mmm, ...are you sure that the pedal has never been feeded with inverse polarity?
i could easily be wrong (and i hope so), but probably one or more than one component is broken (ICs, transistors). this can easily happen if you use a wrong polarity adaptor (or an alternate current power supply instead of continous current)
anyway i would try and substitute r52 (with a normal through-hole 1/4W res it's ok, don't do it if you're not skilled with soldering), see if it still gets hot, and if not check voltages on the PCB
EDIT: i have seen now your edited message.
so if you can measure voltages without smoke, then get voltages on the OP-Amps (2 smaller ICs with 8 pins), expecially PIN8; here you should have around 9V
EDIT2: sorry, it's late in the night and i'm tired. yes, voltages on c28 and c29 are too low. on c28 you should measure 9V
Tech21 - Sansamp GT2 [traced]
Thank you for your reply!
Ground and +9V still in short circuit (35 Ohm resistance between them). And I cant understand why. Maybe I should check out the rest of the ICs...
No i dont. I've desoldering and checked all electrolitic caps - they are all working ok. TL072 is ok too.Intripped wrote:mmm, ...are you sure that the pedal has never been feeded with inverse polarity?
R52 is good.Intripped wrote:anyway i would try and substitute r52 (with a normal through-hole 1/4W res it's ok, don't do it if you're not skilled with soldering), see if it still gets hot, and if not check voltages on the PCB
Ground and +9V still in short circuit (35 Ohm resistance between them). And I cant understand why. Maybe I should check out the rest of the ICs...
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Intripped
- Cap Cooler
For many reasons it's not easy to help you out with this issue: schematic is not 100% complete, the PCB has smd components (very difficult to work with), ...I'm not a real experienced tech.
Anyway, what I would do is to desolder the ICs, one by one, and check if the correct supply voltage comes back after each desoldering.
I would do the same with transistors.
and also diodes, if they are implemented for inverse polarity protection, but I can't say it looking at the schematic.
If you have a friend with electronic skills I think you had better ask him for some help
Anyway, what I would do is to desolder the ICs, one by one, and check if the correct supply voltage comes back after each desoldering.
I would do the same with transistors.
and also diodes, if they are implemented for inverse polarity protection, but I can't say it looking at the schematic.
If you have a friend with electronic skills I think you had better ask him for some help