Metropoulos Forum

Hi guys!
I'm posting here about a Marshall 2203 from 1985 that's not working anymore. The guys wants to sell it for around 600$ and here's the problem it has. I don't know if I should buy it for that price or if it's gonna be a buck sucker...

Here is what happened:
The guy powered it ON and left the standby OFF for about ten minutes. Then he turned it ON and had a faint sound coming out of it, then no sound.
The 1A fuse blew and 2 power tubes turned black, burnt obviously (the ones farther away from the preamp tubes). They weren't old at all.

You should know that the voltage here is around 230V and the amp is set at 240V (for what reason I don't know).

SO I need you guys to tell me what the problem could be and if it's a good deal or not! I've built five Metro JTM45s but I don't know if I can troubleshoot a 2203, particularly if it has a PCB (which I think was the case in 1985, right?)

Thanks a lot!

Hey,

The PCB Layout is well documented in the internet, so there is no problem finding the components or troubleshooting etc. Although you should be very careful when soldering or desoldering, the copper layer tends to peel off of the PCB. So keep the soldering time short and the temperature as low as possible.
About the actual problem. There are several possibilities what can be wrong, including the OT, what would be the biggest as you called it buck sucker.
I think with a little help from the board, you should be able to fix the problem.

Cheers Michael

My first suggestion would be to try new power tubes and check out those screen resistors. These later PCB amps (with the pots and jacks mounted on the PCB) are slightly more fragile on the PCB tracks when removing components than the amps that came before them, but it's less likely to be a board issue anyway. Board issue's are usually glaringly obvious, unless the bias caps or diode's have gone bad.

Anyway, I reiterate, first suspicion would be the power tubes. (Always suspect tubes first).

I can't comment on the value to you, but it sounds a little high to me, in unknown condition.

Thanks guys.
The owner is hesitating on selling it. He believes the filter caps are responsible for this, which I feel is unlikely and wants to change them himself. I'll keep you posted on how it turns out. Buying it is out of the equation for now, he may change his mind though.
Thanks again!