Short burned generator PCB. Can this be repaired?

[Kurtatron]

I was testing a 4200 watt craftsman generator that was having performance issues. Wires came in contact with the frame of the unit. The engine cut out immediately.

Big spark flashed next to me.

Stupid, I know. Should I just trash this thing? Replacement board is $250.

I don’t want to spend that.

I have no experience fixing pcb. I own a soldering iron for repairing wires only. This board does look very basic. It’s from 1995.

What do you think?

 

[JMJNet]

Is it still working?

 

[chemman]

Without being able to see a couple of circuit board "landmarks" such as a couple of mounting holes or where a wires connector connects to the circuit board, it will be hard to locate parts relative to the burn mark(s) on the solder side of the circuit board.

However if the oblong solder area in Picture 2 which is marked P2 is the same as the oblong solder area shown in Pictures 1 and 3, I would suspect the black diode with the letter N immediately above the silver band as having blown internally. Actually, I am surprised it did not blow itself apart.

You can test it using an ohm meter - either analog or digital. First unsolder at least one of the wire leads from the circuit board, and then put one test lead from the ohm meter one one lead of the diode and the the other test lead of the ohm meter to the other end of the diode. With the ohm meter set to the, say the X1 position, you should see 0 ohms or an extremely high number of ohms (or infinity). Then switch the test leads around and you should see an extremely high number of ohms (or infinity) or 0 ohms. If you see 0 ohms both ways, then diode is shorted. If you see a high number of ohms (or infinity) both ways, the diode is blown.

Now, if the diode is bad, unsolder the other side of the diode from the circuit board and read the characters printed on the diode. You should see something like 1N4001 or 1N4005 or 1N5401, etc. Those will be the part number of the diode.

Just as an FYI, the 1N4000 series diodes can handle 1 amp of current and the 1N5400 series diodes can handle up to 3 amps of current.

I will say, the electrolytic capacitor located at the bottom of the circuit board in Picture 2 that is bent towards the left, appears to be bulging (I think the capacitor has the letter & number combination of C3 located above it and adjacent to the resistor on the circuit board) is either bad or is going bad due to the bulging. If you unsolder it, the voltage rating and amount of capacitance should be printed on it. Also note is there is a row of minus (-) signs going along one side for positioning.

In the picture I have included I circled the suspect diode in white and the suspicious capacitor in yellow.

Hope this helps and if you need help in finding replacement parts, just let me know the numbers you get off the old parts and I'll be more than happy to point you in the right direction.

Good Luck!

 

[Lubener]

You can substitute jumper wires to take the place of the burned traces on the board. However, if some components were ruined by the short , you are better off replacing the entire board. It's not worth fixing. I have a feeling that some components were also damaged along with the board damage.

 

[chorty]

if it's a single layer pcb, for sure.

should take a meter and check every component though. just because they didnt pop doesn't mean they're good

f it's from 1995, good chance it'll be cheap, but difficult to find.

seems all the good simple stuff is NLA back from 20 years ago. big brother wants us to buy newer more complicated garbage.

 

[Nessism1]

Yeah, the problem with a job like that is isolating the fault area.

I recently cracked open a Makita battery charger after it stopped working. Found a shattered fuse and popped capacitor. Simple fix, I thought. Paid $12 for a cap, and $6 for a pack of fuses. Repair went fine, but as soon as I plugged it in, the fuse popped again. I gave it the old college try, but failed.

In the end, I found a nice low mileage Makita charger on ebay for $15. Should have done that in the first place...

 

[supton]

seems all the good simple stuff is NLA back from 20 years ago. big brother wants us to buy newer more complicated garbage.

Not sure why you think it is the fault of the gov? no computer motherboard is going to work as single layer pcb. More complex circuit boards are about performance and packaging.

 

[nomas]

You said the generator was having performance issues ?

 

[AZjeff]

So you're into a used charger over $30 and new ones are $20-40 online. Been there too, just can't not try a fix.

In the end, I found a nice low mileage Makita charger on ebay for $15. Should have done that in the first place...

 

[Astro14]

So you're into a used charger over $30 and new ones are $20-40 online. Been there too, just can't not try a fix.

Makita chargers are closer to $100, new. Not $20-$40, unless you’re shopping knock off junk.

 

[chorty]

Not sure why you think it is the fault of the gov? no computer motherboard is going to work as single layer pcb. More complex circuit boards are about performance and packaging.

Its difficult to find parts for simpler equipment

 

[Marcozi]

Its difficult to find parts for simpler equipment

Try www.mouser.com.

 

[chorty]

Try www.mouser.com.

Its the new RadioShack, on steroids.

I highly doubt I'll find oem PCBs for my old equipment.

 

[football]

Sell the generator for parts, buy a new one. Thank me later. It’s a disposable Chinese generator. Not a $5000 Honda worth fixing.

All these low cost generator are all … low cost. They are disposable and not built all that well.

I own about 4-6 generators at any one time (I like small engines and own a ton of them) and I think the average home owner should sell off their generator and replace it every 8-10 years. Assuming it’s a cheapy disposable.

Do the math. You can get a new champion generator for like $600-$700. Sell the old one for $500 and you get a new generator (with a new powerhead, new fuel lines, clean gas tank, brand new clean carburetor, every couple years for an out of pocket of $100-$200. It’s a no brainer.

 

[Kurtatron]

Sell the generator for parts, buy a new one. Thank me later. It’s a disposable Chinese generator. Not a $5000 Honda worth fixing.

All these low cost generator are all … low cost. They are disposable and not built all that well.

I own about 4-6 generators at any one time (I like small engines and own a ton of them) and I think the average home owner should sell off their generator and replace it every 8-10 years. Assuming it’s a cheapy disposable.

Do the math. You can get a new champion generator for like $600-$700. Sell the old one for $500 and you get a new generator (with a new powerhead, new fuel lines, clean gas tank, brand new clean carburetor, every couple years for an out of pocket of $100-$200. It’s a no brainer.

No, it’s a Generac 7.8hp motor that was made in US. Generac alternator was also made in US. It’s old.

 

[AZjeff]

Makita chargers are closer to $100, new. Not $20-$40, unless you’re shopping knock off junk.

From the Makita Store on Amazon. This is a knock-off? With a battery they're $100.

 

[supton]

Its difficult to find parts for simpler equipment

Not much demand for the older stuff, plus the newer stuff is different. Lithium ion batteries are complicated beasts, with fancy charging circuits. Don't get me wrong, I like old stuff, have some of it, but some of the new stuff just works that much better. Even if it has to be replaced periodically.

Its the new RadioShack, on steroids.

I highly doubt I'll find oem PCBs for my old equipment.

More like on a combo of coke and speed and something else. Ratshack barely carried anything in the couple of decades that I was old enough to shop there. Maybe they were great eons ago. More of a Digikey guy myself. I've shopped at Mouser a few times personally, but at work, our BOM's carry MPN and the Digikey p/n. Miss the old parts catalogs that you could thumb through, keep an old Newark around for that, but everything's all digital now.

Never gone shopping for PCB's... not sure if anyone stocks blanks. Assemblies, sure, but pricey of course. HASL boards should be good to store for a long time but I think it was only recently that ENIG got good enough to have long shelf life (mind you, it has to be sealed up properly for storage).

 

[Marcozi]

Its the new RadioShack, on steroids.

I highly doubt I'll find oem PCBs for my old equipment.

But you can find the components.

 

[zzyzzx]

That board looks fixable to me.