Makita DC18RC Charger Repair: Identify IC1 (1D12308), R91 Resistor & D14 Diode Replacement

Question

Hello. I have a damaged charger as in the topic. The R91 resistor and the D14 diode were burned out. After replacing them, the charger still does not ...

miecho18 · Answer

What is the housing of this chip?

andsab · Answer

S08 housing.

Mario 814 · Answer

I am just repairing such a charger. In addition to the R91 2R4, D14 zenerka 30V, I also had the Q3 KF2N60 transistor and the R29 2R2 resistor. So far I have ordered parts, let's see if it helps. IC1 is from the main converter and damaged components belong to the auxiliary converter.

Anonymous · Answer

Buddy, there's nothing to think about here. And it does not only apply to this device, but to all impulse power supplies, chargers, converters ... We now have a PLAGUE of damaged lumber Made in China. All of this is done deliberately to break. What you have is the same, do not count on a miracle and do not think, just check all semiconductors and then the elements one by one, because there will be a lot of it horny there. There is no option that the resistor or diode is on and the transistors are not. See the post above mine, your friend is writing what he has fallen out, and it's not all probably yet. All these power supplies (because this is ordinary rubbish is made of just about anything, so that the Chinese would have too much for these pieces for them later) are made for one "hoof", the construction is sometimes confusingly similar to many devices. Look for what else you have stoned because then when you put in good pieces, the smoke will only fly out of them when something else will be compact.

gumisie · Answer

@andsab take some clear photos and post them here on the forum. Maybe it will be easier for you to help.

Mario 814 · Answer

After replacing the damaged elements, the converter started, but instead of the expected 12V, I got only 1.95V at the output. After a long fight, it turned out that the culprit is the SMD C17 6.8nF capacitor. After replacement, 12.4V appeared at the inverter's output, the charger is working properly :D

PS. If I need someone, I have a handwritten diagram of this converter.

gumisie · Answer

So before you close a topic, it would be advisable to include it here. Regards.

Mario 814 · Answer

I present a hand-drawn diagram of an auxiliary converter.

magnum1978 · Answer

Hello, I have a Makita double charger has stopped working, there are no damaged elements, i.e. the theoretical plate looks the same as in a single 18, maybe someone will suggest something

Mircio82 · Answer

Hello, I also have a Makita DC 18RC S double charger. One side is working properly, ie it is charging the battery, while the other side is not charging. After unscrewing the charger, I found that the F101 T4AH AC 250V fuse was blown. After inserting a new one, this one is also burned, which means there must be a short circuit somewhere. I will put a few photos of my charger here, maybe someone will say visually why it is not charging.

Mario 814 · Answer

Mircio82 you should check the rectifier bridge (diodes), the Mos-fet transistor and the auxiliary converter circuit for a drain-source short circuit. Items marked in the photo.
magnum1978 both sides not working? Fuse as for Mircio82 working? High voltage after bridge rectifier present?

Mircio82 · Answer

Hello Mario814, thanks for the advice, what I can check only in the problem that I do not know how to do it, I only have the simplest electrical meter at home. It's nice if you write step by step how to check the elements you indicated. Regards

Mircio82 · Answer

Mario, I checked the transistor and bridge today, but I don't know how to check the third element. There is little information on the Internet on how to do this. Maybe it will help, but I did not write that the fuse burns without the battery attached.

Mario 814 · Answer

Hope you checked these items well. The Mosfet bridge and transistor is best checked by setting the meter to measure the diode. In the bridge we connect the positive end of the meter to the "-" bridge, and the negative end to one and then the other "~" terminal. The output should be about 0.45 - 0.6 V. Then the meter minus to the "+" bridge, and the meter plus to one and then to the other "~" terminal of the bridge. It should work out similarly. Also check that there is no short circuit between the "+" and "-" jumper and the "~" and "~" terminals. The transistor is checked for a short circuit between the drain and the source. Connect the meter plus to the "S" source, and the meter minus to the "D" drain (at the Mosfet transistor with N channel). The output should be about 0.3 - 0.5 V. To be sure, you can check the transistor's Datasheet to see if it has a diode between the drain and the source. There should definitely not be a short circuit there. As for the third element, find a Datasheet for it and identify which pins have the drain and the source of the transistor keying the converter and measure as above. Picture with an example bridge and Mosfet transistor. Good luck.

Anonymous · Answer

This can be done without combination and with the simplest method of logic. My friend Mircio82 , first of all, there is such a method for short-circuit diagnostics in this type of devices. Instead of a fuse, you give a 230V bulb with a power of about 40-60W, turn the device on and see how the bulb shines with full light, it is a short circuit in the device - SIMPLE AS A CEPA CONSTRUCTION. Secondly, when you already have the above-mentioned bulb system assembled, it is even easier when you suspect the damage sector. You turn on the system still with the bulb instead of the fuse and what do you see? Well, it still shines - you know the short circuit is still there, you suspect this "third element", disconnect the 230V power supply and DISCHARGE CAPACITORS ON THE PRIMARY SIDE - it's not fun, because these voltages are dangerous to life and health! . Remove this chip, turn the chip on again, if the bulb is off, it means that the short circuit was in this "third element" and that's it. As the bulb is still on, you are looking for a method of eliminating the next element on which this is a short circuit every time you turn off the 230V voltage and discharge the capacitors - EVERY TIME .

gumisie · Answer

Gentlemen. The author of the topic, founded: 12 Sep 2017 15:24 and is still "silent". Are we not violating the electrode regulations? :cry: Regards.