Author Topic: NOCO GB70 repair help  (Read 4447 times)

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Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #25 on: October 09, 2024, 04:05:00 pm »
You were right, i have ghost charge effect,it charge all night on that round charger from cigaret lighter plug and nothing, but when i put it on USB it charge on 100% and green light is on.  After i connect it to car battery, charge % leds starts to flash from 25-100% but nothing happen. I guess i have to hear some relay. Those 2 big ones on negative terminal if i remamber right.
 

Offline eurgenca

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Re: NOCO GB70 repair help
« Reply #26 on: October 10, 2024, 06:28:59 pm »
Check pin 26 of CPU (from memory, will confirm tomorrow) resistance to GND and write it down.
 

Offline eurgenca

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Re: NOCO GB70 repair help
« Reply #27 on: October 11, 2024, 12:58:34 pm »
No sorry pin 27.
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #28 on: October 13, 2024, 02:12:04 pm »
I measure it and take a picture, not sure if that ok or not but i guess its not.  :-DD :-DD
I mark arrow where did i measure, just in case i did miss PIN 27.
 

Offline eurgenca

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Re: NOCO GB70 repair help
« Reply #29 on: October 14, 2024, 05:55:58 am »
Well, this is the end, my friend.
Your CPU is busted. You will confirm that by lifting this pin, and if resistance is still low on CPU pin, then...
Here is a chance to invite other members. I don't ovn holtek programmer if someone have we can try to read content if not locked.
 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #30 on: October 14, 2024, 06:33:18 am »
Well, this is the end, my friend.
Your CPU is busted. You will confirm that by lifting this pin, and if resistance is still low on CPU pin, then...
Here is a chance to invite other members. I don't ovn holtek programmer if someone have we can try to read content if not locked.

I have a Holtek programmer but if you look closely at the circuit board pics in the early posting, notice the lack of programming headers that is present on most all of the other NOCO jump pack line.  On the GB70 it's an OTP MCU so even if...The R series MCU in question is not for sale to the public and is only available to the OEM vendor (AFAIK).

I sure felt bad about being the grim reaper about the MCU but when you said to check the input protection diode I sure was hoping it was the only issue as this would have been such a simple fix.  I am curious as to why you checked pin 27 for resistance.  Typically that pin (PA5) is the latching circuit in the power on scheme on some of the other jump pack models.  From what I see on the GB70 it may be different.



Jerry
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #31 on: October 14, 2024, 05:12:11 pm »
Im not the expert in this stuff but there is something about it when somesaid its dead and i revive it.  It gives me satisfaction, its wierd i know but i like to fix stuff. And learn in the proces . If that 3 pin connector is responsible for those two big relays  it was logically to search from end of the problem to the top, if iyou know what i mean.  Maybe im wrong but continuity test on D17 beeps in both direction. 

And one crazy thing is if i put on continuity test and probe Lower left and upper pin on Q15 the big relay clicks.

Is that strange or not?
 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #32 on: October 14, 2024, 07:12:56 pm »
Not.  Disconnect your relay plug and then check D17 which is your flyback diode for the relay coils.  Using the continuity test on Q15's base you have activated the transistor that drives the output relays.  As a general rule I do not test for continuity on live circuit boards.  Randomly activating transistors can cause bad outcomes unless you fully understand the circuit.

Back to the problem at hand and since you are exploring you could do a resistance check across R305.  It should read 4.7K.

If you were closer I would be glad to go over that board in the remote chance there is something we are missing here.  The true test is as @eurgenca stated.  Carefully with power disconnected lift pin 27 and recheck resistance.

Jerry
 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #33 on: October 15, 2024, 04:15:30 pm »
Can you HOLD OFF on any more exploring of this circuit board until I test some things on my end. Pin 27 goes to R305 and P27 of the daughter board connector.

There is a chance that the short to ground at pin 27 is a problem is on the daughter board.  Your MCU may be OK!

I am going to remove the daughter board on the one that I have and trace that circuit down.

I will get back shortly and let you know what I find.

Of course the next question is are you capable of removing the daughter board?

