I have toshiba 46PX200ZE led tv which has a 64 led side backlight array.
The picture went black and I took out this side led array I found one of the leds
has gone bad as it would come on for a couple of seconds only. I photographed and discovered the bad led and tried to replace it with a 6.1 volt zener.
I was not able to make it work.
I was able to light the leds by applying about 3 volts on them. Now I cannot do so, even though they pass the diode continuity test on the multimeter.
Do leds show this even if they do not light up?
What can I do to repair...
spdy
Member
Last Activity: 11-07-2020, 12:33 PM
Joined: 05-28-2018
Location: new delhi, delhi
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Toshiba 46PX200ZE led tv screen is dark
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Bose mini soundlink
I have a bose mini 1 soundlink, the older version 6 buttons that has stopped working, shows only a red light. I replaced the battery of this with another one from a working unit, but this still shows red light.
Unfortunately no schematic or any other information is available on this.
I would like to fix it and use it without the battery, which is very expensive
and I do not need it.
So far I can see this has a battery regulator ic bq24172 and another ic 564( unable locate any data on this), three mosfets k7k, on the charger input board.
The ic 564 has 6 pins... -
Re: Zener T3D98 data required
Thanks, that is why it is showing open on the dmm diode check. I will have to look at the power supply section of this tv again. -
Re: Zener T3D98 data required
Thanks. I have desoldered and checked it is open on both sides. I want to know if they have higher threshold voltage and therefore it does not show on the dmm I am using.
I would also like to know what should be the voltage of a zener being used accross the bridge rectifier and trasnsformer of the smps?Leave a comment:
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Zener T3D98 data required
I am trying to repair a Panasonic plasma 42 inch TV TH-P42C10D. one of the suspicious components is a Zener T3D98 which is showing infinite resistance on both sides using a diode check with a multimeter.
I cannot find any data on this. I presume this is a high voltage 100, 150 or 200 volts zener in the power supply after the bridge rectifier and parallel to the transformer input.
How can I get data on this and can it be checked with a DMM?
Thanks. -
Re: Bose soundtouch 30 woofer works tweeters do not
Sorry I have delayed replying, I finally decided to substitute this with a small amplifier board using the same ic tpa3100d2, which costs only a few dollars, but ordered two from separate sellers, as one got lost.
Now this unit is working well. I removed the old ic completely.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
Thanks, the MSTR/SLV and Gain 1 and Gain 0 appear to show zero volts. I have been unable to trace the ROSC resistor (supposed to be 100K, but was reading 35K) so far.
I only saw it connected to a very small capacitor, which I have removed.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
ROSC shows a resistance of 35K (the data sheet shows this as 100K) and a voltage of 1.7.
VBYP shows 1.2 volts.
I also cannot understand why speaker voltage (on all four pins) is 7.6, which I earlier thought was OK, but now understand should be half of power supply voltage.
MUTE and FAULT show zero volts and shutdown is about 3.1 volts.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
The woofer ic is "TDF8599B" not the one mentioned in my earlier message.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
Thanks. The AVCC PVCCR and L show 23.6 volts.
The woofer, which is working, is powered by another ic, TDF8995B using same power supply has about 11 volts on the speaker terminals.
I will try to check the other points you have mentioned.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
Yes, the speakers are OK.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
The fault and mute show zero voltage, the shutdown is showing 3.1 volts and Vreg shows 4 volts.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
I have today replaced this ic , TPA31002d, but I am still not getting any sound in the speakers (tweeters) though now both sets of output pins show 7.6 volts with speakers connected.
Obviously the previous ic was defective.
As I had mentioned earlier previously the smps used to go to zero volts when speakers were connected, this is not happening now, with the new ic.
The woofer which is powered by another ic, continues to work.
I am able to trace the audio into the input of the ic TP...Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
I have just discovered that the smps shuts down if I signal trace the audio, when the woofer is working (with tweeter speaker disconnected).
I have another small amplifier which I use as a signal tracer, if I connect this to the audio in.
of the tweeter ic it gives good quality sound.
But if I connect this to the woofer ic audio in, the smps immediately shuts down.
This puts a small doubt in my mind about my thinking the tweeter ic is bad.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
You are right.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
Thanks, most of the other amplifiers I have seen hardly show any voltage at the speakers
and very often one of the outputs is grounded
The tweeters are OK and have been checked from another sound source again.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
I still cannot understand why the tweeter voltage is about 9.3 on one pin of each and zero on other in both speakers (tweeter disconnected) unlike the woofer which shows about 11.9 on both pins (woofer disconnected). The pins with zero show about 520 ohms resistance to ground.
Also the voltage to the resistors to the tweeter ic input pins show
1.8 volts for three inputs and 3.2volts on the fourth.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
Thanks the woofer shows 11.9 volts each on both pins, to the groundLeave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
I have not been able to get a circuit diagram for this, but found a service manual, which can be downloaded here
and would be grateful, if anybody can locate the schematic.Leave a comment:
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Re: Bose soundtouch 30 woofer works tweeters do not
Thanks, so far I have not been able to trace out the capacitors to pins RINN, RINP, LINN, LINP. I do see two sets of bank of four resistors of about 103 ohms each for both the TPA31002d ic and the woofer ic. These appear to go to the input output circuitboard.
The input to the resistors for the TPA31002d IC shows 1.8 volts for three inputs and 3.2volts on the fourth.
The woofer bank of resistors shows about 2.3 volts on each of the four.Leave a comment:
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