Oh joy :( Are they related to dingoes kidneys?
regulator in that circuit I wonder ?
miniature PCB size ones, so it must have been in the external psu. The interpretation of what -15v is probably a bit flexible so could be as high as
-15sqr(2). Can't find LM7809's, even on eBay, except from China so it's got to be an LM7812.
Might be a good idea to put something like 2000uF across the input then and replace or install the bypass small decoupling capacitors around the
7815 as was discussed elsewhere in this thread.You can buy any generic 7815 it doesn't have to be the old LM78xx part.
ISTR Rapid will even sell one off. Delivery will sting a bit tho.
Maplin will sell you one for about a quid collect in store.