Also I tried to repair the same PCB but with the 2 bridges (see 1st page).
Here is another problem. All ecaps changed by me. Everything is also checked.
On this PCB the buld is not working and I have:
C2 - R9 - 166mV
C2 - R10 - 690mV
t4 B-E 0.44V
T4 B-C 0.31V
Bl motor pot - C2 - 0.19V
Bl motor pot - C3 - 0.19V
What is dead here?
Here is another problem. All ecaps changed by me. Everything is also checked.
On this PCB the buld is not working and I have:
C2 - R9 - 166mV
C2 - R10 - 690mV
t4 B-E 0.44V
T4 B-C 0.31V
Bl motor pot - C2 - 0.19V
Bl motor pot - C3 - 0.19V
What is dead here?
Cracked and glued 
Yep, that's hidden history all right
If you are sure the board is OK (check check and check again and also prod and poke the board to make sure there is no hidden crack or problem joint) then I would mark the position of the pots and try adjusting them slowly. You can always set them back to where they were if it makes no difference. Try adjusting R17 a little. Its possible the settings are motor dependent... different motor... different settings.
If that's no good and the problem is consistent, that is to say it works for a minute or so when cold and then goes faulty, then careful use of freezer spray might be useful.
Try adjusting first though. Alter the presets one at a time and slowly and see what they do.
Yep, that's hidden history all right If you are sure the board is OK (check check and check again and also prod and poke the board to make sure there is no hidden crack or problem joint) then I would mark the position of the pots and try adjusting them slowly. You can always set them back to where they were if it makes no difference. Try adjusting R17 a little. Its possible the settings are motor dependent... different motor... different settings.
If that's no good and the problem is consistent, that is to say it works for a minute or so when cold and then goes faulty, then careful use of freezer spray might be useful.
Try adjusting first though. Alter the presets one at a time and slowly and see what they do.
R10 should have the full supply voltage on it if its the same basic circuit as the one we are working to here.
So that fault sounds like broken print. Confirm the supply voltage is OK across C2 and C3 and then just trace the print to R10.
You need to concentrate on one board. Its too confusing to be talking about two faulty units at the same time.
The one we are talking about here in post #99
http://www.diyaudio.com/forums/anal...-help-me-please-repair-pcb-5.html#post4371999
Have you tried tweaking the pots ?
The one we are talking about here in post #99
http://www.diyaudio.com/forums/anal...-help-me-please-repair-pcb-5.html#post4371999
Have you tried tweaking the pots ?
You say in post #99 that it now works for a little while before doing strange things. That gives you something to work to... is it temperature related, some part heating and breaking down. That is where freezer spray would be useful. Make sure there is no volt drop across sections of print as measured end to end with it all powered up and working. That might show a hidden break.
I'm sorry I've no magic answer and its difficult without having the unit in front of me to get a feel for what its doing.
I'm sorry I've no magic answer
and its difficult without having the unit in front of me to get a feel for what its doing.
Look at the picture in post #1
If you have no voltage on R10 then you should measure from its source at C3 and then go along the print all the way to R10. If there is no voltage on C3 then check the print back to the bridge and so on. If there is a break in the print then there will be a volt drop across it (like a broken wire).
If you have no voltage on R10 then you should measure from its source at C3 and then go along the print all the way to R10. If there is no voltage on C3 then check the print back to the bridge and so on. If there is a break in the print then there will be a volt drop across it (like a broken wire).
It looks like you are getting some superb expert advice from Mooly here.
I don't want to knock you off track but here's my top tips:
I've got two TD125's and on both the PCB had hairline cracks which needed repairing. On one the crack was almost invisible and I only found it by checking for continuity with a multimeter. I had to replace the transistors on one also, they get rather hot and I don't think they're terribly reliable.
Also check and check again the contacts on the speed selector switch. I bit of deoxit would be good on these and while you're at it flush the fine speed adjuster through with contact cleaner.
Persevere, the TD125 is a superb turntable.
I don't want to knock you off track but here's my top tips:
I've got two TD125's and on both the PCB had hairline cracks which needed repairing. On one the crack was almost invisible and I only found it by checking for continuity with a multimeter. I had to replace the transistors on one also, they get rather hot and I don't think they're terribly reliable.
Also check and check again the contacts on the speed selector switch. I bit of deoxit would be good on these and while you're at it flush the fine speed adjuster through with contact cleaner.
Persevere, the TD125 is a superb turntable.
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