Schematic for Peavey Bandit 112

[johnheath]

many VOM have a diode checker function.... back in the day we had to use ohms scale  but ASSuming you have a vom with diode checker, you should measure a diode junction from both base to emitter and base to collector (+ lead on base for both measurements of NPN transistor). Collector emitter should measure open circuit.  Reverse polarity for checking PNP.  Note; do not measure diode junctions with power applied, and other connected local circuitry can affect these measurements.

JR

Thank you sir

I will save this answer for future troubleshooting

But... I fired it up and everything seems to be normal... both driver circuits show similar values (V) and R17 is not even warm so it could have been the C15 being shorted or faulty?

Both channels work nicely and respond "normally" to the guitar.

Just a question... would it be recommendable to change the other electrolyths in the power section? I mean if they are just old and recapping might be good?

Best regards

/John

 

[JohnRoberts]

Thank you sir

I will save this answer for future troubleshooting

But... I fired it up and everything seems to be normal... both driver circuits show similar values (V) and R17 is not even warm so it could have been the C15 being shorted or faulty?

Both channels work nicely and respond "normally" to the guitar.

Just a question... would it be recommendable to change the other electrolyths in the power section? I mean if they are just old and recapping might be good?

Best regards

/John

I would definitely replace all of that same value capacitance/voltage since they are likely from the same production lot so all suspect.

JR

 

[johnheath]

I would definitely replace all of that same value capacitance/voltage since they are likely from the same production lot so all suspect.

JR

Thank you sir

Yes, when I think about it it is not much labour so there are not many arguments  for not doing it

Thanks again

/John

 

[Whoops]

Hi, been reading this thread.

A transistor tester will be a great help for you, this one is the best for the money, it also tests most of other components, you will thank me in the future if you buy this:

Portable-MK328-LCR-ESR-Tester-transistor-inductance-capacitance-resistance-meter

http://www.ebay.co.uk/itm/Portable-MK328-LCR-ESR-Tester-transistor-inductance-capacitance-resistance-meter-/171927184554?epid=870231183&hash=item2807a8a4aa:g:MdoAAOSwk0pVgETb