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Alan Reynolds
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That's them. Motorolo MJE13009. My ultrasonics kept blowing the MJE13007's so I uprated to the 13009. The resistors are usually a long square white ceramic type that sit in the collectors and I suppose they act like a fuse as they always go with the transistors. I've always suspected that my machines were 110v by the look of the design on the board and the Chinamen just altered a few components to get them to tolerate 220v. Heat sink compound is a must if you replace them.
graffian
Seer unto the end of his beard
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I bought my US cleaner not working.
The machine heated up and had display. The two output transistors were gone, as checked in circuit.
I pulled them out and they were dead. I replaced them and it worked and sounded like it was pretty angry.
I used it for a year or so and one day it got quiet and then stopped working. The same transistors had gone
and the .33 ohm resistors had gone. If a pair of C4237 transistors will do let me know, I had to buy a tube of 10.
The machine heated up and had display. The two output transistors were gone, as checked in circuit.
I pulled them out and they were dead. I replaced them and it worked and sounded like it was pretty angry.
I used it for a year or so and one day it got quiet and then stopped working. The same transistors had gone
and the .33 ohm resistors had gone. If a pair of C4237 transistors will do let me know, I had to buy a tube of 10.
thanks mate
, but I've gone ahead and bought them, same bought a box easier... already have the resistors, fuses and transitors are on the way... The only thing I didn't think of was the heat sink compound
, will have to go back and reorder that....thanks @Alan Reynolds well spotted never thouught of that...
, but I've gone ahead and bought them, same bought a box easier... already have the resistors, fuses and transitors are on the way... The only thing I didn't think of was the heat sink compound, will have to go back and reorder that....thanks @Alan Reynolds well spotted never thouught of that... right all the bits arrived so went to have a play last night, and came to an abrupt stop... the other bits are right except the resistors I had in the kit. Now if I understand correctly, I have a 46 or maybe a 47k Ohm resister on the board, and I also have a replacement 47k Ohm in a kit, but when I got the bits side by side, I'm not convinced. The band colours aren't anything like each other, and the new one seems to be half the physical size? are they different types? or are they compatible. as you've probably guessed electronics isn't my field.....
I presumed a resistor was just a resistor, but maybe not... It's maybe not an issue, but before I wade in, wanted to check with those that know, are they the same or if not what do type do I need..
any thoughts?
original
new
I presumed a resistor was just a resistor, but maybe not... It's maybe not an issue, but before I wade in, wanted to check with those that know, are they the same or if not what do type do I need..
any thoughts?
original
new
thanks mate, so was a good job I checked. Thought it might be, was sure the capacity rating was right, it was the physical size that concened me most, wasn't convince it was up to it...
So I'll need to order them in, that's fine, but, from that table, I'm struggling to figure out what I need wattagewise. Don't know what the voltage on the board is, there's 3 transformers, one 220-110, 128-220 and a third one with no markings....wondering if it's the moment to improve the thing, i.e. what's the biggest wattage I can get in there, presuming the original would have been marginal in the first place due to cost?
So I'll need to order them in, that's fine, but, from that table, I'm struggling to figure out what I need wattagewise. Don't know what the voltage on the board is, there's 3 transformers, one 220-110, 128-220 and a third one with no markings....wondering if it's the moment to improve the thing, i.e. what's the biggest wattage I can get in there, presuming the original would have been marginal in the first place due to cost?
JMS1972
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Has the resistor actually blown? If so maybe get a higher wattage one in when you get replacements might be a bit marginal?
octo0072000
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can you not solder two of the new resistors together ?
don't know if it's gone or not, but the concensus of opinion is that if the transistors have gone, the resistor will have gone too, so for the cost / time will just change the lot, like I said might be worth upgrading to better quality / better rated kit at the same time, but being honest, I haven't got a clue what I'm doing here 
, not that's ever stopped me cracking on with it before ....
on further investigation, seems the physical dimension don't actually mean a lot, the sizes and ratings apprear to be pretty much meaningless in terms of capacity.. I would have expected some form of standard, but doesn't seem to be the case. Have found 1W's that's the same size as the original, but also found others that are 0.5W in the same dimensions.
