Bass Master XM100 Type:100B

[redkurn]

Try this source: https://www.findchips.com/
It queries all of the big parts houses.

Seems hopeful, the only parts that have a few extras after and curious are the BC550C and BC560C, I'll compare the specs, but the others appear to be available.

Due to environmental laws, lead content now matters for manufacturers. G on the end of a part number usually just means "green" for lead free. SOme use "PBF. Pb means lead and F for free. An MJ15024 and an MJ15024G are the same part, at least as far as you are concerned.

Good to know, but even those are discontinued or at least out of stock.

If it ends up you can't find generic, those parts are all still available through Yorkville dealers. Do you have one local that is regularly shipping product from yorkville? Prices are not bad.
You can look in the service manual for the yorkville part #'s and check pricing here: https://www.yorkville.com/support/parts_search

I'll give that a try, I hadn't heard of yorkville until I was given this amp and hoping it sounds good with a guitar being it was meant for a bass, the other bass amp I was given sounds flat, but it was a really cheap brand.
Using a Joyo Zombie through a 8 ohm (mono) / 16 Ohm (stereo) cab I built from a set of old stereo speakers at the moment.

[g1]

If it ends up you can't find generic, those parts are all still available through Yorkville dealers. Do you have one local that is regularly shipping product from yorkville? Prices are not bad.
You can look in the service manual for the yorkville part #'s and check pricing here: https://www.yorkville.com/support/parts_search

[Enzo]

Due to environmental laws, lead content now matters for manufacturers. G on the end of a part number usually just means "green" for lead free. SOme use "PBF. Pb means lead and F for free. An MJ15024 and an MJ15024G are the same part, at least as far as you are concerned.

[Jazz P Bass]

Try this source: https://www.findchips.com/
It queries all of the big parts houses.

[redkurn]

Most if not all of the original parts are discontinued and I've no idea where else to look, arrow.com, digikey.com and mouser.com do not have some of these, they do have a G series of some and out of others.
Where or how can I find proper substitutions?

Part: QTY:
MJH11017 x1
MJH11018 x1
BC550C x1
BC560C x2
2N5638 x1
BD139 x1

[redkurn]

Thanks, I can pick one of the 1.5a easily for a couple dollars in a local shop.
Hopefully the other parts will fix it, I have a 4x12 waiting to be used.

[g1]

mouser, digikey, etc. will have those fuses, but you will have to pay shipping costs. That is not considered a metric fuse, you will find it as .25 x 1.25 inch.
But I think a 1.5A slow there should be fine.

[redkurn]

I'm aware of that problem, it's how it came to me and I suspect it was the usual 'it keeps blowing 1.6a fuses, this will fix that problem' solution, I would have expected damage elsewhere, but the output stage seems to be the only fully affected.
Anyone know of a website with 1.6a slow blow 6mmx32mm in stock? Nothing available locally, closest I can find is 1.5a and I'm not silly enough to pay $8 for one fuse on amazon.

I don't doubt .1a could be a huge difference, but would it be that much? Only other I can find locally is 2a.

[J M Fahey]

4X the proper fuse size turns a $60 repair into a $200 one.

[redkurn]

I thought a variac was something entirely different, this is cool and simple to build.
I'll put one of those dim bulb testers together and test with it in place.
Jon Snell the pad was damaged from the faulty parts I would imagine, I didn't spend too much time with my iron on them and they were sucked away cleanly as if the resistor leg was all there was left holding the joint together.

[g1]

No you can't rig up a rheostat for the AC line. You can however build a 'dim bulb tester' or 'lamp limiter' fairly easily.
And yes, make sure to install the correct fuse. The 5A in there probably caused the damage to be worse than it would have been with correct fuse value.

[redkurn]

I do not have or have access to a variac, at most I could make something similar with maybe a rheostat.
Only other option available to me is to touch R55 and as @g1 said check that there is no dc voltage on the output and I am sure that I should replace the fuse that's preset with a stock rated fuse.

[Jon Snell]

Those are what are most likely to be damaged.
Change them and using a variac, monitor the quiexcent current as you slowly wind the mains up with no load/speaker connected.
If the DC voltage is around zero and the quiescent current is between 18 and 20mv, you have fixed it.
I presume the track was damaged removing the components.

[redkurn]

Anything else I should test?

So far replace Q9, Q10, Q2 and Q4, after power on and test?

[Jon Snell]

"R55 gets extremely hot shortly after being powered on" = Q4 faulty.