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Old 08-05-2020, 08:19 PM   #21
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Ok I just tried resistance measurements in the new resistor leg and a black speaker lead

The resistor is testing just like a capacitor. I have my meter on ohms, I put red lead on resistor leg and black lead on speaker terminal, and then resistance starts at like .5, and goes up and up quickly to about 1.9 I think and then flashes OL and then jumps to 7.5 and climbs very slowly from there. When I take my probes away and put them back the resistance is slowly draining. On the way up it is kilo ohms and in the way down it is mega ohms. If I wait a min or so I can repeat the process

I took a bunch of pictures of that area of the board I will upload the best later tonight
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Old 08-05-2020, 08:55 PM   #22
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by budm View Post
1) Well, I told you not to power up the unit, you are just going to cause more damages. You are not going to listen, are you?
I tried those things before I saw your post.Trust me I am definitely listening and learning a lot!


Quote:
2) What Ohm scale of the Ohm meter did you set it to?
I just have a resistance setting on my meter, there are no finer controls than that.

Quote:
3) Measure the resistance between the speaker Black terminal (where the terminal is soldered to) and the AG pad of the connector, it should show < 1 Ohm.

I don't know what an AG pad is. I checked from the black speaker terminal to both the wires of the resister and the underside where the resistor is soldered in and it behaved that same way: Rapid increase to about 1.9 KOhm, then flash OL, then jump to 7KOhm and climb slowly, and if I take away my lead and place it back, it reads a number of Mega Ohms (the longer I test the first time the higher the reading) and it slowly and steadily declines. Thats what happened when I was testing capacitors.

Here is an HDR image from my phone I took by setting the phone on a pile of books so no shaking.

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Old 08-05-2020, 09:51 PM   #23
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by SluggerB View Post
Ok I just tried resistance measurements in the new resistor leg and a black speaker lead

The resistor is testing just like a capacitor. I have my meter on ohms, I put red lead on resistor leg and black lead on speaker terminal, and then resistance starts at like .5, and goes up and up quickly to about 1.9 I think and then flashes OL and then jumps to 7.5 and climbs very slowly from there. When I take my probes away and put them back the resistance is slowly draining. On the way up it is kilo ohms and in the way down it is mega ohms. If I wait a min or so I can repeat the process

I took a bunch of pictures of that area of the board I will upload the best later tonight
There are two resistors, one is burnt out and another one is not, you need to test each legs of those two resistor with ref to GND, so you should have 4 readings total
AG pad, if you look at the pin label of the connector, you see one pin is labeled with AG.
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Old 08-05-2020, 10:06 PM   #24
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Can you list the pin names of the connector as printed on the board? Some of the pins I cannot read.
Please also show the pictures of where that connector is connected too and any other boards that shows how all the boards are connected together.
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File Type: jpg Connector.jpg (308.7 KB, 2 views)
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Old 08-06-2020, 01:15 AM   #25
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

OK, after and hour or so I trace out the Minus and Plus regulated power supply sections, see picture attached, they are just simple linear regulator circuit using Zeners and Transistors (http://www.bristolwatch.com/ele/zener_power_supply.htm)

1) Check the resistance between GND (RED BOX AS MARKED) and V+.

2) Check the resistance between GND (RED BOX AS MARKED) and V-.

3) I see damaged solder pad of the resistor that was soldered too many time, make sure it still make connection and not shorted to the next pads, see picture attached.
Attached Images
File Type: jpg Damaged solder pad of resistor.jpg (1.79 MB, 9 views)
File Type: jpg V-PLUS V-MINUS REG.jpg (3.02 MB, 23 views)

Last edited by budm; 08-06-2020 at 01:26 AM..
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Old 08-06-2020, 04:45 AM   #26
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by budm View Post
OK, after and hour or so I trace out the Minus and Plus regulated power supply sections, see picture attached, they are just simple linear regulator circuit using Zeners and Transistors (http://www.bristolwatch.com/ele/zener_power_supply.htm)

1) Check the resistance between GND (RED BOX AS MARKED) and V+.

2) Check the resistance between GND (RED BOX AS MARKED) and V-.

