Hi everyone,
Adrian and I are currently in the process of repairing the DECtalk DTC03. This table is my current reading of all of the capacitors on the power supply board.
The power supply board is labelled ASTEC AA12242 manufactured ~May 1984.
Capacitors:
| Pad name | Capacitor | Dimensions | Checked? |
|---|---|---|---|
| C1 | ?? V ; 1 uF | ||
| C2 | Unpopulated if for 240 V, otherwise 250 V ; 0.22 uF |
||
| C3 | 400 V ; 1000 pF | ||
| C4 | 400 V ; 1000 pF | ||
| C5 | 400 V; 0.1 uF | ||
| C6 | probably 250 V ; 100 uF | ||
| C8 | 250 V ; 100 uF | ||
| C9 | probably 250 V ; 100 uF | ||
| C10 | 10 V ; 470 uF | ||
| C12 | 250 V ; 100 uF | ||
| C13 | 100 V ; 220 nF | ||
| C15 | 10 V ; 1000 uF | 10 mm x 45 mm | |
| C16 | 10 V ; 1000 uF | 10 mm x 45 mm | |
| C17 | 10 V ; 1000 uF | 10 mm x 45 mm | |
| C18 | 10 V ; 1000 uF | 10 mm x 45 mm | |
| C20 | 10 V; 1000 uF | 10 mm x 45 mm | |
| C21 | 10 V; 1000 uF | 10 mm x 45 mm | |
| C22 | 25 V; 220 uF | ||
| C23 | Unpopulated | N/A | |
| C25 | 25 V; 100 uF | ||
| C26 | 16 V; 680 uF | 10 mm x 45 mm |  MY |
| C27 | 16 V; 680 uF | 10 mm x 45 mm | MY |
| C28 | 25 V; 1000 uF | ||
| C30 | 100 V ; 220 nF | ||
| C31 | ?? can’t read | ||
| C35 | 275 V(AC) ; 1 uF |
Annotations are not yet finished, still pending a final check through and labeling all dimensions. If an entry is missing, either I missed it, or it’s unpopulated. I labelled C23 as unpopulated because it may look like it should be on the board. Some values are illegible in the current setup and are read as ??.
We are currently in the works to replace the caps and hopefully the power supply will work again. Currently, it works, but the output voltage is wrong.
Cheers,
Mel