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Old 3rd May 2008, 09:47 AM   #1
WNR is offline WNR  Australia
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Question Cyrus 2 no output after short fall

My beloved cyrus 2 built 1986 recently fell about a foot front-first off a low shelf and, perhaps not surprisingly, wasn't happy about it ? Power on is OK but there is no output using the CD input. All I can hear is a very weak ouptut through the L channel only, barely audible and it doesn't increase when the volume control is increased. I have removed the cover and cannot see any obvious physical damage.

I am a Pom currently living in Sydney and a chemist by training. Though not great with electronics I can find my way around a schematic and have access to 'scopes etc. and electronics labs and friendly electrical engineers if necessary. I would appreciate any advice on troubleshooting this problem. I have the issue 07 cyrus 1 schematic from this forum. Alternatively any suggestions for repair shops preferrably in Oz or in the UK (will be back there briefly in Jan 09 if not before) would be great.

Many thanks in advance
Bill R, Sydney
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Old 3rd May 2008, 10:12 AM   #2
AndrewT is offline AndrewT  Scotland
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Hi,
the volume control probably hit the floor.
It may have cracked the pot track or the connection to the PCB.
Do any other inputs still work correctly?
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Old 3rd May 2008, 10:18 AM   #3
MadMutt is offline MadMutt  Australia
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If it landed front first on the selector knob, and the cd input is the only fault, I would say the selector switch is broken.
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Old 3rd May 2008, 02:25 PM   #4
Mooly is offline Mooly  United Kingdom
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PCB cracked around input sockets, was it connected at time.
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Old 11th May 2008, 11:14 AM   #5
WNR is offline WNR  Australia
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Hi Andrew, MadMutt & Mooly,
Thanks for your posts which prompted me to investigate further:

Quote:
Originally posted by AndrewT
Hi,
the volume control probably hit the floor.
It may have cracked the pot track or the connection to the PCB.
Do any other inputs still work correctly?
No, all inputs behave in the same way - hear L channel (only) at v low volume, with no response to volume control.
The volume contol has indeed taken a hit. The rearmost of the 2 small vertical mounting boards has broken completely in two allowing the control to be tilted forward at a crazy angle (see image apologies for quality).
Are their actually traces on that rear PCB or is it purely mechanical - it's hard to see?

I guess that at least that whole volume contol assembly will need to be checked out and repaired. Any practical tips for doing that - it doesn't look easy to get at? I haven't yet removed the main board from its metal case.

Quote:
Originally posted by MadMutt
If it landed front first on the selector knob, and the cd input is the only fault, I would say the selector switch is broken.
Selector switch seems OK.

Quote:
Originally posted by Mooly
PCB cracked around input sockets, was it connected at time.
All the inputs behave the same way. Yes it was connected at the time, but I guess I should investigate the vol control issues first?

Cheers, Bill
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Old 11th May 2008, 11:18 AM   #6
Mooly is offline Mooly  United Kingdom
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Looks pancaked to me. You need a new one, at least if you can't repair the PCB. The board within the pot may well be cracked as well.
Regards Karl
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Old 11th May 2008, 02:10 PM   #7
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I managed to get an alps 'blue' into the Cyrus 2. It was a bit tight, some pin bending was needed and I replaced the balance control with fixed resistors (optional).
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Old 23rd December 2012, 04:26 PM   #8
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Hi Martin!

Is there a chance to get the model number of the poti an a workaround with the restistors? Thanks.

Regards
wolkenlos
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Old 23rd December 2012, 08:43 PM   #9
jaycee is offline jaycee  United Kingdom
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The Cyrus 2 effectively has a passive pre. You can leave the balance pot disconnected without any resistors. A good quality logarithmic volume pot is all you really need. The original is a 10K pot.
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Old 24th December 2012, 02:14 PM   #10
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Well thank you.... Jaycee - I will try to get one of these alp blue 10K
This Model?
http://www.partsconnexion.com/product7384.html

My Problem with the Cyrus 2:
The left channel is more quieter than the right. Since the balance control does not work I thought that maybe this is the reason. Volume Power of the left channel 50%

regards
wolkenlos

Last edited by wolkenlos; 24th December 2012 at 02:26 PM.
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