HP 8903 Faulty, A2 card and no -15v rail, Error 18 or 19 Diagnostic indicators

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HP 8903A Audio Analyzer 20Hz-100KHz
Error 18 - "Source cannot tune as requested."
Error 19 - 'Cannot confirm source frequency'.
NOTE
Although error codes 17,18 and 19 are listed as operating
Errors, they should be considered rather as Diagnostic indicators.
Special functions
40.0 Controller Reset
41.0 Controller Clear
42.0 Display Software Date
Faulty components
A2 card - C20 and C21 are 315uF - 16v (actual parts say 350uF)
A2 card - Fuse F2 blown
A13 main board - C1 and C2 missing
P10 Card - U2 -15v regulator
Please Note:
The main board has mains voltage potential,
High risk of electric shock.
DO AT YOUR OWN RISK

[@SoddingaboutSi]

Looks like its working wee. Once fixed mine is faultless 9 years later.