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Dead DX2517

I ordered another diode bridge about an hour ago but it won't be here for 6 days. It is not a common one, and I did not want to get one from the last supplier in case they have a bad batch.

In the meantime I was wanting to see if I could bypass it and get power to somewhere and check if the radio would come on or not, that is all
 
TruckerKevin said:
But, just a question. Why would I not be able to connect it to the rc dc terminals? Isn't that what the rectifier does, supply voltage to the power board?
Click to expand...

Well, in a word, yes ......
But I'm thinking there is also a problem with the voltage regulator circuitry.
I agree with what Robb is saying above.
 
TruckerKevin said:
I ordered another diode bridge about an hour ago but it won't be here for 6 days. It is not a common one, and I did not want to get one from the last supplier in case they have a bad batch.

In the meantime I was wanting to see if I could bypass it and get power to somewhere and check if the radio would come on or not, that is all
Click to expand...
You can do that. Just be sure to mark the wires leaving the radio's supply board and KNOW which ones are + and - ; that goes for the board too. You DO NOT want get these wires out of phase when you put it back together - or else you will fry that radio. Make notes and mark one wire and the board too.
 
2517power.png
When you attempted to wire something to the on/off switch, was that a jumper wire, or an external power supply?

Have you disconnected the regulator board EPTOSSB62A, completely, it looks like if you goto the power switch, you are not excluding the EPTOSSBB62A board from the circuit.

Did you also attach the negative lead if it was an external supply?
If you use an external regulated power supply at around 13.8-14.1 Volts, and disconnect the factory power board from the circuit, you should be able run the radio off an external supply granted the ground and positive wires are connected at the correct place & assuming nothing else is wrong...
 
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If those diodes are all forward biased, they tested good (at least in the old rectifier).

My multimeter is very old, but it does have a diode setting. I get about .440 to to .502 across all 4, and no reading the opposite way (my meter does not display ol)

LeapFrog, I tried running the ground wire from the external power supply to the negative post of the rectifier first, then to chassis ground. As far as positive goes, I tried the power switch but that was all. I dont want to just run current everywhere, like everybody thinks im about to do lol.

I am also suspicious that I have a short elsewhere. I got thios radio with that popping in the first video, and I found D107 burned up. I replaced the diode with the correct value, powered it on and still heard it pop then soon after the whole thing shut off, and here I am today.
 
TruckerKevin said:
Okay that makes more sense now. lol

Across the transformer leads I get 19.60 on the ac setting

But where I am getting confused Robb, is I only have 1 dc output from the rectifier, the other is ground.

What I am saying is, you said measure the dc voltages across the 2 dc terminals coming out of the rectifier, but they consist of a positive and a negative
Click to expand...
Yep; test those two. There should be about 17v DC. Remember; into the rectifier is AC voltage, so test for AC mode on your meter. OUT of the rectifier is now DC; so test in DC mode on your meter.
 
TruckerKevin said:
Yes sir, I did just that. I got 19.60 out of the transformer in ac mode, but in dc mode out of the rectifier I get zilch. zero. nothing
Click to expand...
You said that the rectifier that you tested each diode in - if you did it correctly - it was reading that each diode was good. If so; then use that diode bridge.

The is nothing mystical about this part. It is just four diodes; that's it.

I hope you are testing the rectifier output in DC mode - and not to ground - but to the two leads on the rectifier that are not being used for AC in from the xformer.
Got it?
 
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TruckerKevin said:
If those diodes are all forward biased, they tested good (at least in the old rectifier).

My multimeter is very old, but it does have a diode setting. I get about .440 to to .502 across all 4, and no reading the opposite way (my meter does not display ol)

LeapFrog, I tried running the ground wire from the external power supply to the negative post of the rectifier first, then to chassis ground. As far as positive goes, I tried the power switch but that was all. I dont want to just run current everywhere, like everybody thinks im about to do lol.

I am also suspicious that I have a short elsewhere. I got thios radio with that popping in the first video, and I found D107 burned up. I replaced the diode with the correct value, powered it on and still heard it pop then soon after the whole thing shut off, and here I am today.
Click to expand...

TruckerKevin, ok I have a suggestion to go along with what ShadeTreeMechanic said, try measuring any battery cell that you may have laying around, like a 9V or a AA. I just want to make sure your meter is reading DC, a battery should at least give you an indication if the meter is good-to-go, or not.
 
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Sorry for the delay guys.

My meter works great in DC mode. I get 9 volts on a 9 volt battery.

I put the old rectifier back in. Still dead. 19 Volts going in from AC (in ac mode across terminals), nothing coming out. (In dc mode with black lead to ground and red lead to positive)

This is the craziest thing I have ever seen.

What else can it possibly be?

This whole radio gets its power off that bridge rectifier does it not?

If I have 19 AC volts going into it, and 0 DC volts coming out, it has to be dead. There is no other logical answer as far as I can tell.

Now here is something that may or may not be.

When I measure DC volts at the + red terminal, my meter doesn't just remain at 0. It goes to 1 .

Not 1 volt, mind you. Just a far left -1, like its telling me there is a negative or shorted charge or something

This may sound confusing, but if I tried to measure voltage on a radio that is not powered on, or not supplying anything on that particular terminal, it just stays at 0. Naturally. Because there are 0 volts.

But this goes straight to 1 . Like its going to ground or something. (I tested ohms from positive to chassis ground to check for dead shorts but got nothing) Hopefully it means nothing.
 
After I checked the 2 AC lines from the transformer I switched my meter to dc mode, then I put the black lead to the ground post on the rectifier and the red lead to the positive post on the rectifier. When I got zero, I moved the ground to chassis ground to make sure.

Then I just double checked it with my oscilloscope. I put the probe on the ac lines and hit autoset, got a great wave pattern. Moved over to DC line and got nothing, even after auto set and manually adjusting my volts per division. I get a good wave pattern from the AC volt lines Nothing from the DC line. Just a flat line.
 

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