3) I see damaged solder pad of the resistor that was soldered too many time, make sure it still make connection and not shorted to the next pads, see picture attached.
Yeah a little bit of the green stuff came off by the hole but the copper wire was still there and I tested for resistance from pad to pad and still got a reading so I think it's still good. Solder really doesn't want to stick to the spot it flaked off, I can keep trying to get it on there, I didn't want to put to much heat into the board. Close up I do not see any pads bridging, I will test to make sure

I will take all required measurements later today and I will label the image to match the connector labels. I am used to looking at boards where everything is labeled already so this one is a lot harder for me to follow. Thanks for the trace work it is much appreciated!

Also on a lark I checked that chip up top (the one with 8 legs) for shorts and it has none (I fault found a broken PS4 that way so figured I'd test it out)

Can you tell me your thoughts in asking for these readings so I can learn your methodology/thought process? Power seems to be flowing from power supply area, to that resistor, and the to the plug, which then takes power up and to the front control board, so I would have thought whatever would have been frying the resistor would be between the power supply area and the resistor, but you seem focused on the other side (and obviously know way more than me). What led you to focus on that side? I care way more about learning and getting better at this than fixing anything (although it would be really cool to get it working)
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Old 08-06-2020, 06:43 PM   #27
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Edit: Go Go reading comprehension, these aren't the readings you asked for. Let me go grab those ....

---------------------------------------------------------

Ok, readings as requests. Multimeter set to Ohms.

You boxed 2 contacts as ground, so I took 8 total readings, a reading from each side of each resistor to each ground.

Ground A (the one under the "G" in the box)
- Burning resistor, leg closest to ground: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
- Burning resistor, leg farther from ground: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.

- Good Resistor, leg closest to ground: 3.89 Ohms
- Good Resistor, leg farthest from ground: 3.89 Ohm


Ground B (the one under the "D" in the box)
- Burning resistor, leg closest to ground: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
- Burning resistor, leg farther from ground: OL. I tried several tests and made sure I had a good contact with leads, always OL.

- Good Resistor, leg closest to ground: 3.89 Ohms
- Good Resistor, leg farthest from ground: 3.89 Ohm


The lettering on that cable is as follows, top to bottom from the underside (like your traced pic)

CH A (what you have marked as "1")
CH B
CH C
CH D
CH E
CH F
V -
V +
AG
OUT
DVD
CD
DG
5V


That cable connects to another smaller board that all the front instrumentation and display is connected to. Those are the only 2 boards in the unit.

I also tried to clean up that solder connection where the green had peeled off and got it a little better. Since the pad is gone the solder is balling up a lot but I got it moderately better, the resistor still tests fine, so I'm not going to touch it anymore.


Wild guess, do these readings mean the zener diode on the channel with the burning resistor is bad and is allowing current to flow in a direction it shouldn't be allowed to? Possible allowing the capacitor on that line to dump it's charge back into the resistor?

Last edited by SluggerB; 08-06-2020 at 07:21 PM..
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Old 08-06-2020, 06:54 PM   #28
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by SluggerB View Post
Edit: Go Go reading comprehension, these aren't thje readings you asked for. Let me go grab those ....

---------------------------------------------------------

Ok, readings as requests. Multimeter set to Ohms.

You boxed 2 contacts as ground, so I took 8 total readings, a reading from each side of each resistor to each ground.

Ground A (the one under the "G" in the box)
- Burning resistor, leg closest to ground: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
- Burning resistor, leg farther from ground: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.

- Good Resistor, leg closest to ground: 3.89 Ohms
- Good Resistor, leg farthest from ground: 3.89 Ohm



Ground B (the one under the "D" in the box)
- Burning resistor, leg closest to ground: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
- Burning resistor, leg farther from ground: OL. I tried several tests and made sure I had a good contact with leads, always OL.

- Good Resistor, leg closest to ground: 3.89 Ohms
- Good Resistor, leg farthest from ground: 3.89 Ohm



The lettering on that cable is as follows, top to bottom from the underside (like your traced pic)

CH A (what you have marked as "1")
CH B
CH C
CH D
CH E
CH F
V -
V +
AG
OUT
DVD
CD
DG
5V


That cable connects to another smaller board that all the front instrumentation and display is connected to. Those are the only 2 boards in the unit.

