling: :bawling:
 
Re: I have similar trouble

chanwoo said:

1. When I turn on power SW, it plays automatically regardress tape present. Is this normal?

No, thats not right.


2. 'PAUSE' butten only working when I holding it down while playing music. And playing again when I release it. Is this normal?

Yes, that is how it's supposed to work.

3. I could hear hum from monitoring speaker and it actually amplifying by turning volume when playing PR99

Do you get hum from headphones too? If NOT, then its a fault in the monitor amplifier - probably a lose ground connection.
 
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