Thanks a lot! I'll pass this info to my technician.

By the way I still live in Sweden. If anyone knows where components could be bought in Sweden I'd like to know. I got the amp from Hagström music store (they also had their own guitar brand), but it is no longer in business.

Thanks a lot! I have shared your reply with my tech guy (a former TV repair man) and he wonders if you have any ideas about how to identify the broken electrolytic cap. According to him, there are two really big ones on that card, but they are not the only ones. Are there any usual suspect that he should try to disconnect in order to measure the voltage? And why does he need a light bulb limiter? To avoid blowing more fuses during troubleshooting?

Hi, amp enthusiasts!

I have an old LAB Series L5 (100W), bought in Sweden 1980. It was a reliable work horse during the 80s, but I quit playing in the 90s and kept it stashed in the closet for some 30 years. A few weeks ago I brought it out and plugged in my guitar, but unfortunately it was out of order. Something obviously happened to it during all these years.

I have let two technicians have a look at it. Both found that two fuses are blown out as soon as the power is turned on. One of them came to the conclusion that the transformer has to be the problem. The other, who I believe is the most reliable, concluded that the transformer seems to be transmitting at least reasonable voltages (although he couldn't find out from the scheme or board layout what the exact output should be). According to his investigation, the problem rather seems to be the card "Power supply and reverb driver printer circuit board", somewhere on the part that supplies power to the power amp. When he disconnects everything else but this card, the fuses still blow when turning on the power. He can't see anything that looks burned, but something seems to short circuit, for example a capacitor.

My questions then are:

1) Are these symptoms familiar from this amp?
2) Is it still possible to get spare parts to such an old amp? Is such a card still available somewhere or could it be manufactured at a reasonable cost?