Jcm2000 Dsl 401 Not changing channels

[hutsch]

ok
looked here
and led 3 is the green led - clean channel
pin 9 & 10 conectec to chassi
i dont have the foot here to see if it works ,

[hutsch]

hello guys
And I did it, fynally it worked
started to heat up the solder, cleaned everynthing and replaced the C3 capacitor.
and it worked
thank guys for the help
i learned a lot with this
a last thing wat is correct bias regulation for this amp?

[g1]

There is a 3 pin test point for setting the bias. Factory setting is 1.375VDC from the center pin to either outside pin.

[DrGonz78]

Ah Ha! Just worked a bunch on this amp too. Tons of problems to fix and then I added similar problem w/ clean channel not working and led not lighting up. I replaced T1-T3 and it fixed the problem.

However, I kept wonder on the schematic what CON5 was for....? My guess is that is the 3 pin test point for setting bias.

[Yelly]

hello guys
And I did it, fynally it worked
started to heat up the solder, cleaned everynthing and replaced the C3 capacitor.
and it worked
thank guys for the help
i learned a lot with this
a last thing wat is correct bias regulation for this amp?

Correct?
Depends on what the tubes draw at the given platevoltage. I'll recommend learning how to bias in general, but I can say you probably want a platedissipation around 55%-70% of the tubes maxdissipation. Look up the datasheet for the tube (probably EL34 in dsl)

[Enzo]

It is a DSL401, which uses EL84. I thought the factory schematic had a bias test point recommendation.

[DrGonz78]

Yeah this is the bias page that I have w/ the schematic for the DSL 201/401 models.

[Guitarman53]

JCM2000 DSL combo manual channel switching issue of no clean (green) channel.

[QUOTE=hutsch;244777]hello guys
And I did it, finally it worked
started to heat up the solder, cleaned evernthing and replaced the C3 capacitor.
and it worked

How I fixed my MARSHALL JCM2000 DSL combo manual channel switching issue.
PROBLEM: Green LED and therefore "Clean Channel" not operating from front panel switches. (Although OK via foot-switch)
DIAGNOSES: All channels switched via foot-switch so I was doubtful that there was a component issue.
Due to this thread I zoned in on the foot-switch input jack. Thank you all.
SOLUTION: Looking at the foot-switch socket, there are 3 spring-metal "clamps" that open to allow contact with the foot-switch plug when it's inserted.
I found that the tip connector (the most innermost "clamp" ) was not springing back hard enough to create an electrical connection when the plug was removed.
So I inserted a plug all the way in, thus opening the tip "clamp" with the tip of the plug. I got a screwdriver and forced/bent the end of the metal clip downwards around the tip of the inserted plug.
Upon removal of the foot-switch plug, I immediately heard a "click" and the front green LED turned on. I then tested the 3 LEDs & channels with a guitar via manual and foot-switch operation.
Fixed!!! Hope this helps someone else.