Crate BT50

[Valvehead]

Crate BT-50 bass combo - have my friends amp here today , with no output to the speaker.
Speaker is ok, headphone jack works---Ext speaker jack works.

Nothing burnt or getting hot.

+23v / -23v to each output chip (U2-U3) . They are tda2050 .

ill attach the schematic -- possibly U2 or U3 is bad ? Do they work as a push/pull type circuit or are they separate? Im not good with solid state stuff !



file:///C:/Users/km/AppData/Local/Temp/wz389d/PWA%20Bass%20Amplifier%20PCB%20Schematics%20%28848SCH_A% 29.pdf

[The Dude]

It looks like the external speaker jack is a switching jack. If it works, your power amp is working. I would guess you have a bad switching jack or cold solder on the jack.

[g1]

That schematic didn't upload correctly.
If the ext. spkr jack works, then the amp section is ok.
There are cutout contacts in the headphone jack that are possibly not closing when you unplug the headphones, or the solder may be bad at the headphone jack.

[The Dude]

PWA Bass Amplifier PCB Schematics (848SCH_A).pdf

Edit: Sorry, apparently my link doesn't work either.

[DrGonz78]

Here is a bunch of goodies!!

[Valvehead]

All the jacks are making contact / closing---but, i havent pulled the pcb out to check solder joints yet

[Valvehead]

ahhh----some cracked joints.


thanks fellas--amp is fine now