Rivera 55 12 help

[LarBal]

Check that filter capacitor on the +24. If it is low in value or high in ESR, the regulator will appear to work at low current, but at some higher current it will look like the regulator isn't working because of huge ripple Voltage. Is there a huge 120Hz ripple at the +18V line when V1 and V2 are installed?

Well I just went ahead and pulled the board and replaced C11, the +24V cap . It's specd at 1000uf/35V, but I stuck a 2200uf/50V to test. I actually had right at 18V at pin 4 of V1 with both V1 and V2 in, then it dropped to +8V . However the plate resistor finally has a drop acroos it, 50V or something, so we're getting somewhere

When I removed the cap, there was black goo all on the board, and I had to pry it off. With close inspection, it looks like most all the electrolytics are physically leaking a bit .

[Leo_Gnardo]

When I removed the cap, there was black goo all on the board, and I had to pry it off. With close inspection, it looks like most all the electrolytics are physically leaking a bit .

Rivera uses a black stickum to hold their parts in place. So don't panic thinking that it leaked out of defective caps. The stuff they use reminds me of 3M weatherstrip cement. It sure would be a long, tedious and useless exercise to replace all the caps you think are leaking, when they are in fact perfectly healthy.

[LarBal]

Oh my, thank you for that Leo.

Well that goes along, with my new findings, that despite replacing the 24V 1000uf cap, once everything settled I'm back to square 1.

+4V on pin 4. ugh

[LarBal]

I've got the +18V suplly functioning again, turns out the 100uf/25(C13) was bad. I've got output on the amp now but apparently that's not all that was wrong with it. Sounds kinda bad, crackly, low output etc.
Any harm in leaving that C11 as 2200u, instead of 1000u ? Seems I've seen way higher that that , even, in reg DC supplies, but just want to make sure.