grandmeister 36 produces no sound

Hallo, I'm new to the forum and have a problem. the amp worked well yesterday, but when I wanted to play today, it produced no sound at all.
When I press a guitarpick in the slot on the back with the amp on full power(36 watt), the leds blink 12 times, and the left one stays on. however if I run it on 16, 5,1 watt or redbox,
the leds blink 12 times, and the first three to the left of the amp stay on. what does this mean and what amI to do with it? Thanx for your reaction!

Firstly sorry for missing your post for so long. For some reason I'm not getting messages from the forum when a new post is made. I usually have that active so I can respond pretty quickly to each post which is reported. I'll look into it.

You may well have sorted this problem out by now but assuming you have not... First a little explanation. On full 36W all 4 of your output valves should be on. The single LED you are seeing is showing you that one of those is faulty in some way and the TSC system has detected it and turned it off for safety. When you set the power soak to anything other than 36W you turn off one pair of the output valves, the inners, to start by halving the power available. 18W mode (not 16W) is just that, full output but from only one pair of valves. The TSC is correctly telling you that too. You now have your single valve switched off and the inner pair are also switched off by the power soak setup.

I would start by removing the outer pair of EL84s which includes the dodgy one. This is only for testing purposes to see if you get output back with the TSC reported faulty valve removed though that might be an unconnected issue. Remove the pair which includes that valve, the outers. Assuming you get output back under those conditions, put the valves back according to the next step.

You now want to test that this is actually the valve and not the socket/support circuitry so swap the outer pair of valves when you replace them. You know the problem was in the left hand slot matching the LED so only the outer pair involving that slot should be swapped. Leave the two inner valves alone as they are showing good. Doing this means that when you test it again with your pick in the slot you should see the lit LED move to the other side following the suspected faulty valve from one side to the other. If the LED stays lit on the same side even when you have moved the valves, you have a problem in the circuitry controlling that valve socket and not in the valve itself. That will need a tech to fix!

My guess is that you will find the LED will shift sides too showing that you have to swap out at least the outer pair of valves for a matched pair. There is no real reason to have to buy all four. In the GM36 the valves work in set pairs, the inner pair together and the outer pair together. As long as each pair is matched across its own two valves, the matching of the valves between the two pairs is not really too important. By that I mean that, if your valves are labelled 1 2 3 4 as they stand, 1&4 must be matched, 2&3 must be matched, but it isn't too important to have both pairs 12 & 34 matched against each other. Buying a new matched quad is not a bad idea if you really want to and can afford it but make sure you keep only the known good pair, (the current inners), as they will be a good spare set for future problems. Put them in the new valve boxes and LABEL THEM CLEARLY so you can identify them when you need them. (Ask me why I recommend that! )

Can you update us with how things stand now? Then maybe try the simple tests and get back to us with the results.

first of all I want to thank you for your reaction!
this is the situation now: on36 watt when I put in a pick, all leds blink 11 times,
then one time 1,2 and 4, then one time 1 and 4, and then the 4leds stay on.
same situation on 18 , 5, 1 watt or red box out.
meanwhile I followed the thread on switching valves and ordered 2 JJ 5751, a JJ ECC83S
and 4 quad matched JJ EL 84's. I also ordered 2 slowblow 400 mamp fuses and 2 800 mamp fuses.
I have a friend who's very technical, and it shouldn't be a problem replacing everything after sorting out the problem. I'll keep you posted!.

Good news that you weren't locked out of using your amp.  I think from what you have said there that your problem is unlikely to reoccur in the short term.  You may have an iffy valve in there bringing the rest down with it but it seems unlikely to become constant.  The LEDs are showing you that your pairs are pretty well matched and in good condition.  You have pair 1 / 4 both bang on 13 blinks which is great, and 2 / 3 are on 12 / 11 blinks respectively which is also very good.  A difference of 1 blink is no problem at all as the TSC adjusts to compensate for such a small difference and matches them up automatically.  I don't think there is a real burning necessity to change out those valves but, as you have ordered them, it will stand you in good stead in the future.  Remember what I said about boxing the old ones up and labelling them clearly.  And make sure to add the date you swapped them out to the boxes too to keep a handle on when you genuinely last replaced the valve set.  You'll regret it if you don't. Glad you went for the 5751s and not something esoteric like a 12AT7 or even something unknown from the Russian military, (yes it really happens).  As you may have read me groaning about in the valve thread, they are definitely and inarguably not "substitutes" or "equivalents" or "family members".  They are all totally separate valve types with no common characteristics at all.  A Honda gearbox botched to a Ford engine taped in a Volvo chassis does not make for a good car.

It sounds like I was wrong about the TSC when you are not on 36W, my memory of this is a bit hazy as I don't use my GM36 much these days.  From what you say it seems it reports all 4 valves all of the time no matter what the power soak is set on, (which makes sense).  My apologies for misleading you like that.  That would mean that the original problem is now understandable.  With 3 out of 4 valves shut off by something, (perhaps the TSC for some reason), the amp could not give you anything like its normal action so it shut off all sound.  Though it seems to be working now there is something I would do when you get a minute before you rely on it.

If you have any special voices programmed in, back these up or at least take written copies of the full range of their settings.  If you haven't got that far yet that's no problem.  Then do a factory reset of the software.  This needs no equipment or special downloads.  It will purge the amp's software setup and reset everything back to original factory spec.  That's not just the voices, the firmware in the amp's digital systems is cleansed too.  Sometimes, (not often but we have seen it here a few times), you can get corruption in the driving software which causes odd effects when that area of the programme is accessed by the amp.  It would be good to know that your software is pristine without any of those bugs hidden away and waiting to pounce.

The procedure for a factory reset is in the manual in section 8.3.  It's easy, just press "Store" and "FX Access" together while powering the amp up with the Power/On switch. Both buttons will flash three times to indicate a successful factory reset.  I do stress, copy any personal voice settings first as these are permanently wiped along with the firmware.

Do keep in touch with us and let us know how your new valves get on.  If you have the original Chinese valves in there you may notice some difference but I really wouldn't expect miracles in tone.  This is subjective however and some people rave over the minutest differences they can detect, (or at least they think they can ).  For my money there are other factors which change with each playing venue which have a far greater effect on tone and wipe out any subtle changes a valve type may make.  I stress again.  There IS absolutely NO difference between valve makes caused by frequency response factors.  ALL 12AX7s which carry that model number MUST conform to a flat frequency response into the MHz region.  Any genuine differences come down to different overload characteristics which is driving the valve beyond its design capabilities and out of the area which the valve's designers try to control.  The people who blather on about one make's top end or another make's solidity of bass are talking out of their asses!  When they make their test comparisons they always have the amp set so it is heavily into their favourite distortion region and that is what causes some to sound sharper or smoother.  Turn the amp way down into the ultra clean linear region and take an honest listen then.  Of course engineers can show this easily with more sensitive equipment than anyone's ears, but hey, don't let the proven truth get in the way of a good story.  Or a good income?