BOP, Hummed, smoked and melted cable.

[King L.]

Well house move went well.
BOP re assembled, all cables checked and re checked, but guessing the smoke was not a good sign. (it did pass boot)
White with red tracer has shorted and melted from transformer connection block to J102, fuse is correct rating and did not see the issue .
Before I change the cable and try again, is there anything on the board which would permit the short or in view fuse111 held, have I just been unlucky, the hum noted being the short and the transformer making the most of it.
I have metered the transformer and its output is registering correct at 16vac.

Thanks in advance

Simon

 

[Ruaraidh]

Rectifier gone bad? They aren’t fused on the AC side so can present a dead short to the transformer. Worth adding fuses on the AC side to all the block rectifiers to prevent this (if that’s what’s happened).

 

[King L.]

Rectifier gone bad? They aren’t fused on the AC side so can present a dead short to the transformer. Worth adding fuses on the AC side to all the block rectifiers to prevent this (if that’s what’s happened).

 

[King L.]

Ruaraidh, thank you for you reply, appreciated.
I will remove the board, check and replace, luckily they are nice big items so soldering wont be a pain.
Other than the failed cable, there is nothing else obvious on the harness, so certainly this will be the next place to check.
And yes, they will be fused.
Kind regards
S

 

[Sgt GrizZ]

Sys 11 and Data East were susceptible to similar burned cables if bridges failed .
This board addressed it

Inkochnito's Rectifier/Bridge Board - Williams System 3-11A / DATA EAST / SEGA

Inkochnito's Rectifier/Bridge Board - Williams System 3-11A / DATA EAST / SEGA Fail Safe 18V 34V Bridge rectifier transformer brugcel condensator

www.pinballshop.nl

I know BOP is early WPC but may share similar design - I can’t recall .

 

[King L.]

Sgz Grizz
This is actually good news, both point to the same issue and rectification is easy.
It certainly made more sense for me too ask rather than throw another cable at it and see what else it could do.
Parts are on order.