Rectifier Board out of Power Supply

[ljintexas]

This is a rectifier board out of a power supply from a vintage 1970s jukebox.

It is made out of unobtainium, as in extinct.
F2 and F3 are blown.CR2 is shorted, ITT is all is says on CR2
Q2 is a known weak point, but tests good, Q3 tests bad, Q1 tests bad
CR11 reads current flow both directions
CR5, 6, 7, and 8 have obviously been hot, flow current both directions. thinking I will replace them

Both large axial caps test good but are gertting replaced anyway.
Anyone have any experience with these or have any suggections?

Work on TVs mostly but this was dropped in my lap.

Thanks

LJ

[petehall347]

Re: Rectifier Board out of Power Supply

probably be as well to rebuild it all .

[R_J]

Re: Rectifier Board out of Power Supply

CR2 is a 1N4749, 24v zener, Here this should help, see page 4

[ljintexas]

Re: Rectifier Board out of Power Supply

Agreed...time for a rebuild.

Thanks

LJ

[stj]

Re: Rectifier Board out of Power Supply

there's nothing on that that isnt still being made - even the connector is a current molex one.
if they ever became needed, you could make new ones very cheaply using a chinese pcb company for the fiberglass.

[eccerr0r]

Re: Rectifier Board out of Power Supply

BTW with those molex connectors, are the pins the same for those connectors as floppy/hard drive connectors? Wondering if I can get away with getting the molex connectors without pins (I need a female 2x3 0.25" centers) and use the contacts from computer power supplies ...comes with wire attached!

[stj]

Re: Rectifier Board out of Power Supply

i dont know about stuff like retention barbs, but they will mate together.
i'v used stripped floppy cables on them by taking the contacts out of the shell and just putting heatshrink over them

[redwire]

Re: Rectifier Board out of Power Supply

It doesn't make sense, what is blown unless a gorilla was in trying to repair the jukebox.
They might have put in really big fuses for a while, or messed up connectors?

CR11 gets overloaded only if Q2 shorts.
Q1 triac is for switching on the turntable motor. It's rated 6-10A...
If F3 blows so does F4.
All electrolytic and tantalum capacitors need to be replaced due to their age and uh they didn't have vents back then so they blow up nicely.

Rockola 54875-A Rectifier Board repair

[eccerr0r]

Re: Rectifier Board out of Power Supply

i dont know about stuff like retention barbs, but they will mate together.
i'v used stripped floppy cables on them by taking the contacts out of the shell and just putting heatshrink over them

Thanks for the reminder, yes, I forgot to use the heatshrink to reduce accidental shorts. Alas it would be nice if the barbs match up, dealing with 6 pins is annoying, need to connect 4 of 6 (i.e. 360 possible combinations though really it's just 6 combinations due to the fact I know the top and bottom should be the same) and I hope it won't fall out while it's drawing 10 amps per contact ...

[stj]

Re: Rectifier Board out of Power Supply

It doesn't make sense, what is blown unless a gorilla was in trying to repair the jukebox.

these boards can be damaged by faults downstream.
and yes, jukeboxes pinball etc are often bodged by gorilla's on site to avoid having to drag it to a van and take it to the workshop.

sometimes you have spare boards to swap out but usually not.

incidentally, you need to watch out for faulty led's in the old jukeboxes - sometimes they are used to drop voltage rather than indicate stuff.
dead led can cause computers to lock up or voltages to go out of spec.

[eccerr0r]

Re: Rectifier Board out of Power Supply

oh btw, the molex hard drive connector pins do not barb up on the grid pin molex...they are different. Phooey.

[sam_sam_sam]

Re: Rectifier Board out of Power Supply

BTW with those molex connectors, are the pins the same for those connectors as floppy/hard drive connectors? Wondering if I can get away with getting the molex connectors without pins (I need a female 2x3 0.25" centers) and use the contacts from computer power supplies ...comes with wire attached!

I do not see any reason why this should not work the only thing that I would be concerned about is getting the plastic plug housing to hot and the pins not staying placed where you want to use it in but even if this happens you should be able hold them in when soldering it to the circuit board