Panasonic SA-BT230 "Please Wait"

[midsomerjambo]

Hi,

I have a SA-BT230 home cinema system that is showing "Please Wait" all the time. On a different thread I was able to obtain a copy of the service manual and proceeded on the assumption that something was probably wrong with the power supply (SMPS).

I carried out the continuity checks on the main transformer (admittedly in situ) as indicated in the service manual. When I checked between pins 16 and 17 I got a short. According to the circuit diagram, pin 17 is +18V and pin 16 is ground. I'd have expected a short here to blow the fuse but it hasn't. Anyway, on checking the voltage across the speaker connectors I had about 0.5V on 1, 2, 3 and 4 and next to nothing on 5 and 6. Going by what was said on the earlier thread, that would indicate that the D-amp IC responsible for those speaker outputs is fried.

If this is the case, ideally I'd replace the D-amp and the SMPS boards (I don't see me replacing the IC), but I can't find a source for a SMPS board and the D-amp sources I found are all overseas. I could source a replacement transformer but I've no way of telling whether any of the other SMPS components are fried and I don't want to put a new D-amp in just to have it blown because the SMPS is still misbehaving.

Any suggestions (apart from buy a new system - which I'm starting to seriously consider)?

Regards, MSJ

[dick_barton]

Re: Panasonic SA-BT230 "Please Wait"

What voltage do you have when you measure between pin 16 & Pin 17.

[midsomerjambo]

Re: Panasonic SA-BT230 "Please Wait"

If it's reading short on a con check, I'd have thought 0V but I'll check and let you know. I intend to remove capacitor C5183 from the SMPS PCB and test it for a short in isolation although I'd be surprised as I'd expect a capacitor to fail open circuit. If that checks out, I'll remove the main transformer and test it in isolation.

Regards, MSJ

[dick_barton]

Re: Panasonic SA-BT230 "Please Wait"

If it's reading short on a con check, I'd have thought 0V but I'll check and let you know. I intend to remove capacitor C5183 from the SMPS PCB and test it for a short in isolation although I'd be surprised as I'd expect a capacitor to fail open circuit. If that checks out, I'll remove the main transformer and test it in isolation.

Regards, MSJ

Transformers having a low dc resistance reading is normal.

[dick_barton]

Re: Panasonic SA-BT230 "Please Wait"

Have you tried any of the other outputs ie. video out and connected that to your tv?

[davph]

Re: Panasonic SA-BT230 "Please Wait"

Hi

Try main smoother capacitor in power supply. Sorry cant remember circuit reference but have seen it o/c a few times.

[R_J]

Re: Panasonic SA-BT230 "Please Wait"

If you are getting "Please wait" I doubt the fault is with the power supply. most likely logic board
You could try a master reset:
While the unit is off, press and hold [+VOLUME], [OPEN/CLOSE] and [POWER] on the main unit at the same time for more than 5 seconds.

[davph]

Re: Panasonic SA-BT230 "Please Wait"

Yeah R_J you would think so but I've had the fault a few times. Will show "Please wait" or "F76" replacing C5712 has cured the fault.

[R_J]

Re: Panasonic SA-BT230 "Please Wait"

This is from the manual:
F76 error is "Abnormality in the output voltage of stabilized power supply" Description of error "in normal operation when DCDET1 is detected (low) for two consecutive times, F76 is displayed on FL for 1 second and after that PCONT will be turned to (low). This is due to any of the DC voltages (+9V, +7V, -7V, +5V, +5.3V etc.)

so bad C5712 (main filter) could cause the error.
Also mech & main board are replaced together ( I did a bunch of these when they were unde warranty)

[midsomerjambo]

Re: Panasonic SA-BT230 "Please Wait"

Many thanks chaps, I'll try replacing the cap as advised and let you know. However, I did check the output voltages to the Power PCB, Main PCB and D-Amp PCB and they all *seemed* to be OK.

Regards, MSJ

[joegalati]

Re: Panasonic SA-BT230 "Please Wait"

Hi midsomerjambo,
The symptoms you describe are exactly the same as I am having with my Panasonic BT337. They are almost identical models I believe.

Mine had been repeating the "Please Wait" message for the past couple of years, once or twice a year, but power cable out/in always seemed to fix it until today.

Just wondering if you had discovered anything since your last message.

Cheers,
joe

[midsomerjambo]

Re: Panasonic SA-BT230 "Please Wait"

I'm waiting for a replacement cap to be delivered but meantime maybe someone could suggest how to test the existing cap out of circuit. It doesn't look damaged and I'd have thought a duff electrolytic cap would show some physical sign of a problem. Also, the circuit diagram says the cap should be 270uF/400V but the actual cap on the board is 180uF/400V. Should I replace like for like or go with the circuit diagram/parts list? A word of warning - the underside of the PCB is marked "HOT" near the cap and they ain't joking - even disconnected for days it will bite if you touch anything bare in the vicinity (which sort of makes me wonder if there is actually anything wrong with C5712).

Cheers, Gerry

[joegalati]

Re: Panasonic SA-BT230 "Please Wait"

Update: I replaced C5712 on my BT337. The replaced cap was exact same specs as original capacitor.

No joy - issue "Please Wait" loop still persists.

Would appreciate any ideas that haven't already been mentioned above if someone comes across this thread.

Thanks in advance.