I also tried to clean up that solder connection where the green had peeled off and got it a little better. Since the pad is gone the solder is balling up a lot but I got it moderately better, the resistor still tests fine, so I'm not going to touch it anymore.


Wild guess, do these readings mean the zener diode on the channel with the burning resistor is bad and is allowing current to flow in a direction it shouldn't be allowed to? Possible allowing the capacitor on that line to dump it's charge back into the resistor?
Are you 100% sure that the GOOD RESISTOR shows 3.89 Ohms?
How bout the reading of V- and V+ pins with ref. to GND.
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Old 08-06-2020, 07:17 PM   #29
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by budm View Post
Are you 100% sure that the GOOD RESISTOR shows 3.89 Ohms?
How bout the reading of V- and V+ pins with ref. to GND.

Yep. I checked every reading a couple times. Good resistor definitely tests 3.89

Here are the readings for V- and V+

Ground A (the one under the "G" in the box)
- V-: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
- V+: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.

Ground B (the one under the "D" in the box)
- V-: It starts at 1.2, then ramps quickly up to 9.42 - 9.45 ish and stays there
- V+: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
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Old 08-06-2020, 07:44 PM   #30
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by SluggerB View Post
Yep. I checked every reading a couple times. Good resistor definitely tests 3.89

Here are the readings for V- and V+

Ground A (the one under the "G" in the box)
- V-: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
- V+: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.

Ground B (the one under the "D" in the box)
- V-: It starts at 1.2, then ramps quickly up to 9.42 - 9.45 ish and stays there
- V+: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
Something does not make sense here, the BOX where I mark as ground, the pad where the G is and where the D is, they are connected together! so you cannot have difference readings, see the picture, as you can see A is connected to B.
It is just one test point for GND that we are using to locate the problem.
Your measurement does not make any sense.

You are probing on the bottom side of the board using my picture, correct?
Show me the pictures where you use as the ground point, and where you out the probe on the good resistor and bad resistor.
BTW, are BOTH resistors (180 Ohns) are in place? Did you measure the resistance of the good resistance to see if it actually shows as 180 Ohms?
Attached Images
File Type: jpg GND point for testing.jpg (2.75 MB, 9 views)
File Type: jpg V-PLUS V-MINUS REG.jpg (3.02 MB, 3 views)

Last edited by budm; 08-06-2020 at 07:57 PM..
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Old 08-06-2020, 08:26 PM   #31
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by budm View Post
Something does not make sense here, the BOX where I mark as ground, the pad where the G is and where the D is, they are connected together! so you cannot have difference readings, see the picture, as you can see A is connected to B.
It is just one test point for GND that we are using to locate the problem.
Your measurement does not make any sense.

You are probing on the bottom side of the board using my picture, correct?
Show me the pictures where you use as the ground point, and where you out the probe on the good resistor and bad resistor.
BTW, are BOTH resistors (180 Ohns) are in place? Did you measure the resistance of the good resistance to see if it actually shows as 180 Ohms?
Yes, I am following your picture of the bottom of the board. There are two different solder points where your box is. They are not bridged or touching.

I took your trace and superimposed it onto the picture of the top of the board, which I flipped horizontally in photoshop to align the orientation. The GND box appears to be two separate legs of two capacitors. Is that right?




And yes both resistors are in place and both test at 180 Ohms. One is the original one, the other one is the replacement I put in.
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Old 08-06-2020, 08:46 PM   #32
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Did you look at the last picture showing point A (you call it G) and point B (you call it D) tied are tied together? So how can you report difference reading between Ground A (G) and Ground B (D)?
I can see copper trace connecting the two pads together and top side also shows green line connecting them together on the top side of the board, all you need to do to verify if that is true or not by using Ohm meter to check it out..
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File Type: jpg GND point for testing SHOWN TOP SIDE.jpg (326.5 KB, 2 views)

Last edited by budm; 08-06-2020 at 08:56 PM..
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Old 08-06-2020, 08:58 PM   #33
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by budm View Post
Did you look at the last picture showing point A (you call it G) and point B (you call it D) tied are tied together? So how can you report difference reading between Ground A (G) and Ground B (D)?
I can see copper trace connecting the two pads together and top side also shows green line connecting them together.
I saw your picture but A and B don't look to be connected, the red lines you drew are not touching. They look like two spots to me. And I did test to each of them and got some different results. Qnd flipping the board over they seem to match up to two legs of two capacitors.

