Marshall dsl 100 Pcb iss20 question

[Dennyps4]

Hey all been forever. So sorry to hear about Enzo.

Anyway I have a 2004 Marshall dsl 100. Yeah I know, ugh. I just took it in from a trade and should have known better, tested it and seemed fine at the time of trade the fired it up again and started to fart out then just faded out. Blew the mains fuse. Replaced fuse blew immediately on power up. Removed power tubes same result.
Given the history, I went ahead and ordered a new jcm2-60-00 iss20 board. Not
a serious tech, so not entirely sure if the pt blew, so my question is. Is it safe to replace the board with a possible bad pt or ot? Will it harm the new board? I will not power it back up if there’s a possibility, I’ll just take it to a tech.

I did test the board in it, (iss6) and according to the Marshall forum testing between pins 4 and 5 on the power tube sockets, it is shot. Would not exceed 397 ohms on all 4 sockets. Unplugged btw. Thanks In advance.

[The Dude]

If it was the conductive board causing the issue, replacing the board won't likely hurt anything, nor will the board be damaged by external circuitry. You can test the PT after you remove the old board (and before you install the new one) to see if secondary voltages are correct. If you are worried about the OT, check resistances from each outside winding to CT on the primary and make sure they are similar. Check that primary and secondary are not shorted. Any other OT faults are not likely to permanently damage anything.

[Dennyps4]

Thank you for the response. Think I’m going to do the swap and see how it goes the board arrived today. If I can get it to at least power up, then I can learn more.