Ego 56V battery charger dead

[wtshyman]

Re: Ego 56V battery charger dead

My last kick at the Ego Power+ CH2100 charger.

Borrowed a bad battery, a good battery, and a known good charger from the owner of the subject charger.

No joy.

Repaired charger is totally inert even with a good battery in position - Kil-O-Watt says it doesn't even change from 40 mA current draw from the line. My cargo-cult substitution of a mystery FET from a junkbox for the mystery Q16 FET that was shorted G-S worked about as well as cargo cult spells always work.

From the good charger I learned there's no flashing lights or noise till a battery is installed (a transient flash of both LEDs happens if the charger has been unplugged for a while - my repair subject never does that). I also learned that there's about 3 1/2 volts from the temperature sense terminal to the -ve battery terminal on a good charger - my subject doesn't do that, either. I guess the power supply is never starting up and so not energizing the "low voltage" side to enable the charger to switch on. Since the UC28600 application note schematics don't closely resemble what Ego built here, I'm stymied to assess the start-up problem. And probing this board is no fun because of heavy conformal coating - I may just put everything in a bag and send it back to the junk heap it came from.

Here's a pic of C30 in its un-blown-up state. You can even read the PCB designation in the reflection of the heat sink.
I opened up the good charger and tried to check the rating on C30 - in this April 2017 version of the Ch2100, looks like it's a 330 pF capacitor rated 2 kV. Very hard to make out as it's buried behind the main filter caps.

[wtshyman]

Re: Ego 56V battery charger dead

I suspect U9, as mentioned above, may be at fault also. If it's a UCC28600 as listed earlier in the thread, I imagine I shouldn't read 0.5 ohms from Pin 5 (output driving the MOSFET) to ground.

.

In case someone stumbles on this thread:

I got U9 (28600 chip) off the board, using copious amounts of flux, solder wick and Kapton tape (Louis Rossman would be proud of me). But replacing it will only be for practice.

I still had 0.5 ohms to ground from pad 5. I found Q16, a surface-mount transistor on the traces side of the board, is shorted gate-to-source (assuming this is a FET). I can't make out any markings on this device. I may salvage a similar-size FET from a junk P/S or LED lamp but unless I have a breakthrough...this CH2100 has charged its last battery.

(Couldn't figure out where pin 1 was on the 28600 small outline IC. Today I found out that if they don't have a notch at the pin 1 end, look for the wide bevel on the case...pin 1 is at the left end of the package when the wide bevel is facing you.)

[wtshyman]

Re: Ego 56V battery charger dead

My parts orders came in today. I have replaced the bad transistor, resistor and capacitor and this evening powered up the charger through a 40 watt light bulb in case of short-circuits. I have 300+ volts on the transistor, but no activity at all. I don't presently have a battery to try charging - will there be any activity on the LEDs at all when first powering up?

I suspect U9, as mentioned above, may be at fault also. If it's a UCC28600 as listed earlier in the thread, I imagine I shouldn't read 0.5 ohms from Pin 5 (output driving the MOSFET) to ground. It's not clear to me how the MOSFEET is driven as there are an alarming number of SMD parts between U9 and the transistor gate. I can probably check for gross malfunctions of any SMD transistors I find (nothing blown up, but I can check for shorts ) but with no legible part numbers on these devices and no schematic available, I may have to tell the owner this charger has charged its last. At the transistor I read high resistance (I think 90+kohm) from gate to ground, so gate is not directly connected to pin 5 of U9.

Heavy conformal coating on this board is a drag for troubleshooting - even my needle probes that I recently bought are having a hard time making it through.

[wtshyman]

Re: Ego 56V battery charger dead

More on this old but useful thread.

I'm in the same boat. This thread has been very helpful. I'm hoping 470 pF at 2kV is good for C30 because that's what I've ordered based on this thread. Can't beat having a link directly to DigiKey's catalog for the resistor!

Ordinarily I'd be reluctant to tackle a switch-mode power supply but I had good luck earlier this year replacing a bad capacitor and blown transistor in a VCR (kids...ask your parents what a VCR was). Keeping my fingers crossed. The cost of parts is alarmingly low, it will be such a hoot to change out literally $5 worth of parts and get this $100+ charger working again.


Bill

[momaka]

Re: Ego 56V battery charger dead

I have the same issue and have noted similar damage to the same components.
I'd also like to pursue fixing it - should I continue on this thread to create a better repository of information on the Ego charger or would a new thread be better?

Up to you, really.

