Low level hum from sub woofer on side.
Check C3 and C5 470uf 25 volt caps. EEU-FR1E471L They are located on the large heat sink on the back of the cabinet.
After replacing them you may still have a small hum, if you want to get it all replaced the 6800uf 80 volt caps.
Thursday, December 18, 2014
Wednesday, April 11, 2012
M-Audio BX5 repair
Unit had no sound. Pushing on the woofer cone slightly, resulted in a increase buzzing sound.
Take the back off of the unit and remove the wires from the LED Woofer and Tweeter.
I have found that the picture can save you lots of time when you have to leave a unit for several weeks. Nice to look and see qickly how the unit goes back together
Power the unit back on and test for DC on the woofer and tweeter connectors, found less than 1 volt.
Did not think that both of the LM3886TF IC were bad. Looking at the input pin 10, I find no music. output pin 3 had a strange wave form that was not affected by level.
Checking the bridge, found 24v and -16v, the 6800uf 25v caps ends were pushing out, they would have to be replaced anyway. After replaceing them the voltage return to -24 and +24. They are running the power supply at max with 25 volt caps. Did not have any 35 volts that would fit.
When removing the caps, cut the glue from arround the caps first. This PCB is double sided with eyelets that connect between each side. If you rip out the eyelets when removing the caps you will have to solder a jumper wire to complete the path.
We use the NHG series cap for replacment. Purchase Caps
Unit now is working again.
Take the back off of the unit and remove the wires from the LED Woofer and Tweeter.
Power the unit back on and test for DC on the woofer and tweeter connectors, found less than 1 volt.
Did not think that both of the LM3886TF IC were bad. Looking at the input pin 10, I find no music. output pin 3 had a strange wave form that was not affected by level.
Checking the bridge, found 24v and -16v, the 6800uf 25v caps ends were pushing out, they would have to be replaced anyway. After replaceing them the voltage return to -24 and +24. They are running the power supply at max with 25 volt caps. Did not have any 35 volts that would fit.
When removing the caps, cut the glue from arround the caps first. This PCB is double sided with eyelets that connect between each side. If you rip out the eyelets when removing the caps you will have to solder a jumper wire to complete the path.
Unit now is working again.
Wednesday, October 6, 2010
LJ92-01511A Power Supply PCB
LJ92-01511A
Power Supply PCB
Use in
Philips 50PFP5332D/37
Common problem is the caps. Change any that are puffed on the end.
DC8104
DC8105
DC8107
DC8413
DC8414
They are 680uf 50v.
DC8013 1000uf 16v
DC8419 3300uf 10v
If you find other parts bad on this item please post.
Sunday, October 3, 2010
Bose CD-20 Repair notes
This is for service techs that have basic electronic training!
CD skipping or noisy. The replacement of 4 caps Caps C851 C852 C863 C864 on control PCB located under the transport should be done before replacing the laser. NEVER TURN THE ADJUSTMENT ON THE PCB. You must have the manual and test equipment to get it back working.
CDs will not eject or change and makes a buzzing sound. Check gear on load motor, it splits and shaft spins on it. Use expoy and attach it to shaft. If split is too wide then you must replaced the gear 189099 (Sorry we only have a few left, so no sales of gear only.) Update 12-26-2012. If you or the owner of the unit has pushed the eject so many times it has overheated the motor it maybe bad. Unplug the ribbon cable from the main PCB and apply 9 volts from a battery . It should spin if ok. If this motor is bad nothing will work.
Please do NOT glue the gears to each other!!
Check Q851 2SC2412K could be loose or bad on cd PCB.
Display low and/or CD not working
Power supply save time and change all the caps on the PCB. Must change C24 C27
Q10 was 2SB1142 change to 2SB1136 and turn it around. Have a mod for older pcb.
If after changing the caps the display is still dim, then you need to change the display tube.
Lighting hit - Change Q102 Q104 2SA608 Sometimes the resistors are also open. Most likely the bass amp also has problems, that is a little hard thing to repair. Requires the replacement of over 20 components for power surge.
Audio popping noise or motor boating.
Change TDA7313 U102 U100
We repair this unit if you need repair service. Flat Rate is$100.00. New Price $125.00
If you would like to sell one, we pay $25.00 for them to use for parts. We will pay shipping cost.
For the people who have a lighting hit unit, you will need to repair the sub woofer also. I will post the repair for that later. You will need to replace over 20 ICs in that unit. Takes over 3 hours.
We charge $250.00 to repair complete system if it is a digital system (series II).
I have full service manual in paper form.
Contact us
Audio Lab of Ga
www.audiolabga.com
1 770 455 0571
sales@audiolabga.com
-->
ViewSonic RLC-072 Replacement Lamp (Google Affiliate Ad)
CDs will not eject or change and makes a buzzing sound. Check gear on load motor, it splits and shaft spins on it. Use expoy and attach it to shaft. If split is too wide then you must replaced the gear 189099 (Sorry we only have a few left, so no sales of gear only.) Update 12-26-2012. If you or the owner of the unit has pushed the eject so many times it has overheated the motor it maybe bad. Unplug the ribbon cable from the main PCB and apply 9 volts from a battery . It should spin if ok. If this motor is bad nothing will work.
Please do NOT glue the gears to each other!!
Check Q851 2SC2412K could be loose or bad on cd PCB.
Display low and/or CD not working
Power supply save time and change all the caps on the PCB. Must change C24 C27
Q10 was 2SB1142 change to 2SB1136 and turn it around. Have a mod for older pcb.
If after changing the caps the display is still dim, then you need to change the display tube.
Lighting hit - Change Q102 Q104 2SA608 Sometimes the resistors are also open. Most likely the bass amp also has problems, that is a little hard thing to repair. Requires the replacement of over 20 components for power surge.
Audio popping noise or motor boating.
Change TDA7313 U102 U100
We repair this unit if you need repair service. Flat Rate is
If you would like to sell one, we pay $25.00 for them to use for parts. We will pay shipping cost.
For the people who have a lighting hit unit, you will need to repair the sub woofer also. I will post the repair for that later. You will need to replace over 20 ICs in that unit. Takes over 3 hours.
We charge $250.00 to repair complete system if it is a digital system (series II).
I have full service manual in paper form.
Contact us
Audio Lab of Ga
www.audiolabga.com
1 770 455 0571
sales@audiolabga.com
-->
ViewSonic RLC-072 Replacement Lamp (Google Affiliate Ad)
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