MINILAB 603B

[TINY56]

HI i have a MINILAB BWD 603B  that is not working as it should

the function generator is not working - the unit powers up ok and output power supply 200v dc and 6.3v ac are ok  but no waveforms are generated

any help would be greatly appreciated in repairing this relic

[Shonky]

Got schematics?
http://bee.mif.pg.gda.pl/ciasteczkowypotwor/B.W.D/bwd_603b_mini-lab.pdf

[David Aurora]

I seem to recall these having a really good service manual, though I haven't looked at it for a million years (I've got one of these up on the shelves somewhere too).

First thing to check obviously is the supply rails for that section and then work from there, the service info is very readily available.

[TINY56]

THANKS for that info guys - i will need to do some more research as it appears there are a number revisions for the BWD 603B and mine is an early one   Issue 13   i think ??

[Shonky]

Issue 7 with schematics. Average of issue 23 and 7 is issue 15 so should be close yeah? 
https://archive.org/details/bwd-603-b-mini-lab/mode/2up

[TINY56]

thankyou for all the input much appreciated and it did help a bit - i think i have very early version  ser # 48800 series

i have 4 of these all with the same symptom - no wave form output so i assumed would all be the same fault -   not true

C1 10u 16v tantalum capacitor short circuit on 15v+ rail
AM on/off switch contacts dirty
main frequency adjust pot loose and rotated till it broke 2 of the three wire connected to it

all working now just have to calibrate

thanks again