Hi,

you can use a regulated DC power supply and connect it to the big caps. Then you can test every power path of the psu and locate the short cut.

Martin

Hi = I cam't get a look at the Service Manual for the 6000 'cause the PDF is faulted - but have you checked the power transformer also the bridge rectifiers? (I'm assuming the 6000 is similar to the 5000 PSU-wise) = Brian (Northumberland)

hi ablaumeise!

a look into the service manual shows, that the 160 mA fuse handels the lower voltage section, which provides voltages for ic´s etc. so it could be leaking caps C1 3300μF(or slightly higher, if you can´t get hold of this value) or C10 2200μF. another posibility is broken ics in voltage regulation IC1 BDX34A or TR1 BC547B or IC2 MC 7815 CT (=15 volt regulator); also check diodes...

good luck + nice holidays!

jens

Yes, seeing C1 on module 16 shorted is quite common.

Martin

Many thanks for all the answers.

To answer the questions that occurred: Yes, the transformer and the rectifiers are working.

I desoldered C1 and C10 to have a closer look at them...as far as I can tell they are ok. They are not obviously leaking or something like that.

I will have a closer look at the other components Jens mentioned in the next days.

If I find no other failed components I will replace those two caps to see if that changes anything.

Put an ohmmeter across C1. You can't tell if a capacitor is good merely by looking at it.

Martin

When you unsoldered those caps did you try switching on to see if the fuse was still blowing? = Brian (Northumberland)

More tests = Can you read the cct diagram?  If so, try isolating the sections of PSU until the fuse stops blowing - this way you will narrow the fault down to one section.  For example: on module 16 dis pin 3 of IC2 also TR4 - if the fuse still blows, the fault is in that cct! Try this with other sections until you have isolated the faulty one.  Thanks for coming back - keep us all informed = Brian (Northumberland) 

Just to be sure that the fault is in the PSU (module 16), can you unplug it and run it unloaded and see if the fuse still blows? 

I think I would then do the isolating tests on the three (bridge rectifier load circuits) sections of the PSU. Hope this makes sense!

Dillen wrote:

Put an ohmmeter across C1. You can't tell if a capacitor is good merely by looking at it.

Martin

Sorry, I have no idea how to test if a capacitor is working or not...

Resistance is 0Ω....I guess that means it is broken?

blong wrote:

When you unsoldered those caps did you try switching on to see if the fuse was still blowing? = Brian (Northumberland)

Just tested that...and it works (well, or something like that)! With C1 unsoldered the fuse doesn't blow, some digits light up and the volume motor starts running.

I will see if I can get a replacement.