I just finished my second AMP4 and I am quite disapointed :
- the overload LED (J3 pin 1) is permanently on, although nothing is connected to the inputs. Same if I ground them.
- the relay is not clicking when shorting J5 & J6.
- consequently I cannot set the offset.
- I checked the voltages : Q10 reads 9,04 volts, and Q2 reads 5,07 volts, everything seems okay and keeps nicely warm.
- you can look at chip solderings here to tell me if anything is wrong : http://www.dcx2496.fr/photos/2nd_AMP4.jpg
you may want to compare with this one taken on the working AMP4 http://www.dcx2496.fr/photos/tk2050.jpg
Can't see any difference, apart from the fact I got a bit more skilled now
Any idea of what I should look for ?
Thanks for your help and Merry Christmas !
Edited 3 hours after posting : for some reason, after measuring various voltages around Q2 the overload LED went off. Strangely enough
the temperature has raised drastically on both regulators Q10 & Q2 since, although voltages are within specs. The TC2000 chip gets pretty hot too, is that normal [?]
The TP2050 gets mildly warm.
I am really baffled by this now [xx(]