Jerry
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #34 on: October 15, 2024, 04:25:06 pm »
I can hold my exploring. But i didnt tell one maybe crucial info, when i did explore with probing the Q15, i turn the booster on and than i probe again, when it click i have voltage on clamps around 16.3v and the leds flash from 25 to 100%.
Maybe this info is good maybe its useless but just in case. 
 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #35 on: October 15, 2024, 05:07:20 pm »
I can hold my exploring. But i didnt tell one maybe crucial info, when i did explore with probing the Q15, i turn the booster on and than i probe again, when it click i have voltage on clamps around 16.3v and the leds flash from 25 to 100%.
Maybe this info is good maybe its useless but just in case.

That kind of voltage is very concerning.  That would mean you have overcharged this battery and each cell is at 5.4V.  Please confirm the individual cell voltages in the three cells.

Jerry
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #36 on: October 15, 2024, 06:01:36 pm »
Guess bad battery was in that other device.
All 3 cells are at 4.15V. guess that 16.3 was some kind of a mistake in measuring device
 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #37 on: October 15, 2024, 06:38:28 pm »
So you have been able to charge the battery. 

Start from the beginning.

1. Press On/Off button Unit should turn on and all four battery indicator lights should be lit all the way up to the green led. You should also hear a click from 12V output transfer relay that's on the board.

2. Press and hold override switch for 3 seconds. You should hear a significant click and the battery indicator lights should repeatedly flash from 25% to 100%.  Then check voltage at clamps and it should be around 12.3V or so.

3. Press override switch. Flashing Leds stop and unit should return to the original on state described in step 1.

4. Press On/Off button Unit should turn off.

5. With the unit off Press the light button Unit should turn on with all battery leds lit and the light should turn on.

Do these things and nothing else and tell me the results.

Jerry
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #38 on: October 16, 2024, 08:17:10 pm »
Yes battery can be charged but only on USB port not,barrel port but thats not important as long as i can charge it anyhow.

so. lets go
1. Works
2. works
3. not work. when not in override mode on clamps i have 0.7V when override mode i have 1.6V, not good.
4. it turns off as it should.
5.Led works, and every variation of LEDS, dimed and strobing and stuff

I did check resistance of R305 and it was 4,69k ohms, i guess that is ok.
 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #39 on: October 17, 2024, 12:58:23 am »
You answers to item 2 and 3 seem a bit contradictory.

Starting with item 2.  Can you confirm this is what happens.  While unit is on and with nothing connected to the clamp you press the override for 3 seconds - this will cause the two output relays to engage with an audible click.  At this point measure the voltage at the clamps and it should be 12.3 or so.

Your response to item 3 confuses me because you mention that in override mode the voltage is 1.6V but in item 2 you say it "works" which would mean the voltages at the clamps are 12.3 like I stated in item 2 test.   It would be helpful to know if the override is working correctly.

When the override is engaged all battery power transferred directly to the clamps via the two relays.  When not in override there is close to no voltage at the clamps. It's that simple.

If you could clarify this confusion that would be helpful. 

As for further testing measure the resistance between R305 on the side closest to the number 5 and the main battery ground above R106.

Take this resistance measurement with all JST plugs disconnected and then with just the relay plug connected. 

Remember the battery balance plug and the relay plug are the same. Don't mix those two up ;)


Jerry
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #40 on: October 17, 2024, 04:34:52 pm »
Sorry my bad, it was late and kids and wife was crazy around me so i write it wrong. i ment works on 2.nd statment as it works that  it wants to start override, i thought that button works when i press it and it goes in override mode, but nothing after happen. Leds flash but no real output.

Ill check what you suggested and post again. 
Sorry for confusion   
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #41 on: October 17, 2024, 05:58:41 pm »

Remember the battery balance plug and the relay plug are the same. Don't mix those two up ;)


You mean they are not the same? or Im confused now   :-DD

I did measure with all plugs dissconected. 4.52Mohms, and with JST relay plug connected it said 0.8ohms.


 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #42 on: October 17, 2024, 06:27:59 pm »
With all plugs disconnected:

Edit to add:  Measure the resistance across D17 ( this should have already been done per reply #32)

Measure the resistance between the red and white wire on the relay pair.  Then measure the resistance across the two parallel bus bars on the relays.

Measure the resistance across the following resistors - R74, R75, R76, R77, R79.

Just list the values if you like.

Then measure the resistance between all the pins on Q14.  I'm not concerned about specific values.  Two of your measurements should fall under .5 M ohms range and  one around 10k.  Anything in the low ohms range would indicate an issue.