Should I try testing from V- and V+ to that black speaker terminal I used as ground before?

Your picture shows the positive and negative power rails, and indicates the problem is in the positive power rail since that is connected to the burning resistor. Looking at that on the board, from the resistor, we have:

2 capacitors
1 zener diode
2 resistors
3 transistors
1 capacitor

Do we think the issue is with one of those 9 components? If so, not that I would want to do this as I wouldn't be learning as much, but could I just replace those 9 components and fix the issue?

Last edited by SluggerB; 08-06-2020 at 08:59 PM..
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Old 08-06-2020, 09:03 PM   #34
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

And here is another problem of you readings:

You boxed 2 contacts as ground, so I took 8 total readings, a reading from each side of each resistor to each ground.

Ground A (the one under the "G" in the box)
- Burning resistor, leg closest to ground: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
- Burning resistor, leg farther from ground: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.

- Good Resistor, leg closest to ground: 3.89 Ohms
- Good Resistor, leg farthest from ground: 3.89 Ohm



Ground B (the one under the "D" in the box)
- Burning resistor, leg closest to ground: Tested like a capacitor, ramp to 1.9, the flash OL, then charge slowly, then on retest discharge slowly.
- Burning resistor, leg farther from ground: OL. I tried several tests and made sure I had a good contact with leads, always OL.

- Good Resistor, leg closest to ground: 3.89 Ohms
- Good Resistor, leg farthest from ground: 3.89 Ohm


It cannot be the same 3.89 Ohms since it is 180 Ohms resistor, so one end should show 180 Ohms higher resistance. You do understand that, right?

The readings based on you reading of 3.89 Ohms readings on both ends, means the resistor is dead short but we know it is not. 3.89 Ohms reading is also not normal either for the Minus power supply section if the readings are true.

We are not getting any where until we get valid data and not understanding basic electronics.
Attached Images
File Type: jpg Good resistor resistance readings against GND per OP.jpg (759.8 KB, 4 views)

Last edited by budm; 08-06-2020 at 10:15 PM..
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Old 08-06-2020, 09:21 PM   #35
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by SluggerB View Post
I saw your picture but A and B don't look to be connected, the red lines you drew are not touching. They look like two spots to me. And I did test to each of them and got some different results. Qnd flipping the board over they seem to match up to two legs of two capacitors.

Should I try testing from V- and V+ to that black speaker terminal I used as ground before?

Your picture shows the positive and negative power rails, and indicates the problem is in the positive power rail since that is connected to the burning resistor. Looking at that on the board, from the resistor, we have:

2 capacitors
1 zener diode
2 resistors
3 transistors
1 capacitor

Do we think the issue is with one of those 9 components? If so, not that I would want to do this as I wouldn't be learning as much, but could I just replace those 9 components and fix the issue?
What does the resistance show when test between A and B?
Do you see green line on the top side of the board showing that they are connected together?
Right now we are not getting any where until we get the resistance readings correctly.
Attached Images
File Type: jpg GND point for testing SHOWN TOP SIDE.jpg (326.5 KB, 5 views)
File Type: jpg PLUS and MINUS regulators circuit.jpg (88.8 KB, 7 views)

Last edited by budm; 08-06-2020 at 10:45 PM..
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Old 08-07-2020, 06:30 AM   #36
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

Quote:
Originally Posted by budm View Post
What does the resistance show when test between A and B?
Do you see green line on the top side of the board showing that they are connected together?
Right now we are not getting any where until we get the resistance readings correctly.


I will check again. Like I said you will have to be patient with me I am brand new to all of this


Your point about the good resistor reading more on the other leg makes sense. Maybe that indicates a short between those two points so the current would have an easier path to the probe than through the resistor?

I will try more readings today and keep looking for a ground. I am going to desolder those two spots you have marked as GND to see once and for all what they match up to on the other side of the board
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Old 08-07-2020, 09:19 AM   #37
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

OK I took some fresh readings and saw I was not reading my meter correctly.

