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BRONZE MemberAssuming the LED is getting power, I would check that the collector of 1TR17 transitions from 0 to 20v when a black stripe goes by. BTW, the service manual has a troubleshooting flowchart for this specific issue.
There is a clear right-angled plastic piece that has black lines on it that moves with the tonearm There is a lamp in a black plastic housing that illuminates a photodarlington transistor. I would check that that lamp is working. If it is, the the transistor may be bad. The detection of those black lines are necessary to find the edge of the record, switch to 45 and return after playing.
The 7000 has active cooling using a fan. Is that running? Are you measuring this at idle? I believe the fan kicks on at 50 degs.
Only the 33 button will cause the platter to spin for cleaning purposes. Once you have the arm moved over and paused, then pressing the 45 button should change the speed and illuminate. Can you move the arm over using the Play button and push the Cue buttin to cause it to lower and begin playing. If that doesn’t work, there may be an issue with the solenoid circuit or its mechanicals. The area should go up and down with the Cue button at any point except rest.
First focus on it not finding the record. The lamp+Photocell handles this at the end of the fixed arm. Do you see the B&O logo at the end lit up? If not that bulb needs replacing. If you are, then the lamp’s and photocell’s alignment may be off. The black insert pulls out of the arm enough to allow it to drop down in most cases or you can remove the arm screws under the cover.
How are you connecting it? Type of cable – DIN or RCAs? Phono Input on what component?
That could be multiple adjustments. Go through the adjustments detailed in the above service manual.
Not sure which adjustment you are seeking. Take a look at this service manual for all. https://beomanuals.com/manuals/Beogram/Beogram%202400/Bang-Olufsen-Beogram_2400-Service-Manual.pdf
Yes you can use an SP9 which has an elliptical diamond.
The fact that you got both channels working albeit at a low level into the Sonos points to the Beomaster phono inputs. You stated you have the RCA DIN adapter. I would try that as it allows you to switch channels to see if the bad channel follows. If it does not then it’s a Beomaster problem.
When muted all pins are connected. That’s where the 0,2-0,3 Ohms come in. When unmuted, the L- and R- are still connected (signal ground), so when measuring between L+ and R+ you are measuring the two coils in series. Their common center connection to ground doesn’t matter, seeing as you are not measuring with respect to ground.
Martin, I was not commenting on the first diagram. It’s the second that is wrong. It should read
* 1480 *
740. 740
*. .0.2 *Those do not look right. Measure the cartridge pins when it’s not installed. The pins are looking from the back: L+. R+ L- R- The 740 ohms should exist between L+ to L- and R+ to R-. There should be no resistance between R+ and L+.
Unmuted; When the cartridge is fitted to the arm, the two coils have their respective negative ends connected to signal ground. This means that if you measure from L+ to R+, you measure the two coils in series (2x 740 = 1480). All fine. Muted; All cartridge pins are connected to signal ground. All fine. Martin
Martin, I agree but the diagram is still wrong as a single pin cannot have 1480 and .2 ohms. It would be 1480 and 740 ohms.
Those do not look right. Measure the cartridge pins when it’s not installed. The pins are looking from the back:
L+. R+
L- R-
The 740 ohms should exist between L+ to L- and R+ to R-. There should be no resistance between R+ and L+.
The muting switch shorts the signal to so your ohm readings are correct. What you need to measure is when the cartridge is plugged into the arm and the switch unmuted you should see around 800 ohms on both channels.
I’ve not worked on one but I believe from the manual that there is a snap on LED cover that you remove to release it and the wire stays attached to the LED.
To narrow down where the fault lies try all sources to see if the channel is missing from all or just one or more. If all, then I would look at the preamp area prior to the mono switch and check for bad solder joints especially a the board connectors.
I addition to Guy’s excellent tips, if you have a multimeter you can measure the resistance between the top and bottom pins of each side of the cartridge. The readings should be a within 2% of each.
The section hcraig244 posted is correct.
Check the link in my first reply to you for the relay.
As long as the cartridge body (coils) is fine you can simply replace the stylus. The SP-9 was the elliptical version of your SP-7 and is available on the web such as https://www.lpgear.com/product/BOSSP09.html.
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