Hey all this is a great and valuable site with really kool ppl, who are helpful and kind. I have been reading this site for a long time and never posted until now. Well anyways have a marshall head 2210 and want to diy repair and troubleshooting, seen a lot of books, but would like to find a step by step instructions or a trouble shooting guide and or chart. Have webers dvds and darts ebook, and some others but most of the info I have seen bounces around and is not a straight thru type of trouble shooting guide. If you have links plx post or direct to the right posting. I searched you tube and not a complete guide if, one is available. Thanks in advance , admin keep up the great work!
C ya all
C ya all
Have you been on the Marshall forum?Marshall Amp Forum - MarshallForum.com/workbench/33284-jcm-800-2210-problems.html
there is no "one" guide to troubleshooting or "blanket" approach to troubleshooting.
what is wrong with your Marshall 2210?
what is wrong with your Marshall 2210?
I have not seen a diagnostic tree approach to repairing valve amplifiers. Anyone with general understanding of how they work can just take the symptoms into account and that would lead them to start looking around a particular area. An example would be the amp is "motorboating", this would lead a tech probably to look at the power supply decoupling capacitors first.
What's wrong with the amp?
What's wrong with the amp?
Since this is a guitar amplifier the best place for this thread is definitely in Instruments & Amplifiers so I will move it over there now..😀
well tubes light up, no sound at all,. great advice but there must be an systematic approach to repair,. seen some trouble shooting charts on other forums,, one I seen is too small to read,.. some of the books have them in there, but now funds are tight so to buy a book right now isn't going to work🙂
Well, so far at least you know Tubes are lighting up...Heaters/supply is working...we are still in the dark a lot though...you have no sound no output....so either clean signal is getting lost somewhere which can be very common with something bad/going on obviously...assuming everything with tubes/ voltages/output transformer and cab/speakers connections is okay....
with any amp with age first thing I want to look at and suspect is tubes and capacitors./solder points/joints/connections...So yes there is a Systematic approach to troubleshooting/diagnostics...you know so far mains are coming in fine Power Xfmer heater supply is working at least...assuming its stepping up your main HV B+ as well...go from there pretty much.
with any amp with age first thing I want to look at and suspect is tubes and capacitors./solder points/joints/connections...So yes there is a Systematic approach to troubleshooting/diagnostics...you know so far mains are coming in fine Power Xfmer heater supply is working at least...assuming its stepping up your main HV B+ as well...go from there pretty much.
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That I hope is fine being heater supply is working getting there...if all that power supply related is okay....I mean yeah I want to start really looking at connections/Caps etc thinking about clean signal getting lost somewhere in the front end being I don't know how many times seen it with multiple amps lol
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chizm
so your trusty multimeter confirmed that all the fuses are good.
can you confirm that the speaker and associated cabling is ok.(also confirm that the jack cord your using is good) and while you've got your meter out why not check the b+ plate voltage.
then you can signal trace with your trusty o'scope...
if you don't have test gear all the charts in the world aren't gonna help.
if your looking for guidance many here can and will help you.
you don't have to buy a book local public libraries can bring in title's like:"Electric Guitar Amplifier Handbook" by Jack Darr it's dated but still a highly useful primer for anyone looking to learn how to service guitar amps.
so your trusty multimeter confirmed that all the fuses are good.
can you confirm that the speaker and associated cabling is ok.(also confirm that the jack cord your using is good) and while you've got your meter out why not check the b+ plate voltage.
then you can signal trace with your trusty o'scope...
if you don't have test gear all the charts in the world aren't gonna help.
if your looking for guidance many here can and will help you.
you don't have to buy a book local public libraries can bring in title's like:"Electric Guitar Amplifier Handbook" by Jack Darr it's dated but still a highly useful primer for anyone looking to learn how to service guitar amps.
One of the first items that should be included in a "repair guide for tube amps" is finding a schematic.
Then study the schematic and try to recreate the amp and it's signal path in your head.
Maybe draw a block schematic; it makes repair a lot easier and more structural.
My teacher, allmost half a century ago said:
"Have a good look at the amp, components, wiring and connections!
Take your time for it.
In most cases the amp is half way it's repair..."
Wise words... And I stil do when I receive an unknown amp.
As mentioned by others;
Check the voltages and write them down.
Do not rely on your memory...
Write them down, tube by tube, pin by pin.
Then if you can not go further, let us know.
Keep a record of all the moves you've done and change one part at the time.
Then study the schematic and try to recreate the amp and it's signal path in your head.
Maybe draw a block schematic; it makes repair a lot easier and more structural.
My teacher, allmost half a century ago said:
"Have a good look at the amp, components, wiring and connections!
Take your time for it.
In most cases the amp is half way it's repair..."
Wise words... And I stil do when I receive an unknown amp.
As mentioned by others;
Check the voltages and write them down.
Do not rely on your memory...
Write them down, tube by tube, pin by pin.
Then if you can not go further, let us know.
Keep a record of all the moves you've done and change one part at the time.
Have you got a schematic? Here is a link to yours, top of the page.
Marshall Schematics
I like the link Enzo gave also. Click on debug, then Order of Suspicion. Components are #4 on the list. Tubes and Power supply are first and second after operator error. Just because tubes are lit doesn't mean they are working properly. Replace tubes, one at a time, with known good ones first, then check B+ and other power supply voltages.
Marshall Schematics
I like the link Enzo gave also. Click on debug, then Order of Suspicion. Components are #4 on the list. Tubes and Power supply are first and second after operator error. Just because tubes are lit doesn't mean they are working properly. Replace tubes, one at a time, with known good ones first, then check B+ and other power supply voltages.
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Check voltages first
and then think about
swapping tubes.
NO HT (High Tension)
Check the AC voltage before the standby switch.
Then after the switch.
Then check the DC voltage after the Diodes (D9-D12) at the positive of C49.
HT OK?
Check the DC voltage after the choke T3.
HT OK?
Check the DC voltage after 59?
HT OK?
Is there HV on the valves V5, V6-9?
Let us know... (With the measured values)
and then think about
swapping tubes.
NO HT (High Tension)
Check the AC voltage before the standby switch.
Then after the switch.
Then check the DC voltage after the Diodes (D9-D12) at the positive of C49.
HT OK?
Check the DC voltage after the choke T3.
HT OK?
Check the DC voltage after 59?
HT OK?
Is there HV on the valves V5, V6-9?
Let us know... (With the measured values)
When you say no sound at all, you are saying that even with your ears directly up to the speaker you don't hear the slightest hiss or hum? If this is the case then as others have suggested check the high voltage power supply.
^^^^^^^^^^ Follow this.
^^^^^^^^^^ Follow this.
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