Help, can't find resistor R3102 on my CD3300 servo board?

6 replies
98
Offline
987nick
Bronze
Posted December 2, 2024 at 14:20 GMT
#1644208
I thought I'd fixed my CD3300, type 5142, as I managed to get it to play most of my CDs.  I've replaced all electrolytic capacitors on the power supply, decoder board and servo board.  But, after leaving it for a few days it now plays none of them.   In most cases the TOC are read, but it won't play.

I now want to check the laser power.  The service manual says to put a meter across R3102 to check the mv.  But, my servo board, number 5886 on the sticker, doesn't seem to have that resistor.

I've attached pictures of both sides of the board and would really be grateful if  someone could point me to the resistor.
Attachments (2)
Guy
Online
Guy
GoldModerator
Posted December 2, 2024 at 15:12 GMT
#1667443
Does para 6 and 7 of this help - looks similar!

Location: Warwickshire, UK

My B&O Icons:

BeoCenter-9500.png BeoCenter-9500.png
Beoremote-Beo4.png Beoremote-Beo4.png
Beovision-10.png Beovision-10.png
Beotime.png Beotime.png
Beosound.png Beosound.png
Beosound-Explore.png Beosound-Explore.png
Beosound-Essence.png Beosound-Essence.png
Beoplay-P2.png Beoplay-P2.png
Beoplay-M3.png Beoplay-M3.png
Beoplay-H4.png Beoplay-H4.png
Beoplay-H3.png Beoplay-H3.png
Beoplay-Form-2i.png Beoplay-Form-2i.png
Beoplay-Earset.png Beoplay-Earset.png
Beoplay-A2.png Beoplay-A2.png
98
Offline
987nick
Bronze
Posted December 2, 2024 at 17:15 GMT
#1667445
I've seen that and it does look familiar.  And, that's how I knew I don't seem to have a resistor in the same place.  My board has a gap.
98
Offline
987nick
Bronze
Posted December 6, 2024 at 13:01 GMT
#1667494
Just to bump this, any other suggestions?
GL
Offline
Glitch
Bronze
Posted December 6, 2024 at 13:38 GMT
Edited December 6, 2024 at 13:38 GMT
#1667497
If you can't find the part marking directly on the board, an indirect method might work. First find the part on the schematic and see which parts that it is connected to. Then search for the "connected parts". It is sometimes helpful to track the connectivity to a obvious part (like one of the TDA chips) and start following traces from a specific pin number. Don't forget to check both sides of the board. I recall working on a similar board and the resistor in question was a surface mount device mounted on the back side of the board.

Following the traces can also be helpful for finding convenient places to attach the test leads.

Glitch
98
Offline
987nick
Bronze
Posted December 6, 2024 at 15:14 GMT
#1667498
@glitch Thanks.

I've found it.  Turns out it is in line with the IC by the ribbon connector and not to the side.  Turns out the CD3300 service manual has another servo board detailed right at the end of the book.  I was looking at the 1st one in the book.  I should have learnt by now to read right to the end before I waste people's time.

Now off to test the laser power output.
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