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.
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...
That was a fun one Dave! lol
Nice Futaba display though.
Nice Futaba display though.
Was interesting how it was basically backwards, so you don't see the grid and cathode wires.
Nice that you posted the "How VFD displays work" before!
Thanks
The inductor (L1 min 25:40) seems sealed with silicon to avoid buzzing. I have never seen any as nice as that.
Does any one know who could produce them?
Great job Dave! Murphy is indeed a tricky bastard lol. Re-checking your steps is yet another stuff that I learnt by watching your repair videos. And kudos to Sony for making such detailed service manuals, they are amazing.
It's easy to get misled during a "debugging" session, being hardware or software. And often we tend to focus on things that we think must be the most reasonable culprit, and spend a bit too much time on these.
The key is the following:
- Be systematic. Test every little thing that is a possible cause of failure, however silly it seems, one by one. As long as it's factually a possible cause.
- Don't run in circles.
I guess Murphy showing up this time was payback for all those repair videos that turned out to be easy fixes.
FPC cable! It's gotta be the FPC cable! Come on, check the FPC cable! I've never felt so frustrated by waiting for a you, Dave, to figure it out in my life.
On the plus side, I guessed correctly.
Thanks for the repair vid!
FPC cable! It's gotta be the FPC cable! Come on, check the FPC cable! I've never felt so frustrated by waiting for a you, Dave, to figure it out in my life.
Did it feel like watching "who wants to be a millionaire" and knowing the answer to the last question?