So first, I wanted to check those zener diodes. I read that in one direction, Black lead to black side and red lead to brown side, I should get low resistance, and flipping the probes should be high resistance or even OL

So I tested Negative power path zenner diode in circuit, and was getting high resistance, like in the Mega Ohms, in both directions. So I decided to remove it to test it out of circuit, plus I needed to take it out to see the letters on it if I need to buy a new one

Out of circuit, it tested like this:
Black probe to black side, red probe to brown side: 6.5 Mega Ohms
Black probe to brown side, red probe to black side: OL

That sounds like it is wrong since it is high resistance in both directions? Also the letters "12V" are printed on the board underneath the zenner diode. the Diode itself has IN4752A written on it and either "5T" or "ST" written below it.

I then checked the other zenner diode on the positive power path in cirucit and was getting the following:
Black probe to black side, red probe to brown side: OL
Black probe to brown side, red probe to black side: 9 Mega Ohms and slowly dropping

Which also seems high in both directions. I'm assuming I got readings in the opposite probe orientation because of the positive and negative power channels

I continued testing the components along the V- path, the first resistor was .57 Ohms, the second resistor was .59 Ohms, and all three transistors measured .5 Ohms from E to C

So I put the diode back in, and rechecked the resistance from resistors to V- and V+ and paid more attention to the meter this time (near leg is the leg closer to V-/V+ pin)

Good resistor to V-
Near leg: ~5.45 Mega Ohms (fluctuated a little, 5.43 to 5.46 or so)
Far leg: ~5.45 Mega Ohms (fluctuated a little, 5.43 to 5.46 or so)

Good resistor to V+
Near leg: 7.1 Mega Ohms
Far leg: 7.08-7.09 Mega Ohms

Double checked resistor, it's read 179 Ohms. I am assuming I am not seeing a difference in the two legs because an 180 Ohm difference will be to small for my meter to show in Mega Ohms.


Burned Resistor to V-
Near leg: OL
Far leg: OL

Burned Resistor to V+
Near leg: 5.4 Ohm
Far leg: 180 Ohms
(Yes these were both Ohms not Mega Ohms. I checked 5 times)

Double checked resistor, it's read 174 Ohms.


All the readings from the GND area still read the same, rapid increase to 1.9 Kilo Ohms, then flash OL, then discharge from there. I tried measuring from V- and V+ to a black speaker terminal, and got the same thing, I looks at where the power came into the board and tried to trace that ground, the issue is the ground connects to the + and minus paths, and both of those each go through a fuse and then into a series of relays which are currently open (since the unit is unplugged and off) so nothing can get to ground.

I checked all around the V+ and V- for a ground but couldn't find anything that would give me a reading other than capacitor legs which just charged up and then discharged.

Quote:
What does the resistance show when test between A and B?
Ramps up quickly to 1.9 kilo ohms, then flashes OL, then shows 7.8ish kilo Ohms, it will slowly keep climbing, and if I take my probes off and then put them back on it will show it slowly going down. If I wait a few minutes I can repeat that process. I do see where the green is connecting them, to my untrained eye it looks like 2 capacitors in series.

Ideas for next steps?

Last edited by SluggerB; 08-07-2020 at 09:24 AM..
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Old 08-07-2020, 09:56 AM   #38
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

I also orders a zener diode pack and a pack of transistors off ebay, so in a week or so when they should up, I will have components on hand to replace anything along either of those V+ or V- paths
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Old 08-07-2020, 10:10 AM   #39
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

To test a diode you need a multimeter that has a diode test function.
To test a zener diode you need the same type of meter in the forward direction.
But in the reverse direction you need a multimeter that can supply enough voltage (12v in your case) for the test.
Very few normal meters can do that, the EEVBlog 121GW comes to mind.
As well as some variants of the cheap "transistor tester"
The easiest method to test a zener is with a current limited bench power supply.

Also please provide pictures of your meter testing points A+B provided by budm:
I think it will help clear allot of confusion in this thread!
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Old 08-07-2020, 11:03 AM   #40
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Default Re: Help diagnosing Pyle Receiver PTA66BT with burned resistors

I was going by this http://www.learningaboutelectronics....-a-zener-diode

I will have to take a video of testing those points since it is not a static reading, the numbers move. I'll do that later tonight
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