I wasn't very clear on that... forgotten the bridge etc was on another board.
You connect the approx 400 volts DC from C801 and C805 to the input of the SMPS watching polarity of course.
Remember that the so called "negative" or PSU "zero" is in reality always at half mains potential. Everything on the primary side of T603 is the same. So be careful not to touch the PSU and anything else in the room... it's live.
Use the bulb of course on the input side and what we are going to measure (carefully) is the voltage across D601... or across C613 it's all the same at this point. The manual shows around 250 vdc so that seems a reasonable ball park figure bearing in mind the regulator is operating in linear mode.
Edit... your reading on the transistor is OK so all we can do is try it. Even if it were faulty it shouldn't damage anything testing this way.
You connect the approx 400 volts DC from C801 and C805 to the input of the SMPS watching polarity of course.
Remember that the so called "negative" or PSU "zero" is in reality always at half mains potential. Everything on the primary side of T603 is the same. So be careful not to touch the PSU and anything else in the room... it's live.
Use the bulb of course on the input side and what we are going to measure (carefully) is the voltage across D601... or across C613 it's all the same at this point. The manual shows around 250 vdc so that seems a reasonable ball park figure bearing in mind the regulator is operating in linear mode.
Edit... your reading on the transistor is OK so all we can do is try it. Even if it were faulty it shouldn't damage anything testing this way.
Last edited:
OK Mooly, check! Just to confirm (and sorry for all the newbie type questions), but thats positive multimeter lead to the anode, and negative to the diodes cathode right?
Yes, but it wouldn't matter measuring voltage. The meter would just show a - reading.
So it's bulb in series with the mains. The 400 volts from C801/805 taken from the caps to the smps. Just as shown on the circuit.
So it's bulb in series with the mains. The 400 volts from C801/805 taken from the caps to the smps. Just as shown on the circuit.
Gotcha
Just about to have some dinner but will do that later this evening - fingers crossed nothing on that SMPS will have any hissy-fits when I apply voltage...
Same here lol... feeding time.
Just make double sure the polarity is correct of the DC coming in.
Other than that, at this stage there isn't (famous last words) anything that could draw current barring an accidental short etc so it should be happy to just sit there powered up.
Just make double sure the polarity is correct of the DC coming in.
Other than that, at this stage there isn't (famous last words) anything that could draw current barring an accidental short etc so it should be happy to just sit there powered up.
Typically, just about to power-up, then notice a discrepancy between the DC input to the SMPS board & L601, and how it's actually soldered up in reality...
This is how it is in the manual (pages 26/27):
...and how it is on the board itself:
Also to be noted incase it helps anyone else who happens to be working on one of these inthe future, the wires going into the SMPS are grey and black, NOT violet & black, as it says...
This is how it is in the manual (pages 26/27):
An externally hosted image should be here but it was not working when we last tested it.
...and how it is on the board itself:
An externally hosted image should be here but it was not working when we last tested it.
Also to be noted incase it helps anyone else who happens to be working on one of these inthe future, the wires going into the SMPS are grey and black, NOT violet & black, as it says...
Last edited:
Odd that... the second one just shorts the supply.
Just fire it up John... as long as the positive end of C801 goes to Q601/613 and the negative end of C805 connects to the "PSU zero" which is the anode (lower end) of D601 it will be fine.
Just fire it up John... as long as the positive end of C801 goes to Q601/613 and the negative end of C805 connects to the "PSU zero" which is the anode (lower end) of D601 it will be fine.
On the second picture L601 should maybe be rotated 90 degrees... that would work on the diagram.
Yours must be correct because it worked before.
Yours must be correct because it worked before.
This is how it is in actuality:
The red dots are where L601s legs are, and the two yellow are blank solder points, points that L601 should be attached to according to the manual scan in post 247. The two legs visible between the pairs of red dots are just positioning legs for L601 I believe.
Odds bodkins!
An externally hosted image should be here but it was not working when we last tested it.
The red dots are where L601s legs are, and the two yellow are blank solder points, points that L601 should be attached to according to the manual scan in post 247. The two legs visible between the pairs of red dots are just positioning legs for L601 I believe.
Odds bodkins!
I think you'll find two different versions of coil could be fitted and the board is marked for just one. It can not be wrong as it would never have worked 🙂
If you want you can read the coil on low ohms range. It should read "short" between the top two red dots and the same between the bottom two. The opposite of how the PCB is marked.
If you want you can read the coil on low ohms range. It should read "short" between the top two red dots and the same between the bottom two. The opposite of how the PCB is marked.
Nope - between the top two red dots I get a continuity beep, and ditto for the two red dots below.
???
???
Yep it's confirmed - drew a diagram before I disconnected the wires fortunately. I wouldn't rely on my memory 😉
John... I'm going to have to go in a minute.
The wiring has to be correct, and you drew the wires too. Are you switching on tonight or do you want to leave it untill tomorrow ?
The wiring has to be correct, and you drew the wires too. Are you switching on tonight or do you want to leave it untill tomorrow ?
The white markings on the PCB are 90 degrees "wrong" for the coil you have fitted... put it down to a production change.
Yeah it doesn't look like it's been desoldered either - and it did work before as you said...
I'm going to turn it on in a moment - look towards Basingstoke you might see a flash 😉 (just kidding - I hope!).
Will chat to you tomorrow then Mooly. Thanks for your help today, and enjoy your evening Sir! 🙂
I'm going to turn it on in a moment - look towards Basingstoke you might see a flash 😉 (just kidding - I hope!).
Will chat to you tomorrow then Mooly. Thanks for your help today, and enjoy your evening Sir! 🙂