Generally, it's a good idea to start a new thread whenever you're in the process of troubleshooting, so as not to confuse anyone with information from previous poster(s)... but it seems like the original poster's PSU was fixed... and you say you have the same components failed... so in this case, continuing here should be OK too.

If you do start a new thread, though, make sure to link this thread so that the reader can piece information together, if needed.

Regardless of where you post, though, pictures of your board would be good to see.
Please use the forum's built in image attachment feature (and also note that images are limited to 3000x3000 pixels, so resize/crop images, if needed.)

[!sense]

Re: Ego 56V battery charger dead

I have the same issue and have noted similar damage to the same components.
I'd also like to pursue fixing it - should I continue on this thread to create a better repository of information on the Ego charger or would a new thread be better?

[braxton]

Re: Ego 56V battery charger dead

Thanks budm for helping me identify the parts that needed replacing.

[braxton]

Re: Ego 56V battery charger dead

I salvaged a 0.22 ohm resistor, 417pF 2KV cap and a 12N60 fet from some scrap boards, and got the charger to come to life with the lights lighting up and no bangs or poofs of smoke.
Probably will not test further until I order the proper parts from digikey.

Well it's working fine and charging with my franken-parts installed.
I am debating whether I should even order replacements. I suspect the cap and resistor will be fine; less sure about the fet since its rated for 12A and 600V vs the original 18A 650V.

[budm]

Re: Ego 56V battery charger dead

I tried gently scraping the coating off and using alcohol on the U9 chip but still could not read anything. At one point I thought I could read the number 28 but not sure.
Here is a picture of the resistor. The color bands appear to be brown-grey-silver-gold

0.18 Ohm (Brown/Grey/Silver)

[braxton]

Re: Ego 56V battery charger dead

I salvaged a 0.22 ohm resistor, 417pF 2KV cap and a 12N60 fet from some scrap boards, and got the charger to come to life with the lights lighting up and no bangs or poofs of smoke.
Probably will not test further until I order the proper parts from digikey.

[braxton]

Re: Ego 56V battery charger dead

would this be a suitable resistor replacement?

https://www.digikey.ca/en/products/d...mSeq=332340179

[braxton]

Re: Ego 56V battery charger dead

Its possible the U9 chip might have the following written on it:

28600D
96M
A6N2

[braxton]

Re: Ego 56V battery charger dead

Also, the mosfet was tested after removal from the board, and was shorted on the outer pins.

In the you tube video I posted in the first link, in the comments section, someone indicated they had a defective C30 (same blown cap) as well as a blown Q16 and D22 (close proximity to U9), but the latter two components don’t look blown on my board.

[braxton]

Re: Ego 56V battery charger dead

I tried gently scraping the coating off and using alcohol on the U9 chip but still could not read anything. At one point I thought I could read the number 28 but not sure.
Here is a picture of the resistor. The color bands appear to be brown-grey-silver-gold

[budm]

Re: Ego 56V battery charger dead

Resistance reading on two outer pins of the fet is 1.4 ohms- same reading when I touch two leads of multimeter together.

Well that means you have shorts between Gate and Source, remove the that MOSFET and retest it off the board.
More than likely that U9 is damaged too.
What is the color bands of the R52?
BTW, you have have to try cleaning the top of IC with Alcohol to see if you can read the prints on top of it.

[braxton]

Re: Ego 56V battery charger dead

Resistance reading on two outer pins of the fet is 1.4 ohms- same reading when I touch two leads of multimeter together.

[braxton]

Re: Ego 56V battery charger dead

I’ve attached a few more pics of the resistor I tested. Shown with yellow arrow from the top of board and purple x’s from the bottom. Yellow x’s and red arrow on bottom of board are the location of the blown cap.

It’s not possible to read anything on the top of u9 unfortunately.

[budm]

Re: Ego 56V battery charger dead

https://www.badcaps.net/forum/attach...5&d=1594741646
What is the P/N of the SMPS IC U9?

[budm]

Re: Ego 56V battery charger dead

I cannot see R52 on the top side of the board due to the picture is not clear enough to read the designators as printed on the board.
Show us good clear pictures of R52 and where it is located on the board. Source resistor should be < 1 Ohm.

"But there is continuity between both outer legs on the fet." What is the resistance reading using Ohm mode?

[braxton]

Re: Ego 56V battery charger dead

The mosfet is 18n65. I had to remove it to get the number.
There is no continuity between the center leg and both outer legs.
But there is continuity between both outer legs on the fet.

Resistor R52 (large resistor closest to blown cap) has a reading of 5.7k when removed from the board.