Forget the fancy silver or lead-free solder.
Get some good old 60/40 tin/lead solder !
It would not surprise me if you had a load of dry joints.
You'll need a solder sucker or solder wick to get rid of the old solder joints.
And if you've had problems getting (or trying to get) a decent joint, it also would not surprise me if you had several cracked or broken tracks and/or lifted pads.
Andy
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Have you measured voltage on any of the rails?
forget the mains side. Do you have any voltage on the secondary rails? for example how many volts DC do you see if you put 1 probe on each of the fuses?
You need to establish where the voltage is getting to.
Have you downloaded the service manual yet?
Also a Andy says old school solder does the best job! All my Silver solder goes dull compared to old stuff.
Can you take a photo. I still think you could be barking up the wrong tree with those mains connections.
forget the mains side. Do you have any voltage on the secondary rails? for example how many volts DC do you see if you put 1 probe on each of the fuses?
You need to establish where the voltage is getting to.
Have you downloaded the service manual yet?
Also a Andy says old school solder does the best job! All my Silver solder goes dull compared to old stuff.
Can you take a photo. I still think you could be barking up the wrong tree with those mains connections.
Excellent. It is a very important mod, if you can supply those rails with a 50VA tx instead of the original do so.
Brent
Silver solder is dull, especially so if your soldering iron is too hot or the solder has been hot for too long.
Brent
Brent
Did you do the opamp supply psu as well or just the pair on the servo?
Must be time for some pics??
tested switch with digital multimeter 200 ohms - reading from 1 to 0.04 - should be ok?
Power definately getting to tx.
With DMM set to 200m DCV FH12 gives 01.1 / FH11 gives the same they both fluctuate up and down a little?
How do I continue testing from there and what settings should I have the DMM on?
Thanks in advance guys,
Adam 🙂
Power definately getting to tx.
With DMM set to 200m DCV FH12 gives 01.1 / FH11 gives the same they both fluctuate up and down a little?
How do I continue testing from there and what settings should I have the DMM on?
Thanks in advance guys,
Adam 🙂
Hi Adam
Have you measured the voltage on the fuses? You should be getting about 20v AC. Rather than explain how to find a gnd, just put one probe on each fuse at the same time. If you read somewhere round about 20v its fine.
Have you tried to look at the PSU section of the service manual yet?
Have you measured the voltage on the fuses? You should be getting about 20v AC. Rather than explain how to find a gnd, just put one probe on each fuse at the same time. If you read somewhere round about 20v its fine.
Have you tried to look at the PSU section of the service manual yet?
Thanks for the speedy reply!!! It measured 20.3v
Had a look at the service manual bit not really got a clue what to look for!
Adam 🙂
right thats good!!!
It means you can forget the mains side because its all fine. now you need to measure some DC voltages.
You need to locate a GND point. You can use the heatsink of the 5v regulator as the gnd.
The 5v regulator is the 3 pin device attached to the heatsink in the middle of the board.
Black wire from the meter to gnd and red wire to the jumper U163 just near to the device. Have you got 5v?
It means you can forget the mains side because its all fine. now you need to measure some DC voltages.
You need to locate a GND point. You can use the heatsink of the 5v regulator as the gnd.
The 5v regulator is the 3 pin device attached to the heatsink in the middle of the board.
Black wire from the meter to gnd and red wire to the jumper U163 just near to the device. Have you got 5v?
OK, here goes: touched black onto heatsink and red onto shiny wire strip labeled U163 get 00.1 on setting ACV 200 on DMM.
Thanks again,
Adam
Thanks again,
Adam
the left pin is the supply pin so check from GND to supply.
check for a supply voltage of about 11v
Using the picture, you should have about 11v from IN to COM (supply to Gnd)
If you have a supply but no 5v on the OUT pin, your 5v regulator is dead. If you have no supply voltage, it must be either diodes, fuse or mechanical failure (track or solder joint)
check for a supply voltage of about 11v
Using the picture, you should have about 11v from IN to COM (supply to Gnd)
If you have a supply but no 5v on the OUT pin, your 5v regulator is dead. If you have no supply voltage, it must be either diodes, fuse or mechanical failure (track or solder joint)
An externally hosted image should be here but it was not working when we last tested it.
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Tried that and it sparked and both the glass fuses lit up like xmas trees. Seems to be dead now. Think the fuse in plug has gone...
Adam 🙂
Adam 🙂
Measuring the voltage on a 3-pin reg is a very easy way to short things out. There are some wire links (U200 springs to mind, could be wrong though) that are much more convenient for finding +10VDC in the CD63.
Blown fuses aren't the end of the world. You'll obviously want to replace those to resume testing.
Blown fuses aren't the end of the world. You'll obviously want to replace those to resume testing.
oops! sounds like you managed to short the supply to gnd! Get yourself some replacement fuses 630mA Anti Serge (slow blow) glass and try again. The fact that it did that means you have the volts on the input pin.
Double check the output pin for 5v once you've replaced the fuses. Maplin sell them if you have one nearby. I doubt the fuse in the mains plug will have gone though!
Double check the output pin for 5v once you've replaced the fuses. Maplin sell them if you have one nearby. I doubt the fuse in the mains plug will have gone though!