JBL EON 515XT No Treble

[nosaj]

Replaced TDA7293. Checked continuity to all 15 pins. All beep, but no tweeter(treble) function.

What exactly does this mean? You have continuity between all 15 pins or ??
nosaj

[ca7922303]

What exactly does this mean? You have continuity between all 15 pins or ??
nosaj

To make sure all the pins were soldered in right, I checked each pins connection per the schematic and got a continuity beep at each one, for example, pin #3 to R407.

[nosaj]

Ok powered on what are the voltages on the IC?
nosaj

[ca7922303]

Ok powered on what are the voltages on the IC?
nosaj

1(0mv)
2(-2.4mv)
3(0.5mv)
4(0mv)
5(-0.5mv)
6(16.2v)
7(25.6v)
8(-25.7v)
9(7.9v)
10(7.7v)
11(-1mv)
12(15v goes down to mv)
13(25.5v)
14(-0.3mv)
15(-25.6v)

[g1]

Those voltages all look good. Try injecting your 3Khz signal at the junction of R405/C403/C404.

[ca7922303]

Those voltages all look good. Try injecting your 3Khz signal at the junction of R405/C403/C404.

Can you recommend a method to inject 3khz signal at intersection. Also, R405 is (3.6k).

[ca7922303]

Photo of R405, C403/404. Now that I've magnified, is that the test point right above D310?

[g1]

1) That NTE part is the sub for TDA7294, not 7293. If you are going to use NTE substitute, you need NTE7186. Again you will have to bend the leads for horizontal mount. If you can find a real TDA7293HS you will not have to bend the leads.

2) Some of the via's are torn out where the pins go through the board. Via's are like little pipes that connect the traces on bottom of the board to traces on top of the board. It looks like you only soldered the IC on the bottom side of board. You need to solder the pins to the top side of board where ever there are traces and vias are missing..

3) You only need a thin layer of heatsink grease. Too much can actually reduce thermal contact instead of helping it.

[ca7922303]

1) That NTE part is the sub for TDA7294, not 7293. If you are going to use NTE substitute, you need NTE7186. Again you will have to bend the leads for horizontal mount. If you can find a real TDA7293HS you will not have to bend the leads.

2) Some of the via's are torn out where the pins go through the board. Via's are like little pipes that connect the traces on bottom of the board to traces on top of the board. It looks like you only soldered the IC on the bottom side of board. You need to solder the pins to the top side of board where ever there are traces and vias are missing..

3) You only need a thin layer of heatsink grease. Too much can actually reduce thermal contact instead of helping it.

There's a lot of misinformation on the internet about the tda7293 being interchangeable with the 7294. I see where NTE cross reference shows the NTE 7165 replacing tda7294, not the 7293. I guess I saw where some pages on Google suggested they were interchangeable, but I see the difference now in the pinouts. Appreciate the info. Any chance that with the top of board pins being soldered correctly, that this 7165 might work on it? You did comment that the voltages looked correct. Thanks.

[ca7922303]

1) That NTE part is the sub for TDA7294, not 7293. If you are going to use NTE substitute, you need NTE7186. Again you will have to bend the leads for horizontal mount. If you can find a real TDA7293HS you will not have to bend the leads.

2) Some of the via's are torn out where the pins go through the board. Via's are like little pipes that connect the traces on bottom of the board to traces on top of the board. It looks like you only soldered the IC on the bottom side of board. You need to solder the pins to the top side of board where ever there are traces and vias are missing..

3) You only need a thin layer of heatsink grease. Too much can actually reduce thermal contact instead of helping it.

Screenshot

[g1]

The 7294 (or NTE sub) will not work because the bootstrap cap at pin6 won't be connected to anything. Pin12 is in use and the 7294 doesn't have that.
If they were compatible parts, NTE would have 1 sub that could replace either one of them.
You would have to lift the end of the cap that connects to pin12 and connect it to pin14 instead. Then I can only say it might work.

[ca7922303]

The 7294 (or NTE sub) will not work because the bootstrap cap at pin6 won't be connected to anything. Pin12 is in use and the 7294 doesn't have that.
If they were compatible parts, NTE would have 1 sub that could replace either one of them.
You would have to lift the end of the cap that connects to pin12 and connect it to pin14 instead. Then I can only say it might work.

Thanks, I'll order the nte7186 and get back on it when it delivers.