Dewalt DCR020 Power Board – No Power, Need Help Identifying ICs / Possible Replacement

[snipersquad100]

Hi all,

I’m working on a Dewalt DCR020 jobsite radio that won’t power on.
So far, I’ve checked the following:

• The mains is reaching the transformer
• Transformer outputs ~15-20 V AC
• Bridge rectifier outputs ~15-20 V DC
• All fuses test OK
• The on/off button signal reaches the PCB connector

Despite this, the unit does not power up at all.

Inside, I’ve identified some of the ICs:

• ST7317 (appears to be an LCD driver, not the main MCU)
• LM2937L (voltage regulator)Not putting out power, 0.5V on the input
• Markings like FS1235, unknown IC
• Board number: BG0260756A-T53

The on/off signal goes to pins 1 &2 of the ribbon cable opposite the red wire. It goes into the CD4011, where it goes in and out of 3 and gates, then disappears under the DAB daughter board, where I can not pick it back up.
Can't find an MCU


At this point, I’m wondering:

1. Does anyone have a schematic for the DCR020?
2. Can anyone help identify the above ICs (especially FS1235)?
3. Has anyone repaired one of these and found the common failure points?

Photos attached of the power board for reference.

Any advice or experience with these Dewalt radios would be greatly appreciated!

Thanks,
Snipersquad100

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[madan1]

1. Can anyone help identify the above ICs (especially FS1235)? ------------------ The Kino 3 baseband processor is the latest generation of integrated system-on-chip,
   providing an optimised solution for WorldDMB Profile 1 DAB/DAB+/DMB-R and FM-RDS... https://www.electronicsdatasheets.co...d00.pdf?format

p.s. fun fact - According to this https://**************/dump/audio/ma.../73-1-0-100715 Makita dmr104 uses the same daughterboard/"brain".. unfortunately, still no schematics.
So I guess just start with the standard procedure - checking for shorts on caps and following the power rails.

I can't read the text on the eeprom, but according to the (censored) russian website above, it should be AT45DB041E. If so, when the unit is connected to power, there must be 1.65V - 3.6V on pins 6 and 7. I do not see any power converters on the daughter board (at least on top) so most likely all ICs on it use the same power rail.


And just found that http://www.df7sx.de/wp-content/uploads/2014/08/Verona_PB.pdf
board pinout - https://www.df7sx.de/wp-content/uploads/2014/08/radiowerkstatt_schema.pdf