, not that's ever stopped me cracking on with it before ....on further investigation, seems the physical dimension don't actually mean a lot, the sizes and ratings apprear to be pretty much meaningless in terms of capacity.. I would have expected some form of standard, but doesn't seem to be the case. Have found 1W's that's the same size as the original, but also found others that are 0.5W in the same dimensions.
Seadog
Save the planet. It's the only one with rum!
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You can, but you won't have the same resistance. You'd need two pairs of two in parallel soldered in series.
Check its resistance, it doesn't look burned out. Normally, it would either burn black if massive overload or discolour badly if ran too hot for a long time, that resistor looks pristine. Test with your meter, it should be 47k, if you don't get 47k, reverse the test probes and try again, you may get a different value.
You could always fabricate one from four of your 1/4 watt resistors - 2 in parallel series - but it will take up a lot of space
---R--- ----R ---
--- --- -----
---R--- ----R ---
If my ASCII Art works in this editor
Beaten by @Seadog and @octo0072000.
D
You could always fabricate one from four of your 1/4 watt resistors - 2 in parallel series - but it will take up a lot of space
---R--- ----R ---
--- --- -----
---R--- ----R ---
If my ASCII Art works in this editor
Beaten by @Seadog and @octo0072000.
D
@DSR agreed doesn't seem burned at all, just going by what others have said that it was most likely gone too. In any case I have to take it off, so can try first, if it's no good will replace it. aye for the cost of them, it's not worth making them up, they're only pennies if I figure out what size (W) I need.....
That resistor is 1/2 watt and 99.9% will be fine. They scorch when they fail in almost all cases.
your replacements are 1/4 watt but could be used if you have 4 of them. Wouldn’t be neat though but would prove things. 2 lots of 2 in series, then parallel the series pairs. Same value, double the power handling.
From my days as a service engineer back in the 80’s (when we used to fix things in the field) the first port of call was always the power devices like the FETs. Then capacitors starting with electrolytic ones which tend to burst if failed, then diodes and then resistors. Both diodes and resistors tend to go black when they fail.
3.15a is quite a common fuse value for PSU units and the ones with a T are a bit more robust being a slow blow. Quick enough to protect all but the most sensitive FETs but slow enough to not pop their filament at every little spike.
If you’ve a mind to, a cheap oscilloscope kit for a smartphone will give you a bit more insight into what’s happening at various points in the circuit. Adds to what you can glean from a meter.
And the obligatory story. Customer logs a call, nasty smell coming from their cash register. Me thinking it would be an ozone kind of smell from burning components told them to turn it off and wait for me. When I got there and opened it up there were no burnt components but there was a dead rat fried across the power board. Yeuk!
your replacements are 1/4 watt but could be used if you have 4 of them. Wouldn’t be neat though but would prove things. 2 lots of 2 in series, then parallel the series pairs. Same value, double the power handling.
From my days as a service engineer back in the 80’s (when we used to fix things in the field) the first port of call was always the power devices like the FETs. Then capacitors starting with electrolytic ones which tend to burst if failed, then diodes and then resistors. Both diodes and resistors tend to go black when they fail.
3.15a is quite a common fuse value for PSU units and the ones with a T are a bit more robust being a slow blow. Quick enough to protect all but the most sensitive FETs but slow enough to not pop their filament at every little spike.
If you’ve a mind to, a cheap oscilloscope kit for a smartphone will give you a bit more insight into what’s happening at various points in the circuit. Adds to what you can glean from a meter.
And the obligatory story. Customer logs a call, nasty smell coming from their cash register. Me thinking it would be an ozone kind of smell from burning components told them to turn it off and wait for me. When I got there and opened it up there were no burnt components but there was a dead rat fried across the power board. Yeuk!
well, all done, transistors replaced, (noted no thermal paste on them originally so made sure to add), both 47k resistors checked ok, fuse replaced, found a couple of dodgy soldered joints, so tickled them up a bit too... all powered up, ok power on, same as before all lit up. Started the ultrasonic, it had no water in it obviously, so just wanted a quick test, see if it worked then would try with water in... nah, didn't even get to that point, quick flash, and fuse popped again....
back to square one... Friday night, so beer time, but will have another look tomorrow evening...
thanks for all your help to date, we'll get there yet......we're no done with this thing...
back to square one... Friday night, so beer time, but will have another look tomorrow evening...
thanks for all your help to date, we'll get there yet......we're no done with this thing...
