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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc. |
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3rd Mar 2011, 1:54 pm | #21 |
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Re: Revox PR99 Mk2
The album can be seen by clicking on jorsagon's username to the left of his posts and then clicking on "View Public Profile".
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3rd Mar 2011, 11:22 pm | #22 |
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Re: Revox PR99 Mk2
I had a look at the diagrams but its hard to pinpoint the problem without having the machine in front of me.
In the PR99, the local keys go to the fader start logic board which in turn is connected to the tape drive board. The fault could lie in either of these, Firstly put your meter on the collector of Q11, it should read 0V but most likely will read be around 24V. Now remove plug J2 and repeat the test, if the collector of Q11 is now 0V the fault lies in the fader logic board, but if it reads 24V the problem lies with the transport board. See tape drive picture below |
4th Mar 2011, 2:23 am | #23 |
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Re: Revox PR99 Mk2
Is the remote plug/link in?
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4th Mar 2011, 11:44 am | #24 |
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Re: Revox PR99 Mk2
Tim, The B77 and PR99 doesn't require the remote plug. that was exclusive to the A77 and I believe the earlier 36 series.
One thing I should have explained, the stop line needs to be at 0V. Stop is activated by applying 24V to the stop line. This can be done in 4 ways, possibly more. 1. Local stop button 2. Remote control stop button 3. The edit lever is engaged 4. The end of tape sensor is triggered. To carry out the tests in my last post you must cover the photo cell either by having a tape threaded or by covering the sensor. |
5th Mar 2011, 1:12 pm | #25 |
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Re: Revox PR99 Mk2
thanks for the help. Tonight will try what you mention. thanks
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9th Mar 2011, 1:41 am | #26 |
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Re: Revox PR99 Mk2
sorry for the delay but I just started a bussiness trip for 2 weeks so please wait until I return. thanks for your help
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18th Mar 2011, 11:02 pm | #27 |
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Re: Revox PR99 Mk2
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19th Mar 2011, 1:13 pm | #28 |
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Re: Revox PR99 Mk2
Hi Michael
Just took a reading as you suggested at #10 on this thread .I get 28.2v and 4v without tape and28.2 and 0v with tape. BOB. |
19th Mar 2011, 11:02 pm | #29 |
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Re: Revox PR99 Mk2
That doesn't look right to me, I'll check with my B77 later and report back.
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9th Jul 2011, 9:44 pm | #30 |
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Re: Revox PR99 Mk2
Hi Michael
Thanks for getting back to me. Problem is now fixed. Bob. |
9th Jul 2011, 10:17 pm | #31 |
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Re: Revox PR99 Mk2
Perhaps you'd like to tell us what you found wrong and how you fixed it.
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11th Jul 2011, 1:57 pm | #32 |
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Re: Revox PR99 Mk2
Hi Michael
I had to send it off to get fixed.It was a tantalum capacitor on the small board attached to the tape dump button.Cost of the capacitor was 10p but was charged a lot more because he charged me for other things which were changed in an effort to find the faulty component such as the end of tape sensor (£44).it also took him two months to fix it.Not a pleasant experience but i'm learning a lot from the A77 which are a lot simpler than the pr99.I wish now i had persevered with it myself because this board was the next thing on my to change list.Hope this is of some help to others. Cheers BOB. |
11th Jul 2011, 11:17 pm | #33 |
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Re: Revox PR99 Mk2
It would seem that the capacitor is C2 was the culprit, being a tantalum it might have failed short circuit putting 24V on the stop line. I thought we'd eliminated the EOT sensor in previous posts.
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