Jerry
« Last Edit: October 18, 2024, 02:54:27 pm by jerryk »
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #43 on: October 22, 2024, 08:06:11 pm »
R74 - 3.194 kohm
R75 - 3.195 kohm
R76 - 10.07 kohm
R77 - 4.7 kohm
R79 - 246.9 kohm

Q14 - 2 pin next to the R74 and R75 are at 3.195 kohm
Others are 0.531 mohm and 238.1 kohm.

 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #44 on: October 22, 2024, 11:08:01 pm »
Even though this is in circuit testing they should read sort of close to the value on the resistor with the exception of R79.
This is about how it should read.  This can vary between multimeters and switching the probe polarity can effect the reading.

R74 - 4.7 kohm
R75 - 10 kohm
R76 - 10 kohm
R77 - 4.7 kohm
R79 - 245 kohm

Are you saying 0.531 milliohms here?  Or did you mean megaohms?
Others are 0.531 mohm and 238.1 kohm.

Again with all plugs disconnected -
Did you test for resistance across D17?  You can also do a diode test in circuit here too.

If you can confirm the milliohms vs megaohm question. If the answer is megaohms AND D17 tests as a functioning diode the next test is to plug all plugs back in, turn the unit on, engage the override/boost to you get the progressive leds flashing.  At that point test the voltage at the test point next to R74.  It should read 3.3V.

The underlying assumption here is that when you engage the override/boost button the battery status leds flash progressively but there is no click at the main relays and no transfer of power to the clamps.  Pin 11 on your MCU controls the base of Q14 thru R74.  When Q14 turns on it the powers Q15 that drives the main relay coils.  We are just trying to see why this circuit is not functioning correctly.  Keep in mind that this could still travel full circle back to the MCU but there is a possibility that Q14 has an issue or D17 might be shorted.

Jerry
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #45 on: October 23, 2024, 03:54:31 pm »
I think its megaohms its big M on the multimeter.
But maybe im wrong, il take a picture and post it.

I test it all with all plugs disconnected
...Maybe im wrong but continuity test on D17 beeps in both direction. 


I did measure D17 few posts before. and it seems like its bad also. Correct me if im wrong.
So far i didnt get diodes i order from the internet, but ill try to solder regular one not SMD just for testing only and let you know.

 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #46 on: October 23, 2024, 04:57:56 pm »
I did measure D17 few posts before. and it seems like its bad also. Correct me if im wrong.

Possible confusion on my part.
In your earlier post you were testing things with the relay plug engaged since you activated Q15 via a continuity test and the relay engaged.  As long as all plugs are currently disconnected and D17 measures as a low resistance short in either direction the diode D17 is faulty.  If this is the case, then you can replace it with a 1N4148 or similar.  Keep in mind it's the flyback diode for the main relays and needs to be installed before you attempt to activate those relays.

Jerry
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #47 on: October 24, 2024, 07:44:58 pm »
Diodes finally came from post office. Ill change both ones and post if its working or not. 
 

Offline AN86Topic starter

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Re: NOCO GB70 repair help
« Reply #48 on: October 31, 2024, 09:17:50 pm »
Got strucked with feaver so i was offline for a few days.

I did change diodes but still the same. No right signal on that transistor that engage the big relay.

 

Offline jerryk

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Re: NOCO GB70 repair help
« Reply #49 on: November 01, 2024, 05:32:13 am »
It would be helpful if you would refer to any diode, transistors or other circuit component by the silk screen label on the board.

You said you replaced "diodes but still the same".  Can you tell me which diodes you replaced and what diode did you use as the replacement?  The only defective diode I'm aware of in this discussion is ZD2 which is a 5V1 Zener diode.  I'm not sure what other diode you replaced.  As for ZD2 you have already replaced it with a 5V1 (axial lead) diode so putting the original smd version in it's place would do nothing.  It's just a protection diode for the MCU and you could remove it and your circuit would still not change in it's behavior.

As for "No right signal on that transistor that engage the big relay."  If you checked the test point near the label R74 after holding down the boost/override button for three seconds and did not see 3.3V then you need to remove R74 and try that test again.  The purpose of this test is to completely isolate pin 11 from any possible ground faults down stream of the pin.  If you have R74 removed and after a three second press of the boost/override switch you get the flashing leds from 25% to 100% but no 3.3V at that test point then I cannot see any other fault possibility than the MCU.

Good Luck - Jerry

 


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