JBL ES150P Subwoofer - repair

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hello,
Subwoofer have top LED diode. When power is on, LED status is red colour means no signal detected. My subwoofer, after turning power on shows red LED and blinks in green colour for very short time. Between blinks is approx. 0,8 sec. Parallel to blinks there is a silent click sound from PCB. Sound is coming from area marked in red rectangle:
01.jpg
Closer look to PCB:
02.jpg 03.jpg

After unplugged PCB with inputs/vol knob/etc. - clicking sound is 2 times faster.

Checking DC voltage on speaker pin, my multimeter starts from zero and growing up to 200 mV after 15 sec. Then multimeter restarts.

Voltage from transformer seems to be correct. Voltage on DCPWR are:
Vbb = 122 [V]
Vcc = 45[V]
PN15V = 14,2 [V]
09.png


I've checked Q10, Q10B & Q11 transistors - ok.

04.png

Service manual: https://data2.manualslib.com/pdf3/7...?7ec59da05affd312a5373c2fd869e334&take=binary


Could you help me fix subwoofer please? What I should check in next step?
 
Thank you for your reply. I removed that glue from PCB. I found that one leg of yellow capacitor was unsolder (shown below):
10.jpg

When turning power switch on, hear loud click of transmitter. When off - transmitter click once again. It looks like this solve problem, but tomorrow I will assembly electronics with subwoofer box.

Should I put new glue on area where original glue was? Can I use silicone instead?

I replaced faulty resistors R214 & R244 to new one. I use carbon resistors instead fuseresistor like manual says. Is this big issue?
11.png
 
I can't see it clearly on the photo, but the TO220 cased component at the yellow arrow appears to have a short circuit between its center leg and the circuit board.
That brown stuff on the yellow capacitors, is it glue? If not, they look like they are damaged.

Voltage from transformer seems to be correct. Voltage on DCPWR are:
Vbb = 122 [V]
Vcc = 45[V]
PN15V = 14,2 [V]
View attachment 748387
Do both positive and negative voltages have these values?
 
Last edited:
Subwoofer works well! :D

I can't see it clearly on the photo, but the TO220 cased component at the yellow arrow appears to have a short circuit between its center leg and the circuit board.
That brown stuff on the yellow capacitors, is it glue?
I enclose better photo - no short circuit. And yes - that's brown glue.
12.jpg

Do both positive and negative voltages have these values?
Yes, both have the same value.

I didn't used any glue or silicone on PCB. Also I left carbon resistors instead fuseresistor.

Thank you all so much for help :)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.