EEVblog

Repair of a Sony HCD-SBT20B Bluetooth Stereo. What it’s like to nail the repair and then, well come-a-gutsa and have to go down the rabbit hole to fix the fix all whilst battling bad design info.

How VFD displays work: https://www.youtube.com/watch?v=gZIRPJt69sM
Mud run video: https://www.youtube.com/watch?v=yAahT8_P-_E
Tektronix autopsy: https://www.youtube.com/watch?v=VZCokbsTwmQ
Forum: https://www.eevblog.com/forum/blog/eevblog-1603-sony-amplifier-repair/

00:00 – Sony HCD-SBT20B Bluetooth Stereo with a water ingress problem
01:17 – Water isn’t that bad actually, even mud.
02:49 – Comically long screwdriver time
04:09 – Vacuum Fluorescent display for all you VFD fanboys
05:10 – Annoying construction
06:14 – Logic level problem? Doesn’t seem to be the PSU.
07:57 – Yuck!
09:58 – PCB Cleaning time
12:11 – Did the cleaning work?
13:28 – Hang on, I think I see something…
14:36 – More corrosion
15:21 – Back to measuring voltages on the VFD
17:15 – Handy use of Auto Hold
18:00 – VFD dispaly under the microscope
19:33 – Cathode measurement
20:13 – Anode connection tracing
22:10 – I wouldn’t have designed it like this
23:08 – Sanity check
24:32 – What’s in the can?
28:16 – Schematic time. Sony service manuals are something else
33:22 – Don’t come-a-gutsa on dual diode pinouts
35:16 – Let’s power it up on the bench
37:19 – There’s something very strange about this…
40:04 – Oh FFS!
42:03 – Now it’ll work…