I don’t usually put up posts like this one, which I haven’t solved yet. It’s a bit like telling your grandma how suck eggs when you don’t know what one looks like.
“Maybe if I write something down” I thought “it might make a bit of sense?” Not so far, I’d have to admit.
I use Marshall imagebank a fair bit. Of all the companies (possibly excepting Fender and Mesa) Marshall are a million miles ahead of everybody when it comes to support. However…..
Out of the four different versions (so they say) of the AS100D I can’t find a schematic that fits it. They have been made in Korea, India, UK (?), and the one I have was built in China.
If you don’t have to take it to bits, I wouldn’t. I would prefer to take a Jaguar XJ220 gearbox to bits. Six screws on top. Easy. Two screws, one either side. Easy. Push the amp from the front and it slides out. For about two inches. It’s then that you find out about the speaker cables. There are four (two each speaker) and NO CONNECTOR. It’s hard wired into the speaker cabinet. The speaker cabinet is a totally enclosed design, so you can only get to the speaker connections by taking the speakers out. Take off the spade terminals, and then struggle to get the things through the straightjacket hole in the cabinet.
I can’t believe that an amp manufacturer of such a vast experience as Marshall has ever seen this amp. Straight from Tihibongwizzle, Taiwan to Joe Smith’s music shop Cleckheaton. Do not pass go do not collect £200. And don’t spend it in the first place if you’ve got any sense.
But we’ve not even started to fix anything. I thought I’d figured out how the schematics might fit by using this one from the Korean version, this one from the UK version, this one from the Martian version (for all I know). It seemed to work out from the outside (oh dear) but inside? The component markings were probably as relevant to a Hotpoint spin dryer as an AS100D.
The fault isn’t a desperately serious one, but having a channel low output without any control of the bass on it, is a niggle and not a great advert for Marshall either. Finding something like that fault with misleading schematics is bad news.
As a parting shot, I can tell you that in the power amp sections (there are two 50watt amps, each driving a separate speaker) are very similar in design (but not physically) to the AVT series of amps, in that they use TDA power chips. If you have a problem with blowing fuses, nasty smells, or nothing happening at all, these chips are a good place to start. They quite frequently blow holes out of themselves. That’s a dead giveaway if you’re fault finding. The AVT series have the chip(s) built onto a separate little pcb that just plugs in. Not so the AS100, but the idea is the same.
Where is the KETTLE!!!!!??????